A Glossary of Ecological Terms
transpired by Craig Chalquist, PhD, ecopsychologist and
author of Terrapsychology: Re-engaging the Soul of Place (2007)
- See also "Mind and Environment: A Psychological Survey of Perspectives Literal, Wide, and Deep." -
Never, no never, did Nature say one thing and Wisdom another. – Edmund Burke
The glossary that follows assumes a definition of ecology--the study of interactions between organisms and their environment--much wider than what fits under the field's habitual statistical mask. Ecofeminism and ecopsychology are mentioned, for example, as are terms from organic gardening and permaculture. Because the life sciences messily overlap (that's life), terms from botany, biology, geology, chemistry, meteorology, and agriculture are included as well.
Although designed for technical correctness and clarity, this glossary follows the practice in the Jung and Freud glossaries at this site of letting in a bit of humor here and there: for levity, for anecdote, and for an occasional thumb in the puritanical eye that closes itself to any information not dressed up in stiff, Latinized nomenclature (see the entry for English, Latinized).
Abandoned Wells: a hazard because wells left on vacated lands can channel water contaminated by pesticides and fertilizer straight down into the water table. Some states in the U.S. offer incentives for sealing off these unused wells.
Abiotic: non-living. However, see Animism.
Ablation (Wastage): surface snow and ice loss from a glacier or covering of ice or snow.
Abrasion: the wearing away of rock surfaces by small particles moved by air or water. Abrasiveness also seems to be the one quality currently shared by most political appointees and prominent heads of state. See Ontogenetic Crippling.
Absorption: the passage of water and nutrients through cell membranes instead of by direct ingestion. Also refers to how objects convert the solar radiation they receive into heat.
Abundance: the number of organisms in a given population.
Abyssal Plain: the ocean floor beyond the continental shelf.
Acequia: an irrigation ditch or canal.
Acclimation: a reversible physical change in an adapting organism in response to environmental pressures.
Acclimatization: adaptation to a different climate.
Acid: a substance with a pH less than 7 due to prevalent hydrogen ions. Acids tend to be sour and corrosive. The human stomach contains hydrochloric acid with a pH of 1; battery acid is stronger, but not by much. Contrast with Basic.
Acid Rain: precipitation heavy with nitric and sulfuric acid. Most of it is generated by sulfur dioxide and nitrogen dioxide (air pollution). Its pH is less than 5.6. Results include fish and plant deaths, corrosion, groundwater pollution, and soil erosion. Its long-term effects are unknown.
Accretion: the accumulation of marine sediments at the edges of a continent, building up in some cases into entire coastal mountain ranges. See Plate Tectonics for more about what causes accretion.
Acre: 1 acre = 43,560 sqare feet, 208.7 feet on a side, and .405 hectares.
Acre-Foot: the amount of water it would take to cover an acre of land to a depth of one foot: 325,851 gallons of water. The standard measure of agricultural irrigation.
Actinomycetes: formerly classified as fungi because of their filaments, the actinomycetales include many types of soil bacteria. They produce antibiotics, enzymes, and vitamins, although a few are harmful to humans.
Adiabatic Cooling: when air masses expand and cool as they push up the side of a mountain.
Adaptation: how living things change what they do or what they are to survive in a particular environment. In this the organism is not a passive recipient of external circumstances; the relationship is interactive. See Evolution.
Adaptive Radiation: the evolution of many new species from a relative handful of ancestor species. It often happens after some kind of catastrophe empties a range of ecological niches simultaneously.
Advection: the horizontal movement of heat energy. A warm breeze through a relatively cool orchard, for instance.
Adventitious Root: one that grows from something other than the main root.
Aeolian Landform: sculpted by wind through deposition or erosion. Examples include dunes, deflation hollows, and sand-blasted outcroppings.
Aerobic: chemical reactions involving oxygen.
Aeroplankton: tiny organisms living in the atmosphere. Certain small seeds, bacteria, and spores are examples.
Aggradation: a downward accumulation of stream-carried inorganic matter. Often has the effect of making the bed of a stream or flood plain rise. Also, a phase of forest biomass accumulation in the years that follow a harvest.
Agriculture: large-scale cultivation of the land, with resulting specialization of labor, domestication of plants and animals, identification with one’s sedentery social group, and a radical separation from the natural world. The Agricultural (Neolithic) Revolution began ten thousand years ago in the Fertile Crescent, where extensive irrigation turned once-fertile croplands into barren salt pans. (By some accounts, the now-denuded Zagros Mountains in western Iran hosted this revolution. "Zagros" is thought to derive from Zagreus, the Greek son of Zeus who was dismembered and eaten and later merged with Dionysus.) Modern agriculture largely relies on keeping ecosystems in perpetually immature states of succession in which chemically stimulated productivity remains high until the soils are too depleted to grow anything.
Agribusiness: one that markets farm products and equipment, including warehousing, seed monopolization, and fertilizer. The corporatization of farming, resulting in a handful of very large non-local companies owning and managing--and in some cases ruining--millions of high-yield acres.
Agricultural Pollution: pesticides, fertilizers, wastes, erosion dust, runoff from fields, and animal infections are a few of the varieties. According to the Environmental Protection Agency, half the water pollution in the U.S. is agricultural. (Most of the other half is industrial.)
Agroforestry: planting crops among trees.
Air Pollution: sulfur oxides and particulates from industrial plants burning fossil fuels are the current worst forms of air pollution. Auto emissions run a close second. Most air pollution derives in one form or another from the use of petroleum products, oil in particular. See Oil below.
Airshed: an area characterized by air with common qualities. Compare Watershed.
Albedo: the luminosity shining from a reflective surface. Earthshine is one type. About 1/3 of the sun’s radiation is reflected back into space, with the remaining 42% warming the land and air and 23% moving water through the hydrologic cycle. See Emissivity.
Algae: primarily marine organisms, single-celled or multicellular, that use chlorophyll to feed, like plants, but lack the roots, leaves, flowers, etc. of true plants.
Algae Bloom: explosion of a phytoplankton population, sometimes because of incoming pollutants that artificially enrich the waters with nutrients. See Eutrophication and Red Tide.
Alginate: a gelatinous extract of brown seaweed used to make a number of products, including toothpaste, beer, various medicines, paper, and frozen foods.
Alkaline: pH over 7; emits hydroxyl ions. Also called “basic.” It neutralizes the acids it combines with chemically.
Allele: alternate versions of a given gene: for eye color, for example, the blue allele vs. the brown allele.
Allelopathy: the metabolic impact of one plant on another, whether beneficial or harmful. Example: eucalyptus tree toxins that inhibit the growth of certain plants.
Allen's Rule: warm-blooded animals (endotherms) from colder climates usually have shorter limbs than do endotherms from warmer climates.
Allochthonous: something organic imported into an ecosystem from outside of it (e.g., nutrients brought by streams or blown in on the wind). Contrasts with Autochthonous.
Allogenic: originating outside a system.
Allopatric: separated, apart, as with a group of organisms living away from the original group. (There seems to be quite a bit of research done on organisms separated from their original group. It would be interesting to see a study on how many researchers feel separated from their original group.)
Alluvium: sediment transported by water, usually river or stream water.
Alpha Diversity (Local Diversity): the variety of organisms in a given habitat or location.
Alpine: above the timberline. Roughly synonymous with "mountainous."
Alpine Glacier (Mountain Glacier): a small glacier sitting in a U-shaped mountain valley.
Alternative Fuels: fuels from sources cleaner than coal or petroleum products: ethanol, methanol, natural gas, solar, wind, geothermal, biodiesel from vegetable oil, etc.
Alterne: plant communities that alternately occupy a territory.
Ambient: prevailing natural conditions studied and recorded outside rather than indoors under microscopes or other controlled conditions.
Amendment: something added to fix chemically troubled soil. Potash added to soil poor in potassium, for example.
Amensalism: a one-sidedly harmful relationship between dissimilar organisms.
Ammonia: a gaseous compound of nitrogen and hydrogen (NH3) formed as a byproduct when bacteria decompose substances high in nitrogen. Compost piles thick with manure often emit ammonia when hot. Synthetic ammonia is a key component of artificial fertilizers.
Amino Acids: ammonia-carbon acids that when strung together in long double-bonded chains (peptides) build proteins. The genetic code inscribed in DNA employs twenty of them.
Amnion: a fluid-filled sac that safely enfolds a growing mammal, reptile, or bird embryo. The amnion is thought to have allowed animals to come out of the sea onto land.
Amphibians: newts, frogs, salamanders: backboned animals that can live in water and on land.
Anabolic: metabolic processes that build tissues and organs. The opposite of Catabolic.
Anaerobic: chemical reactions in the absence of oxygen and often initiated by bacteria or archaeans (bacterialike organisms that live in extreme conditions).
Anagensis: evolutionary change, but without spilling over into speciation.
Analogue Forestry: a method for restoring ecosystems, developed from local Sri Lankan home gardens by the Neo-Synthesis Research Centre (NSRC), that seeks to bring back what grew there originally. Some key assumptions:
- The climax ecosystem is the stablest and most productive.
- Convergent evolution has provided patterns useful for ecosystems everywhere.
- Keystone species can support these ecosystems.
- Humans are integral to the biologically diverse landscapes designed.
Anapsid: a vertebrate whose skull contains no side openings behind the eyes. The only living examples are turtles.
Anemophilous: seed plants pollinated by the wind.
Angiosperms: flowering plants that place their seeds in fruits. The monocots have an embryo with a single cotyledon (seed leaf), three-part flowers, parallel leaf veins, and adventitious root growth. Dicots have two cotyledons, four- or five-part flowers, and net leaf vein patterns. Monocots include grasses, orchids, palms, and cattails, and dicots include oaks, sycamores, and maples. Compare gymnosperms.
Angle of Incidence: angle at which the sun's rays hit the Earth.
Angle of Repose: the steepest angle that slope, rock, or detritus material settles into without toppling. Builders of flood-prone roads and sliding hillside homes in California ignore the angle of repose so often that it could be renamed the angle of depose.
Animals: the animal kingdom branches into the deuterostomes (mouth and anus develop separately) and the protostomes. Animals are multicellular and possess mitochondria, a complex nervous system, and cells protected by a membrane and filled with complex organelles. 75% of all the animal species are insects.
Last summer I saw a timber wolf trotting sedately across an open dune above the water, and time without number rabbits, squirrels and birds, not feeding but seeming to enjoy the peculiar delight that beaches provide. I cannot speak for them, but is it wrong to believe that they may know something akin to the lift of spirit that is mine when standing on the sands? Is there any reason they too should not have somewhat the feeling I do there of coming suddenly out of the mountains into an alpine meadow, or a clearing in dense woods, or a plain after traversing rugged broken country? -- Sigurd F. Olson
Animism: a derogatory anthropological term for what most human cultures have believed throughout prehistory: that the Earth is alive and reactive, as are its many places. Greeks and Romans once thought a "genius loci" or spirit of place inhabited every hill, grove, and stream. Such beings still live in all human mythologies. The modern counterpart is panpsychism, the idea that all things possess qualities of mindfulness or psyche. With the coming of heavy industry, such ideas gave way to the financially convenient reduction of the Earth to the status of a lifeless resource.
Anion: a negatively charged ion. See Cation.
Anorexia: from an ecopsychological perspective, a horror of carnality so profound that it seeks to etherealize the body itself. Tends to be overrepresented in highly industrialized nations.
Annuals: pioneer plants which grow, flourish, and die in one season. Their seeds often germinate during the following wet season. See Perennials.
Antemortem: "before slaughter." The animal examination USDA meat inspectors conduct shortly before they are butchered (the animals, that is).
Anther: the pollen-producing tip of a flower's stamen.
Antheridium: the organ that produces antherozoids--male gametes (sperm cells)--in algae, bryophytes (mosses, liverworts), and pteridophytes (club mosses, ferns, horsetails). See Archegonium.
Anthophyte: a flowering plant or its closest relatives.
Anthropocentric Detour: deep ecologist George Sessions’ term for the ideological turn of mind Western civilization has taken, accompanied by occasional opportunities to return to a less human-centered way of viewing the world (e.g., Maimonides’ belief that the world was good before humans were created, and Spinoza’s thought that mind is found throughout nature). For many deep ecologists, regarding the natural world only for what it does for us exhibits a regrettable immaturity.
Anthropocentrism: human chauvinism, according to John Seed. An example is the belief that the Earth is merely a stage for human salvation or self-development without any intrinsic importance of its own.
Anticline: an arch-shaped fold in layers of rock.
Anticyclone: a high-pressure system that spirals outward clockwise in the Northern Hemisphere and counterclockwise in the Southern.
Aphelion: the annual point where the Earth is farthest from the sun (152.5 million kilometers). It falls on the 3rd or 4th of July. The opposite of Perihelion.
Aphids: soft-bodied insects that eat green leaves. Ants corral them and protect them from predators to milk them of the honeydew they excrete. Most gardeners consider them pests.
Aphytal: the plantless zone at the bottom of a lake.
Apical Meristem: the tissue-creating cells at the growing tip of a branch or root.
Aposematism: evolving a type of protective coloration found to be useful by other species.
Aquaculture: growing and harvesting fish and shellfish in land-based ponds. Relative protein yields often exceed those of land cropping by 4-20 times. Ponds attract beneficial wildlife, cool the surrounding areas, reflect sunlight, draw birds, and make convenient places for growing rice and other moisture-loving plants. See also Hydroponics.
Aquiclude: rock formations impermeable to groundwater.
Aquifer: an underground layer of sand or rock that contains usable water. Can be unconfined (down to the first impervious rock layer) or confined (between the first and the second layers). See Artesian.
Archaea: organisms that resemble bacteria but also display characteristics found in multicellular organisms. They were discovered in 1977 and tend, like so many humans of that era, to favor extreme environments.
Archegonium: a multicellular female reproductive organ in mosses, ferns, and the majority of gymnosperms. Normally flask-shaped, it corresponds to the pistil in flowering plants.
Archipelago: volcanically raised islands that arc near subduction zones where one continental plate rides over another. See Plate Tectonics.
Arête: a sharp ridge that divides cirques on a glaciated mountain.
Artesian: water pushed upward by the hydrostatic pressure of a confined aquifer. Overuse of artesian wells lowers the water table and sometimes makes nearby land sink (subsidence).
Arthropods: jointed, backboneless animals--namely, arachnids, insects, and crustaceans--often protected by a shell or exoskeleton. In evolutionary terms, this type of light armoring has proved very successful.
Asexual Reproduction: reproduction without gametes (sperm and egg) in which a single parent creates a clone of itself, often by budding or dividing itself. The offspring is genetically identical to the parent. Organisms reproduced asexually until the evolutionary invention of sex.
Assimilative Capacity: the amount of pollution a self-cleaning body of water can tolerate.
Atmospheric Deposition: contamination of land or water by atmospheric pollutants.
Atmosphere, Layers: from lower to higher:
- Troposphere: from the planet surface to roughly 7-17 kilometers up. It makes up about 75% of the atmosphere. Weather occurs here, through exchanges of heat. The outer boundary is called the tropopause.
- Stratosphere: reaches up to about 50 kilometers, where the stratopause is. Includes the ozone layer.
- Mesosphere: 50-85 kilometers up to the mesopause. Meteorites break up here.
- Thermosphere: to 640 kilometers up. Auroras appear here. The layer of molecules broken up--ionized--by particles from the sun is the ionosphere that makes radio work by bouncing radio waves back to the Earth.
- Exosphere: merges with space.
For the first time in my life I saw the horizon as a curved line. It was accentuated by a thin seam of dark blue light--our atmosphere. Obviously this was not the ocean of air I had been told it was so many times in my life. I was terrified by its fragile appearance. -- Ulf Merbold, German astronaut
Atoll: a ring-shaped reef made mostly of coral.
Atomic Mass: the weight of an atom as expressed in atomic mass units (amus).
Atomic Number: number of protons in the nucleus of an atom.
Atomic Weight: the weighted average of the masses of naturally occurring isotopes of a given element.
ATP (adenosine triphosphate): the energy molecule that powers organisms by fueling the cell's chemical reactions. It does this by surrendering one of its three phosphate groups while breaking down chemically in the presence of water (hydrolysis) into ADP. The molecular bonds that hold a phosphorus atom together with four oxygen atoms carry tremendous energy which the cell draws on for its biological work. Synthesized from glucose and fatty acids, ATP performs other functions, such as helping to build the nucleid acids that store genetic information.
Attenuation: reduction in light intensity due to a filtering medium (e.g., particles in water, a forest canopy).
Autecology: the ecology of an organism or taxonomic group; also, the study of how organisms affects plants.
Autochthonous: indigenous. Compare Allochthonous.
Autogenic: originating from within a system.
Autotroph: an organism that produces its own food. Autotrophs may be photoautotrophic (fed by using light) or chemoautotrophic (by using chemical energy). See Heterotroph.
Avulsion: sudden erosion by storm waves or rapid currents of water.
Axil: the angle that lies between a leaf stalk and its stem. Site of bud formation in flowering plants.
Azimuth: the angular distance clockwise along the horizon between north and the position of a celestial object. A star hanging exactly over the northern point on the horizon has an azimuth of 0°, for example, and one located exactly east an azimuth of 90°. Azimuth is combined with altitude (the distance of an object above the horizon) to calculate the direction of an object as seen from a specific earthly location.
Background Extinction Rate: the natural rate of extinction for a species. Contrasts sharply with Mass Extinction.
Backscattering: solar radiation reflected back into space by particles in the atmosphere.
Backshore: the strip of beach above the daily tides but within reach of storm waves.
Bacteria: single-celled prokaryotic organisms (prokaryotic means: DNA not enclosed in a cell nucleus), many microscopic. Early in Earth's history, bacteria gradually altered the environment to support more complex forms of life (producing oxygen, for instance, in the atmosphere) even while moving into cells as organelles and decomposing organic matter into soil nutrients. Hydrothermophile bacteria discovered in samples drilled from deep in the earth give new support to Thomas Gold's idea that life originated in hot, high-pressure crevices underground.
Bacteriophage: a virus that infects and eventually kills its bacterial host. Genetic engineers study phages to learn more about how some implant their DNA into the host, an invasion somewhat akin to the contamination of research laboratories by military-industrial sponsorship.
Badlands: rough land eroded into arid barrenness. Also, a part of South Dakota.
Bajadas: lower mountain slopes covered with loose sediment, possibly from runoffs. Example: overlapping alluvial fans rolling along the base of arid peaks.
Baldwin Effect: the hypothesized passing on of something learned, but not through the discredited Lamarckian theory of evolution (the inheritance of what previous generations experienced). Walking upright could be an example, as a band of our ancestors imitated some forgotten hominid who preferred that style of locomotion and then gave rise to descendants whose genes favored the behavior. The Baldwin Effect fills in a gap in how natural selection is thought to work by explaining how learnings normally invisible to it become innate.
Barchan: a crescent-shaped dune whose tips point to leeward. Different from a Seif.
Barrier Beach: a long strip formed by sand deposited across the mouth of a harbor or inlet. They are often duned, and many separate an area of marshland from the sea.
Barrier Island: a narrow sand island that parallels a shoreline.
Basal Area: a forest's tree density expressed in square feet.
Basal Sliding: the downhill sliding of a glacier propelled by its weight.
Basalt: a dark, extrusive, igneous rock made of particles so fine they can't be seen unaided. Formed from mafic (high in heavy elements) magma. See Felsic.
Base Flow: a stream or river's normal flow volume.
Base Level: the altitude below which a stream cannot perform vertical erosion. Usually, sea level.
Basement Rock: the ancient granitic and metamorphic rock that constitutes continental crust and the continental shield.
Basiphile: a plant that favors basic soils (those low in acid).
Batholith: a huge mass of igneous rock, usually granitic, that formed deep underground and only surfaced through erosion of the overlying mountainous material. Often found near plate edges (see Plate Tectonics). The Sierra Nevadas are a well-known batholithic formation.
Bathymetric: scientific-sounding term for measuring something in deep water.
Bayou: an inlet or outlet, often marshy. A slough.
Beach Drift: the sideways movement of beach sediment.
Beaufort Wind Scale: wind speed scale developed in 1806 by Admiral Sir Francis Beaufort of the Royal Navy. Reaches from 0 (calm) to 12 (hurricane).
Bedding Plane: a layer that indicates a change in the type of sediment (e.g., where sand gives way to shale).
Bed Load: stream load material carried along the stream bed without falling into suspension.
Bedrock: more or less unweathered rock near the surface.
Benthic: organisms living on the sea floor. Littoral benthos occupy the space from the high-water spring tide mark to 200 meters down. Deep sea benthos live below that.
Bergmann’s Rule: warm-blooded animals in cold climates tend to be larger than animals of the same species living in warm climates.
Bergschrund: a deep crevasse usually opened by ice at the head of a moving alpine glacier.
Berm: a level, narrow ledge or bench that divides a stream or separates water from land, as in a canal path.
Biennial: plants that live two growing seasons; they fruit during the second.
Bight: a small coastal indentation open to the sea.
Bilateral Symmetry: body divisibility into mirror-image halves (right and left arms and legs, for example). Animals with bilateral symmetry display dorsal (top), ventral (bottom), anterior (front), and posterior (rear) orientations, whereas radial animals like starfish have only the dorsal and ventral. (Arms, legs, and wings evolved from the fins of lungfish swimming around over 400 million years ago.)
Biocenose (Biocenosis): the interacting organisms living together in a habitat. A biotic community.
Biocentric: putting the natural world, rather than the human world, into the perceived center of the cosmos. The land is not made for us: we are a part of it.
Biochemical (Biological) Oxygen Demand (BOD): the amount of oxygen required to dissolve and decompose organic matter. A water quality measurement often applied to treated sewage.
Bioconcentration (Biomagnification): the strengthening of a harmful and usually toxic substance as it moves up the food chain, as with DDT growing 400 times deadlier in seagulls and other carnivores than when first ingested by marsh animals.
Biocontrol: using natural means like predators to control pests, like growing ginger to repel snails and slugs and nasturtiums to ward off aphids, which are also food for ladybugs and lacewing moths. Goldfish placed in water storage containers eat incoming mosquitos.
Bioculture: Paul Taylor’s term for how humans exploit other living things: domesticating animals, force-feeding livestock, etc.
Biodegradable: reducible by bacteria as opposed to something that remains in the environment (plastic, certain inustrial wastes).
Biodiversity: biological variety of the kind that preserves species and their DNA. R. H. Whittaker categorized it (1972) as alpha, the number of species in an ecosystem; beta, the diversity between ecosystems; and gamma, the diversity of entire regions. Depleted biodiversity leads to population crashes, declines in genetic variability, and extinctions.
Biodynamic Farming: alternative farming practice and philosophy introduced in eight lectures in Austria by Rudolf Steiner in 1924. Three of its techniques: Horn Manure Preparation to introduce stirred nutrients into the soil, Horn Silica Preparation to nourish plant growth, and Compost Preparations. Cycles such as those of the moon are also taken into account in order to build up humus and productivity. Alan Chadwick combined biodynamic methods with French Intensive procedures in the late 1960s and founded an experimental farm and garden at UC Santa Cruz. (Word has it that he was a gifted horticulturalist but highly competitive.)
Biogas: a methane and carbon dioxide emission due to the breakdown of organic matter by anaerobic bacteria. Some trap it for use as an alternative fuel source.
Biogeochemical Cycles: the great loopings and returns of life-giving substances through the environment. The three most important are the gaseous (e.g., the carbon, oxygen, and nitrogen cycles), the sedimentary (including the phosphorus, sulfur, calcium, magnesium, and potassium cycles), and the hydrologic (water vapor to rain to streams to oceans to vapor). Uninterfered with, these cycles tend to be self-organizing and self-renewing.
Biological Weathering: weathering helped along by living things, like plants that break up layers of rock.
Bioluminescence: light emitted by chemical reactions within living things (fireflies, glow worms, jellyfish, etc.). Uses: to communicate, escape predators, attract prey.
Biomass: the total quantity of living matter in a given area or ecosystem.
Biome: the largest ecological regions distinguishable by characteristic plants and animals. There are six: tundra, conifer, deciduous forest, grassland, tropical, and desert. Biomes are subdivided into associations made up of societies.
Biointensive Method: an alternative high-yield farming method devised by John Jeavons. Drawing on traditional Chinese practices, Steiner's biodynamic farming, and French Intensive, the biointensive approach aims to grow soil rapidly, cut water consumption, and maintain optimal food production (the claim is that 100 square feet can feed one person for a year). The keystone: double-dug raised convex beds a meter or two wide oriented in a north-south axis for adequate sunlight. Small paths between rows minimize soil compaction and maximize plant microclimates. Leaves of mature plants just touch ("living mulch"). Steps for initial bed preparation include:
1. Soak area for two hours, let dry for two days.
2. Loosen soil 12 inches deep with a spading fork and remove weeds.
3. Water for five minutes and let soil rest a day.
4. Spread compost, water five minutes, let soil rest a day.
5. Double dig to 24 inches; dig, don’t pulverize, and don’t turn over the upper layer. Dig when moist to avoid wrecking the soil structure.
6. Rake level, water 5 minutes, let rest a day.
7. Compost with a 50% soil mixture.
8. Plant seeds in beds 2-10 inches high. Space seeds hexagonally.
10. Water lightly daily in late afternoon.
See Double Digging.
Biophilia: love of nature. Coined by biologist E. O. Wilson. The opposite of necrophilia, the love of dead things.
Biopiracy: the business practice of patenting seeds and other indigenously grown agricultural products. Monsanto, a key sponsor of Disneyland and developer of nuclear arms, is forcing financially strapped farmers in Bangladesh to buy seeds once passed down through families. POD-NERS has done something comparable in Mexico and has sued Mexican yellow bean exporters for patent infringement. See also Seed Saving.
Bioregion: a naturally bounded, ecologically distinct geography: a watershed is one example. Term coined by Peter Berg and Raymond Dasmann. The largest bioregion is an ecoregion (example: the Ozark Plateau), the next largest a georegion (river basins, mountains, watersheds), and the next a local morphoregion. As Berg described it:
A bioregion refers both to geographical terrain and a terrain of consciousness--to a place and the ideas that have developed about how to live in that place... A bioregion can be determined initially by use of climatology, physiography, animal and plant geography, natural history and other descriptive natural sciences. The final boundaries of a bioregion, however, are best described by the people who have lived within it, through human recognition of the realities of living-in-place....
Bioregionalism: philosophies, ecological practices, and politics built around the idea that a place’s natural features and edges suggest the basis for understanding it and inhabiting it. Scientifically, this means joining ecology to anthropology through geography: a seamless interdependency between ecosystem, culture, and region. Most versions of bioregionalism share the following areas of focus:
- Those who actually live in a bioregion know best how to manage it. Top-down solutions from far away are to be suspected.
- Dwellers begin to understand a place by reinhabiting it, which means learning all about its ecosystems and animals, water sources, weather, soil types, waste management, ecological strengths and traumas, and resources for ecologically gentle living. The mood that matches this is learning to feel at home there.
- Food is best grown and bought locally.
- Local democracy is based on direct participation and small-group discussion. (As Leopold Kohr put it, "If something is wrong, then something is too big.")
- Developments that would damage the local environment--shopping malls, tract housing, factories, etc.--should be firmly and consistently opposed. Locally made products are preferred over those shipped from a distance or made locally through mass production both of which transfer capital to outside sources.
- Respect for the rights, needs, customs, privacy, and knowledge of indigenous people living in the area.
- Living sustainably means ecologically sensible practices such as reuse and recycling, water and power conservation, and reduction of trash and other wastes.
Biosphere: taken together, the troposphere, oceans, and land surfaces where things live. Also called the Ecosphere.
Bioremediation: using animal microorganisms or plants (phytoremediation) to heal polluted soil or water.
Biotic Community: a self-sustaining community of living things. An ecosystem.
Biotic Factor: the environmental influence exerted naturally by living organisms: worms that aerate soil, animals that enrich it with manure, trees that throw shade, etc.
Biotic Potential: a population's maximum production rate given ideal surroundings and resources.
Biotope: an environmentally uniform area. The physical aspect of an ecosystem.
Bioturbation: when organisms disturb sediments, as with worms on the ocean floor that eat food stuck between sand particles.
Bird: according to one source, a vertebrate whose body is covered with feathers. For more on this, see Pedanticism.
Bisporangiate: a flower's capacity for producing both megaspores (female spores) and microspores (male spores). Most flowers are bisporangiate.
Black Body: in theory, a body that absorbs and emits 100% of the electromagnetic radiation that strikes it and therefore appears black. Graphite comes close, with all but 3% absorption.
Black Box/White Box: a research protocol that distinguishes between "black box" approaches where the researcher manipulates an unknown, and "white box" approaches where knowledge of how something works determines the methods used to study it. By and large, ecology confines itself to black box methods by looking at natural events from the outside, "objectively," whereas deep ecology, ecopsychology, and other more interactive perspectives strive to be in touch with the inner workings of nature.
Blowout: a depression caused by erosive wind.
Blue-Green Algae: the old term for Cynobacteria.
Board Foot (MBF): a measure for lumber equivalent to a one-inch thick board one foot long and one foot wide. Often used to determine the amount of wood cut from a forest.
Bog (Heath, Muskeg): marshy land covered by shrugs and mosses. Their acidic soils accumulate peat, the thick, carbonized vegetable tissue decomposed in water. The words "bogeyman" and "heathen" derive from outcasts who inhabited these poorly drained areas.
Bolson: a mountain-ringed desert basin lacking any outlet for drainage.
Bolt: the explosion of seeds from cool-season plants suddenly exposed to warmth.
Bonemeal: an amendment that adds phosphorus to soils that need it. See Macronutrients.
Boreal: of the northern latitudes.
Boreal Forest (Taiga): the high to mid-latitude biome characterized by coniferous forests inhabited by fir, pine, spruce, larch, and cedar standing on previously glaciated land. Stretches across North America, Europe, and Asia.
Botanical (or Plant-Derived) Pesticide: one derived from plant chemicals (e.g., strychnine).
Bottomset Bed: a fine, horizontal delta deposit of alluvial clay and silt.
Bowen Reaction Series: N. L. Bowen's generally accepted hypothesis that how rocks crystalize from magma--whether they turn out mafic, intermediate, or felsic--depends on the magma's composition and temperature.
Brackish Water: water contaminated by salt, but with a salinity lower than 35 parts per thousand. See Brine.
Braided Stream: a watery network of twisting, sediment-bearing channels. Found atop alluvial fans.
Breaker: a wave that collapses forward near the shoreline as the shoaling sea bottom makes it top-heavy. It collapses when the ratio of its height to its wavelength passes 1:7.
Breccia: coarse sedimentary rock composed of sharp, angular rock fragments cemented together. Contrast with Conglomerate.
Brine: seawater with a salinity greater than 35 parts per thousand. Brine is often made salty by evaporation.
Buffer Prey: a species targeted by a predator that usually eats a different species. This happens when the preferred species is depleted or the buffer species is unusually numerous.
Buffer Strips: lines of vegetation planted between crops to reduce runoff and erosion.
Bulgur: dried, ground, sifted, partially debranned, and parboiled (precooked) wheat for whole grain use.
Bundle: a bioregional summation of a place. It usually includes a map, information about notable plants and animals, a historical outline, facts about early dwellers, photographs, a brief environmental assessment, and in some cases journal entries and artwork.
Bush Fallow: secondary tropical or subtropical vegetation planted in forests in order to regenerate the soil between crops. In places like western Sudan, this traditional practice has been subverted by a Western emphasis on cash-producing monocrops in disregard of cultural or ecological consequences.
Bushel: a dry volume measure of fruit and vegetable products equal to four pecks or eight gallons (2150.42 cubic inches).
Butte: a steep, craggy, isolated hill with a top less flat than that of a mesa.
Buttons: small broccoli or cabbage heads grown from seedlings exposed to freezes.
Buys-Ballot's Law: standing somewhere in the northern hemisphere with your back to the wind locates the low pressure area driving it on your left. The reverse is true in the southern hemisphere. See Coriolis Effect.
Bycatch: accidental harvest of one organism instead of another, like the crustaceans caught in shrimp trawls and the dolphins trapped instead of tuna.
Calcareous Soil: soil rich in calcium carbonate (calcite) deposited by weathering of calcareous rocks and shells. Chalk, limestone, marl, magnesium, and phosphates are often found in it, making it fertile, if dry or thin. Often seen in deserts.
Calcicole: a plant that likes high-calcium soil.
Calcification: accumulation of calcium carbonate in upper soil layers. Frequent in semi-arid areas and in grasslands.
Calcifuge: a plant that avoids calcareous soils.
Calciphile: a plant confined to calcareous soils.
Caldera: a circular volcanic crater larger than the vent.
Caliche: surface soil particles cemented together by lime (calcium carbonate). Lumps of it can block water, curtail root growth, and cause iron deficiency in nearby plants.
Calorie: a quantity of energy equal to the amount of heat required to raise one gram of pure water from 14.5 to 15.5° Celsius under standard atmospheric pressure.
Calving: breaking off of sheaths of ice from icebergs; a form of Ablation.
Calyx: the sepals (outer leaves covering the bud) of a flower.
Cambrian Explosion: supposed huge diversification of multicellular life forms in the Earth's oceans during the Cambrian Period 570 million years ago. All that’s certain is that organisms living before the “explosion” did not leave behind many fossils.
Cambium: the cell-generating tissue between the bark and the stem. Usually absent in monocotyledonous (see Monocot) plants.
Candle: new shoots on needled evergreens.
Cane: a grapevine shoot one year old.
Canopy: a tree's uppermost layer: branches and leaves.
Capillary Action: water movement through tiny absorbent channels, often against the force of gravity, made possible by water's firm hydrogen-oxygen bondings. Capillary action plays a major role in water diffusion through soils and organisms.
Carbohydrates: compounds of oxygen, hydrogen, and carbon formed into the sugars, starches, and cellulose formed by plant photosynthesis of water and carbon dioxide. They provide energy and facilitate fat production. Three primary types: monosaccharides (simple sugars like fructose and glucose), disaccharides (lactose, maltose, and sucrose), and polysaccharides (cellulose, glycogen, dextrin, starch). Foods that provide carbohydrates include breads, beans, dairy products, potatoes, corn, many sweet deserts.
Carbohydrate Catabolism: a three-step breakdown of glucose into energy (ATP) inside the mitochondrion, the cell's power plant: glycolysis, the Krebs cycle, and oxidative phosphorylation.
Carbon: an element whose atoms have six protons and six electrons. Because its outer electron shell holds only four of the eight electrons it could support, carbon bonds easily with other elements and with itself to fashion the complex molecules on which life as we know it depends. It makes up almost half of the human body's dry mass.
Carbonation: a type of chemical weathering in which carbonic acid (carbon dioxide dissolved in rainwater) reacts with the magnesium, potassium, sodium, or calcium in rocks like limestone and feldspar and thereby dissolves them, sometimes forming caves.
Carbon Cycle: the passage and recycling of carbon through the plantary biosphere, lithosphere, hydrosphere, and atmosphere.
Carbon Dioxide: a colorless atmospheric waste-product gas (one carbon atom joined to two carbon atoms) produced by combustion, fermentation, and respiration. Fossil fuel consumption and deforestation have almost doubled the quantity of it in the atmosphere. See Greenhouse Effect and Photosynthesis.
Carbon Flux: carbon movement; movement of organic compounds through an ecosystem. Specifically, the relationship between carbon dioxide absorbed by green plants and carbon dioxide respirated by various organisms.
Carbon Sinks: sites that soak up carbon (forests).
Carcinogen: a substance that fosters cancer, an illness characterized by cells that cannot quit dividing in a kind of biological nation-statism.
Carr: a wet area of deciduous scrub or woods grown from swampy soil.
Carrying Capacity: the maximum poplation an ecosystem can support of a given species. An ongoing debate focuses on whether the Earth's carrying capacity for humans has already been exceeded or shortly will be.
Casein: a tasteless white protein distilled from milk and used in dessert toppings, coffee whiteners, adhesives and binders, paint, and plastics. Sensitivity to it plays a role in milk allergies, Asperger's Syndrome, and Autism.
Catabolic: metabolic processes that break down tissues and organs--turning protein into energy during a fast, for example. The opposite of Anabolic.
Catchment: a natural or artificial basement for trapping water. One natural version catches rainfall and feeds it into a stream that drains the catchment area.
Cation: an ion carrying a positive atomic charge. Many key soil nutrients employ cations.
Cation Exchange Capacity: how well a soil hosts exchanges of cations between its minerals and its plant roots. In general, soils high in clay and organic matter carry a negative charge that retains plant nutrient cations against leaching away. High CEC usually correlates with high fertility.
Cavitation: fast or even explosive erosion forced by air bubbles carried by a rapidly flowing liquid. Ruins its share of water pumps.
Cell: makers and maintainers of protoplasm; the basic living unit of all organisms except viruses. The cells of organisms other than bacteria are eukaryotes: those containing a defined nucleus in which chromosomes contain the DNA recipes from which cells synthesize protein. Cells know what to do and which genes to turn on because of what surrounding cells do in reference to a chemical-directional gradient. In organisms of greater complexity cells specialize into a variety of tissues.
Animal cell diagram. From the textbook Human Biology (Daniel Chiras, published Jones and Bartlett, 2002)
Cell Grazing: concentrating grazing animals like sheep to promote soil aeration and fertilization one bloc of land at a time. Overgrazing and plant-killing trampling are prevented by moving the animals along before it happens.
Cellulose: an insoluble, fibrous carbohydrate that reinforces the cell walls of plants, green algae, and dinoflagellates.
Celsius Scale: temperature scale in which water freezes at 0° and boils at 100°.
Centrifugal Force: the force that pushes an orbiting object out of its circular path. "Force" is a misnomer, however, because without the centripetal force, the object would naturally straighten its course in accordance with Newton's First Law of Motion, which states that objects tend to move in a straight line through space unless acted upon by an outside force.
Centripetal Force: force required to hold a moving object in a circular path against its tendency to fly outward. Spinning storms like hurricanes and dust devils exhibit it. The force is proportional to the square of the velocity, which means that doubling the object's speed increases the centripetal force four times.
Cereals: grasses cultivated for their edible seeds (grains). They include wheat, rice, maize, barley, oats, and rye. Around the world, they are grown more often and more abundantly than any other crop.
Cetaceans: the order that includes dolphins and whales. (Closest living relative to the whale: the hippo.) Like the Order Sirenia (manatees and dugongs), the Cetaceans were never land animals.
Chalk: a type of limestone sedimented together from the skeletons and shells of marine microorganisms; it resists erosion but is porous, often gathering a lot of water beneath its formations.
Channelization: altering a stream by straightening, diverting, or dredging, usually to make it run faster.
Chaparral: an evergreen shrub community adapted to dry seasons. Although it secrets a resin that burns like gasoline, homes continue to be built in its potentially explosive thickets.
Character Displacement: given two species that might need to compete for a resource, the members least like each other in what they require tend to survive and reproduce long enough to evolve into species whose niches do not involve competition. So far, this principle has not worked its way up the food chain into the dealings of nation-states with each other.
Chela: the claw of an arthropod.
Chelate: a ring-shaped compound consisting of metals chemically bonded to organic residues. Metalloproteins, for example, that work in the body with enzymes and iron storage.
Chelation: chemical weathering in which chelates draw metallic cations (positively charged ions) out of rocks and rocky minerals. Ultimately, all forms of weathering have a hand in forming soils. Also: a controversial medical procedure in which the organic chemical EDTA is injected into the body to chelate heavy metals from the blood. The list of claimed benefits includes help for atherosclerosis and various kinds of vascular disease, decreased angina, nicer skin color, healing of gangrene, better blood viscosity and circulation, fewer free radicals, smoother cell and organelle functioning, heightened sensuality, healed ulcers, diminished arthritis, MS, Parkinon's, and Alzheimer's, and of course slower aging. Proponents whose praises for chelation are ignored claim to be victims of the medical establishment, their clinking heavy metals chelated by a disbelief freely played if not always radical.
Chemical Autotroph (Chemolithoautotroph): a guitarless organism that feeds itself chemically (chemosynthesis), as some bacteria do.
Chemical Weathering: chemical decomposition of minerals and rocks. Types: oxidation (substances dissolved in oxygen--iron oxidation, for instance), hydrolysis (in acidic water), carbonation (limestone dissolved in water), hydration (weathering through water absorption), chelation.
Chemigation: dispensing a pesticide through an irrigation system. Sprinklers are often used for this.
Chemosterilant: a chemical that stops pests from reproducing.
Chemosynthesis: the chemical conversion of inorganic compounds found in an autotrophic organism's surroundings into food for it. Compare Photosynthesis.
Chernozem Soils: soils rich in humus and calcium, like the soils often seen in meadows and prairies.
Chert: hard and dense sedimentary rock, light gray to dark gray (flint), composed of quartz crystals and silica derived from marine fossils. Usually found in limestone nodules.
Chimera: an artificially created animal composed of mixed DNA. A human with a mouse's brain would be an example, as would Frankenstein's angry monster. In Greek mythology the Chimera--a fire-breather who was part lion, part goat, and part dragon--devastated the land until finally slain by a hero. Nevertheless, certain enthusiastic biologists are more eager to create chimeras than to read hints and warnings from ancient mythology.
Chinampa: a maze of raised crop beds (camellones) on low, canal-fed islands of mud, clay, manure, and decomposing plants built up in lakes and ponds. Aztecs and Mayans used this farming method.
Chinook: a warm, dry wind that blows on the lee sides of mountains in North America.
Chitin: an aminosugar and polysaccharide (an insoluble carbohydrate spun from interwoven simple sugars) found in some fungi cell walls and in insect exoskeletons. Although abundantly produced--almost as much so as cellulose--some insecticides prevent it from cycling.
Cloche: a transparent plant cover that shields plants from the cold.
Chlorofluorocarbons (CFCs): nonburning chemicals made of carbon, chlorine, and fluorine and used in aerosol sprays, solvents, foams, refrigerants, and packing materials. When released into the air and exposed to ultraviolet radiation in the upper atmosphere, they form a gas that opens holes in the ozone layer.
Chlorophyll: a green, sunlight-capturing pigment in plants and some bacteria. See Photosynthesis.
Chloroplast: a cell organelle, once a free bacterium, that holds chlorophyll. Symbiotic with mitochondria, as shown by biologist Lynn Margulis.
Cholinesterase Inhibitors: chemicals that inhibit the enzyme that manages neural activity. Found in many insecticides (carbamates, Parathion, Mestinon). Used in small doses to relieve the symptoms of Alzheimer's disease and other dementias.
Chordates (Phylum Chordata): animals with a notochord--a long, cartilaginous support column running most of the body's length--located between the stomach and a fluid-filled dorsal nerve cord.
Chromatin: the combination of DNA and the structural proteins (histones) it wraps around in the cell nucleus. Chromosomes are made out of chromatin.
Chromosome: a long, threadlike structure that carries the bearer's genetic code (DNA), among other things. Humans have 23 pairs of chromosomes, 46 in all: 44 autosomes and two sex chromosomes, the X (female) and less complex Y (male). Offspring acquire half their chromosomes from the biological mother and half from the biological father. Each chromosome is shaped like an X, with a dot in the center (the centromere) and arms reaching out to the ends (the irreplaceable telomeres that keep chromosomes from sticking together accidentally; their gradual shortening from replication after replication during cell division sets the biological limit to a life). See Gene, DNA.
Circum-Pacific Belt (Ring of Fire): a zone of volcanoes and volcanic islands circling an edge of the Pacific Basin where one continental plate grinds under another (subduction). See Plate Tectonics.
Cirque: a large, glacially eroded bowl on rocky mountains. Alpine glaciers generally start out from a cirque.
Cities: urban systems whose dominant members occupy various niches, some of which compete. Rather parasitic, the large ones, in that they take from all over without giving, bereft as they are of natural producers. Because of their exclusive emphasis on growth and productivity, they are locked into an ecological immaturity that wastes resources and widely and indiscriminately pollutes. For all these reasons they are as unsustainable as the civilizations that spawn them.
As Homo sapiens’s entry in any intergalactic design competition, industrial civilization would be tossed out at the qualifying round. -- David Orr
Citric Acid Cycle: see Krebs Cycle.
Clade: a group of organisms that includes their most recent common ancestor and all of their descendants.
Clast: a single constituent of a rock (e.g., a grain).
Clastic: composed mostly of former rocks (like shale and sandstone) whose fragments have been carried a long distance from where they originated.
Clear-Cutting: removing all the trees from a given area; a destruction of entire forests at a time.
Cleavage: natural plane of breakage along which consecutive breaks produce smooth, parallel splits.
Cleptobiosis: when one species steals food from another.
Climate: average atmospheric conditions over a long time interval. Energy from the sun drives climate, which sets limits on a biome's plant life and therefore on the animals that live there. The Koppen-Geiger classification sorts major climates into five types: humid tropical, dry, humid warm, humid cold, and cold polar.
Climax: the culminating stage of plant succession in a given ecosystem. Climax communities tend toward maturity because of having attained harmony with their surroundings through years of experimentation and adaptation. See Succession.
Cline: a gradient of variations in a species that stretches across a geographical location. Example: different types of eucalyptus trees running across a series of slopes.
Closed System: one that exchanges energy, but not matter, between itself and its environment. The Earth is a closed system of finite room and resource.
- Cumulonimbus (thunderheads): near ground level to above 50,000 feet.
- Cirrostratus: above 18,000 feet.
- Cirrus: above 18,000 feet.
- Cirrocumulus: above 18,000 feet.
- Altostratus: 6,000-20,000 feet.
- Altocumulus: 6,000-20,000 feet.
- Nimbostratus (rain): below 6,500 feet.
- Stratocumulus: below 6,000 feet.
- Cumulus (fair weather): below 6,000 feet.
- Stratus: below 6,000 feet.
* Take every typology with two grains of salt. Nature knows no rigid categories.
Coal: hydrocarbon and sedimentary rock composed of compacted plant remains, mostly ancient club moss trees sitting above tropical swamps. Mined coal provides most of the world's electrical energy. A popular compound in hell, it was once carried by thieves and cutpurses to avoid apprehension.
Coarse Particulate Organic Matter (CPOM): unprocessed carbon compounds added to an aquatic environment. Example: straw or leaves blown into a pond. Microorganisms eventually break it down into FPOM (Fine Particulate Organic Matter).
Cobble: pebbles rounded by being bounced around in water.
Codominant: two tree species (hickory and oak) with roughly equal populations and ecological impact in the forest they grow in. Also, the blended expression of two alleles (genetic variations), as when white carnations crossed with red carnations produce pink ones. See Allele.
Coevolution: interactions between species that impact how both evolve. Examples: bees and plants needing pollination; the cleaner fish and the whale shark.
Col: saddle-shaped depression between mountain peaks. Formed by opposing cirque glaciers.
Cold Frame: a glass-covered frame (often of wood) that houses seedlings and delicate plants. Contrast with Hot Frame.
Collagen: long proteins stretched into a triple helix to make strong structural fibers. They are found in hair, tendons, and about a fourth of the human body's protein.
Colonial Nesting: the habit of certain birds--egrets, swallows, herons--to build concentrated colonies. (Historical note: One year a radio microphone was set up at Mission San Juan Capistrano to convey the flappings of departing swallows to listeners all over heavily colonized Orange County, but the inconsiderate avians flew off ahead of schedule. The missionaries had done something similar in 1834 when the mission was secularized.)
Colony Forming Units (CFU): bacterial colonies cultured from a water sample. CFUs indicate the water's level of bacterial concentration.
Combine: a grain harvester that combines cutting, threshing, separating, cleaning, and straw dispersing as it moves across cropland. Australian farmer Hugh Victor McKay invented the first practical combine in 1882; as devout a Christian as Sven Foyn, inventor of the harpoon gun, he fought against the establishment of basic wages for agricultural laborers but lost that battle. James Morrow invented a similar threshing and stripping device around the same time that McKay did.
Commensalism: a coevolutionary relationship between species (usually animal species) that benefits one without significantly impacting the other.
Commoner’s Laws of Ecology: 1. Everything is connected to everything else. 2. Everything must go somewhere. 3. Nature knows best. 4. There is no such thing as a free lunch, or everything has to go somewhere. (Barry Commoner, biologist, 1971.)
Community Coefficient: a measure of similarity between the plants and animals of two different ecological communities.
Companion Planting: planting plants that do well together near each other. Here are some:
- Marigolds around tomato and pepper plants.
- Asparagus and parsley.
- Beans with potatoes, carrots, cucumbers, kohlrabi, spinach, strawberries.
- Basil near tomatoes, eggplant, and peppers.
- Carrots near beats, radishes.
- Slow thistle with lettuce.
- Corn to shade cucumbers.
- Mustard near cabbage and cauliflower.
- One spinach plant per four Bibb lettuce plants.
Some combinations to avoid (opponents):
- Dill with carrots.
- Apple trees with potato seedlings.
- Beans or peas near garlic, onions or shallots.
- Wormwood with anything; eucalyptus with anything.
Competition: for food and resources. Types: interference (by direct attack), exploitation (forced to share a resource), scramble (everyone gets something), contest (one competitor gets it all), and restrictive (preventing someone else from getting it); also, inter- and intraspecific modes (between or within species). Competition tends to characterize less mature ecosystems. Note: there is some debate about how much of the "competition" and "dominance" we see in the natural world is projected there by observers who take such behaviors in overmanaged human societies for granted.
Competitive Exclusion: where one species competes another into extinction.
Composting: enriching a soil's nutrition and CEC (cation exchange capacity) by adding decomposed organic matter to it. Grass clippings, kitchen scraps, coffee grounds, and even certain kinds of weeds will serve when mixed with brown matter (dry twigs, newspaper), but not animal fat, meat, oil, or cat or dog feces. A properly built, moistened, and aerated pile will gradually heat up as microorganisms break it down into humus; for faster results, shred the materials before composting, keep sponge-moist, and turn the pile every three days, shoveling undigested matter at its edges into its baking heart. It is ready to spread on soil when flaky brown and no longer hot. A thin layer of soil on the pile gets it off to a start. A pile of less than three cubic feet may not heat up properly.
Compound: a substance composed of various elements.
Condensation: the transformation of (water) vapor into liquid. Falling temperatures trigger it.
Condensation Nuclei: microscopic particle of dust, ash, etc. around which a raindrop forms. Drops also form around silver iodide particles seeded into clouds to increase local rainfall.
Cone of Depression: the drop in the water table near an overused well, resulting in a cone-shaped dry zone called an area of influence.
Connectance: the actual food web interactions between species compared with the total possible number; usually expressed as a fraction.
Conglomerate: coarse sedimentary rock composed of weather-rounded rock fragments cemented with silt and clay. See Breccia.
Conifer: a cone-bearing tree. Coniferous vegetation occupies the middle and high latitudes.
Conjunctive Symbiosis: a mutually beneficial relationship in which the two participants join into a single organ or body. Example: lichens.
Conservation Tillage: any planting approach that leaves 30% or more of the soil covered by plant residue or cover crop while tilling as little as possible to avoid destroying the soil structure.
Constancy: the dispersion of of a species throughout a community. A constant is a species that shows up in almost every sample taken (indicating an occupation of roughly 80%).
Consumer: an organism that consumes other organisms, whether living or dead. Compare Producer.
Consumerism: the mass delusion, supplemented by expensive advertising, that using up as many products as possible as quickly as possible will somehow not cave in the biosphere. See Dieback.
Contact Metamorphism: alteration of rock by localized high temperatures and fluids circulating near a cooling mass of extrusive igneous rock (a pluton).
Continental Crust: the predominantly granitic rock that comprises the stony foundations of the continents. (Ocean floors are composed primarily of basalt.) The crust's thickness varies from 20 to 75 kilometers. See Earth, Layers.
Continental Divide: the elevation that divides a continent's largest drainage basins.
Continental Drift: the theory that continents are mobile rather than fixed. Proposed by A. Snider in 1858. See Plate Tectonics.
Continental Effect: the seasonal temperature differences that land surface heating and cooling have on local climate. The differences tend to be greater than in places closer to an ocean (maritime effect).
Continental Margin: the interval between the shore and the ocean floor; includes the continental shelf, rise, and slope. Active margins mark sites of heavy geological activity, including continental collision and subduction. Earthquakes, volcanism, mountain formation, and a narrow continental shelf characterize the tumultous active margins. Passive margins are the opposite, calmer and steadier, with flat land and wide shelves. In North America, the west coast is active and the east coast passive.
Continental Plate: a rigid, primarily granitic slab floating on the asthenosphere, a layer of semi-molten upper mantle. The plates average 125 kilometers of thickness and are pushed rather than pulled by currents in the mantle. (See Plate Tectonics.) The continents riding atop the plates occupy 29% of the planet surface.
Continental Shelf: the more or less level sedimentary interval from the shore to the continental slope that leads deeply downward to the ocean floor.
Continuum: subtle gradations in plant or animal communities within an ecosystem.
Contour Farming: farming perpendicular to the slope of a hill or mountain, instead of straight up or down it, to minimize runoff and erosion. Including belts of cover vegetation between crops is known as contour strip farming.
Contour Strip Mining: mining (mainly for coal) by slicing contour bands into a slope.
Conurbation: the fusion of growing metropolitan areas into a megalopolis. An intermediate stage in the development of what Lewis Mumford referred to as necropolis, an example of which is tenemented Rome around the time that the Western Empire fell. Necropolis is the final stage in decadence, bureaucratic alienation, hatred of life, and urban implosion.
Convection: vertical heat transfer, as in a convection current.
Convectional Precipitation: when heat from the ground rises, cools, saturates the air, and falls, most often as rain from a highly localized storm. Common along the equator and deep inside continents.
Convergence: similarities that appear independently in more than one type of organism. (Animals that live in similar surroundings often resemble each other, for instance.) Contrast with Homology.
Convergent Evolution: the evolution of similar characteristics in widely separated populations. Wings in unrelated species of birds are an example.
Convergence Precipitation (Frontal Precipitation): formed when air masses collide, resulting in warm, moist air rising until it cools.
Conveyance Loss: water lost during transport. Evaporation from a creek, leakage from a pipe.
Coral: marine invertebrates that secret a calcium carbonate exoskeleton and live symbiotically with algae, with the algae providing nutrients like carbon and the coral nitrogen, phosphorous, and an abode. Corals are perforate (porous skeleton) or imperforate (solid skeleton). Colonial corals live in deep water, and reef-building corals in warm, shallow water where their zooxanthellae algae can receive sunlight. When corals die, their outer skeletons remain, growing the reefs layer upon layer (see Atoll). As of the second millennium, two fifths of the world’s coral had disappeared due to industrial pollution, and all of the remainder is under threat.
Coral Bleaching: where coral lose their colorful symbiotic algae. This happens when carbon dioxide (a greenhouse gas) enters the water, cutting down reef production and leaving existing reefs vulnerable to erosion.
Cord: a stack of wood with a gross volume of 128 cubic feet (4 feet by 4 feet by 8 feet).
Cordgrass: several plant species living in brackish or saline estuarine marshes; below them are tidal mud flats, and above them salt marshes. Cordgrass produces five to ten times as much nutriment and oxygen as a comparable acreage of wheat. Very useful for tidal marsh restoration because its roots hold the mud in place as the plants bracket incoming waves while filtering them for nutrients.
Cordon: horizontal branching of a grapevine clinging to a trellis.
Core: the Earth's iron-nickel interior; about 7,000 kilometers in diameter. Its currents generate the planet's magnetic field.
Core Aeration: taking plugs of soil out of the ground to increase its aeration. Roots die in overly compacted ground.
Coriolis Effect: the apparent deflection of an object in motion because of the Earth's rotation. Low pressure systems in the northern hemisphere turn counterclockwise (clockwise in the southern hemisphere). Think of the apparent curve caused by a child trying to walk a straight line from the center of a carrousel to the edge as it spins.
Corm: a short, thick stem that stores nutrients underground. Usually a monocot, it does this through hot summers or cold winters.
Cormel: a corm that grows around the parent corm. Planting it can grow a new plant.
Cotyledon: embryo or seed leaves. They store nutrients for the seed until it grows its own photosynthetic leaves.
Coulee: a deep, dry ravine or streambed. Also, steep flow of hardened lava.
Counter-Radiation: greenhouse deflection of incoming longwave radiation back to the planet surface.
Cover Crop: a crop grown to protect the soil from erosion and nearby food crops from weeds. Can be dug under to put nutrients back into the ground. Common cover crops include buckwheat, hairy vetch, Austrian winter pea, and various clovers.
Crash: a sudden population dropoff caused by resource depletion. See Dieback.
Craton: the stable foundation of the continental plates; composed of the shield and platform.
Creep: slow downslope soil movement.
Cross-Bedding: sedimentary beds tilted when deposited in the direction the water or wind that built them was moving.
Crown: where the plant root joins the stem.
Crown Cover: the percentage of forest floor overgrown with tree crown. A major component of forest productivity. Lack of light and room to grow limits it (called crown shyness).
Crash: sudden depopulation as a result of resource depletion. A crash can often be seen a long way off in communities on a direct course to disaster through overuse of food and other vital supplies.
Creationism (renamed Intelligent Design): the use of scientific-sounding arguments to “prove” an unquestioned belief that a God created the world, usually in a short period of time. Creationism is a "working against nature" rather than a "working with nature" enterprise in its insistence that the divine stands apart from the natural in a relationship of domination (supernaturalism). Few scientists take Creationist claims of worldwide Biblical floods and inexplicable gaps in the fossil record seriously. In 1961 Henry M. Morris (1918-) and John C. Whitcomb, Jr. published a poorly researched book called The Genesis Flood that added nothing scientific to the argument but did inspire the formation of a Creation Research Society in 1963. See Evolution.
Cryosphere: the part of the Earth that remains below the freezing point (e.g., the poles).
Cryostatic Pressure: ice pressure of the kind often seen inside glaciers.
Cryoturbation: frost churning of soils.
Cryptophyte: a plant whose reproductive organs (e.g., bulbs, corms) are underground or underwater.
Cultivar: an organism with desirable breeding qualities.
Cultivate: to break up soil in preparation for planting. Firing, clearing, plowing, and cultivating destroy the colloids that hold soil together and trap nutrients.
Cuspate Foreland (Ness): a triangular shingle of particles at points located between joined ridge deposits along a coastline. Similar to sand spits, but wider.
Cuticle: a waxy layer of cutin that protects the surfaces of leaves.
Cuttings: segments cut from parent plants for growing elsewhere. Cuttings grow best from sunside shoots or branches with two nodes each. They are planted with the top bud just clear of the soil.
Cyanobacteria: bacteria that photosynthesize. They were among the first living things on Earth. The food-making chloroplast of plants is actually a cynobacterium imported long ago.
Cyclone: a low-pressure center wrapped in rotating movements of air.
Cyst: a capsule-like sac that encloses a spore, parasite, or abnormal growth.
Cytokinesis: cell division.
Cytoplasm: the portion of a cell's protoplasm (living matter) outside the nucleus.
Damping Off: a common fungal disease that wilts seedlings and rots stems. It can often be avoided by holding off on mulching until the seeds have sprouted.
Darwin Awards: "The Darwin Awards salute the improvement of the human genome by honoring those who accidentally kill themselves in really stupid ways." Fair enough, but the biologically pertinent question is: do they do so before, or after, they pass on their genes?
Days to Maturity: the number of days between planting the seed and first harvest. In politics, the end of the current geological age.
Deadhead: to remove spent blossoms in order to encourage new flowers. Also, avid if heavy-lidded collectors of Jerry Garcia T-shirts, skeleton costumes, handmade jewelry, and hemp.
Declination and Right Ascension: declination, the angular distance north or south from the celestial equator (the imaginary sky curve projected upward from the Earth's equator), combines with right ascension (measurement along hour circles circling like meridians between the celestial poles) to plot sky objects in a grid similar to that of longitude and latitude. Because the Earth spins in space, right ascension is measured in time intervals rather than degrees of arc.
Deciduous: annual or seasonal shedding of foliage from trees and shrubs. Conserves water by cutting down on transpiration and nutrients by reducing what the leaves required. Deciduous trees are useful in gardens because they give shade in summer, let in light in winter, and drop leaves that enrich the soil when decomposed. They are best transplanted when dormant (late autumn to early spring).
Decomposer: an organism that eats dead organic matter. Most are bacteria, algae, and fungi. They fuel the nitrogen and oxygen cycles that support all life on Earth.
Deep Ecology: a term coined by Arne Naess in his 1973 article “The Shallow and the Deep, Long-Range Ecology Movements” to challenge the exclusively human-centered view of the natural world by looking more deeply into questions of our place in it (as opposed to surface environmental reform that addresses problems but not their psychological or philosophical underpinnings). Its two fundamental norms, irreducible to any others: self-realization (as opposed to ego-realization) and biocentric equality that opposes anthropocentrism as the heart of our problem with nature. Naess’s motto: “Simple in means, rich in ends.” After working out a philosophical platform with George Sessions while camping in Death Valley in 1984, Naess later defined “deep” in terms of a persistent questioning (problematizing) and a pursuit of deep (significant) change. Deep ecologists see identification--with plants and animals, places, the world--as the basis of empathy and relationship. (David Kidner prefers “resonance” between self and other to "identification.") Warwick Fox believes that unlike social ecology and ecofeminism, deep ecology moves the source of our war against nature from intraspecies (human) to interspecies, a move that transcends blaming politicians or industrialists by focusing on their justification: anthropocentrism, which lovelessly regards the world as a thing for human use.
Deflation: the removal of soil by wind erosion in hollows and depressions.
Defoliant: an herbicide that kills leaves.
Degrading Use: water contaminated before it can reenter the hydrological cycle.
Deme: an interbreeding subpopulation.
Demersal: a bottom-feeding animal.
Demographic Transition: the hypothesis that industrializing nations exhibit death rate declines followed by birth rate declines.
Dendrochronology: dating a tree by counting its rings.
Denitrification: chemical conversion of dissolved nitrogen (nitrite) into gaseous nitrogen. Fires on particular soils do this.
Density Current: when a denser current sinks down under a less dense current and flows along the bottom.
Density Dependence: the tendency of a population's growth rate to depend on its size, with an increase in population density corresponding to a decrease in growth. This self-regulating dynamic helps prevent extinction.
Dependent Co-Arising (Paticca Samuppada): Buddhist theory of mutual causality, which in practice means the interdependency of personal and social activity. Joanna Macy links this to a sense of environmental responsibility: consciousness (not ego) and world rise and fall together.
Deposit Feeder: a bottom-feeder that eats sedimentary material and by doing so stirs up the mud.
Deposition: the dropping of transported particles out of moving water onto a resting place. Also, a transformation from gas to solid as a result of cooling.
Depression: a low pressure system.
Desalinization Plant: a site where seawater is boiled to separate steam from salt; the steam condenses into fresh water. Because this requires a large amount of energy--normally provided by burning coal or oil--desalinization is normally used only in very dry areas.
Desertification: the degradation of moist land into a desert. Some desertification is natural, but most is from erosion, climate change (global warming), or overgrazing.
Detritus: decomposing organic matter (leaves, bugs, etc.).
Detritivore: an organism that eats detritus.
Dew Point: the temperature at which water vapor from a saturated air mass turns into liquid. Below freezing, called a frost point.
Diagenesis: changes to sediment or fossils after burial. Similar to metamorphosis, but with less depth and less heat.
Diapsid: a vertebrate whose skull has two pairs of side openings behind the eyes, e.g., lizards, crocodiles, snakes, dinosaurs.
Diatomite (Diatomaceous Earth): a sediment formed from diatoms (unicellular algae with yellow chloroplasts).
Dicot (Dicotyledon): flowering plants whose embryos have two cotyledons (seed leaves).
Dieback: the deep population crash when an environment can no longer support a population's demands. Usually leads to dieoff (extinction).
The facts of nature cannot in the long run be violated. Penetrating and seeping through everything like water, they will undermine any system that fails to take account of them, and sooner or later they will bring about its downfall. -- C. G. Jung
Dioecious: plants with either male or female flowers, but not both (spinach, holly, date palm, etc.).
Dioxin: a highly toxic chlorinated hydrocarbon used in herbicides and produced by industrial pollution.
Diploid: a cell containing two sets of chromosomes. See Haploid.
Disaccharides: sugars composed of monosaccharides (simple sugars). Examples: sucrose and lactose.
Disjunct: the distribution of a species whose populations have been geographically divided.
Dissolved Organic Matter (DOM)(Dissolved Organic Carbon): decomposing carbon compounds in water. Can be natural or artificial.
Distributary: a branching stream channel that flows away from a main stream channel. See Tributary.
Diurnal: active by day.
Diurnal Tide: a tide that comes in once a day.
Divergent Evolution: when two populations become more and more dissimilar, usually as a result of different environmental pressures. The opposite of Convergent Evolution.
DNA (Deoxyribonucleic Acid): a form of nucleic acid organized into pairs of double-helix molecules packaged into chromosomes carrying the genetic code. The molecules are made of linked nucleotides: units with a sugar, a phosphate, and one of four base chemicals: adenine, thymine, guanine, and cytosine. These bases join like ladder rungs--always an A to a T and a C to a G--with the sugar-phosphate forming the outside "backbone" of the strand. The sequence of these nucleotides, with each group of three spelling one anino acid "codon," determines the kind of protein manufactured when translated by strands of RNA. (James Watson and Francis Crick discovered this structure in 1953.) RNA also aids in DNA's replication. Everything living carries the same gene code, one reason scientists are so confident we are all related biologically. Some DNA sequences are identical in humans and bacteria, a fact that underlines our common biological origins. See RNA, Chromosome.
Dockage: chaff, stems, and other such nonproductive plant residue that can be removed from a crop of wheat with a sieve.
Dogs: all are descended from Canis lupus, the gray wolf. Coyotes are the next closest relatives.
Dollo's Law: evolution never reverses itself.
Dormancy: a period of summer or winter metabolic slowdown in animals, plants, or seeds that need to conserve energy in inhospitable seasons.
Double-Digging: digging soil to a certain depth--12 inches, say, and in rows--and loosening the soil to a certain depth (often another 12 inches) below that before filling back in. Used to prepare soil beds where plants have not been grown. See French Intensive.
Downers: meat packing term for disabled or injured animals.
Drawdown: dropping water levels in a dam or reservoir. Also: the overuse of resources faster than they can be replaced. See Oil.
Dredging: scooping out a channel bed to prevent accumulated silt from stopping ship traffic.
Dry Farming: irrigationless farming in arid or semi-arid conditions (rainfall below 20 inches a year).
Dualism: the perceived split between people and nature normally traced back to French philosopher Rene Descartes but with roots in monotheism, Plato, and still older sources. Val Plumwood has named five features that characterize dualism: backgrounding, radical exclusion, incorporation, instrumentalism, and homogenization.
Dunes: along with estuaries they prevent coastal flooding and erosion.
Dust Dome: brown or gray dome of air particles and pollutants trapped by an urban heat island above a city. The meteorological equivalent of the Metrodome.
Drumlin: an elongated hill of glacial till or drift whose narrow end points toward the retreating glacier.
Dykes: vertical veins of igneous rock formed by magma cooling in breaks and fractures.
Dynamic Metamorphism: metamorphism that changes a rock's shape without changing it chemically. Sometimes associated with mountain-building.
Dystrophic: toxic habitats deficient in nutrients.
Earth, Age Of: 4.55 billion years. Formed by particles of gas and denser materials once ejected from exploding supernovae and gradually pulled together by gravity.
Earth Day: a planetwide celebration of our home that started on April 22, 1970 with a "Teach-In" organized by Gaylord Nelson to bring greater awareness to environmental concerns. It spread spontaneously to thousands of campuses and involved at least 20 million participants. Earth Day has become popular enough that politicians and corporate heads have started giving speeches on April 22. (President Bush tried it in 2005, but the Great Smoky Mountains thundered and rained him out. See Animism.)
Ecesis: the establishment of a plant or animal species in a new environment.
Ecliptic: the apparent circular path of the sun around the Earth as seen from the ground.
Ecocentric: term coined by Warwick Fox in preference to biocentric (environment-centered). Both contrast with the more human-focused perspective prevalent in industrialized nations.
Ecodynamics, Laws Of: formulated by philosopher Edward Goldsmith as corrections to the reductive laws of thermodynamics. The Laws postulate that living things seek to preserve their structure, grow toward climax (maturity) rather than entropy (nonexistence), move into mutualism and wholeness, and survive and flourish through spontaneous, adaptive self-regulation.
Ecofeminism: term introduced (“ecofeminisme”) by Francois d’Eaubonne in the 1974 text Le Feminisme ou la Mort. Dissatisfied with ecological analyses that leave patriarchy out of account, ecofeminists out parallels between how men in the West mistreat women and how they mistreat the Earth: in both cases a relationship of power, control, a will to dominate, and a pervasive fear of of the fact of interdependency. A twist on this is the patriarchal habit of objectifying women while feminizing the environment; women are then seen as less mature or human because "closer to nature." Not all ecofeminists agree on women's relationship to the natural world: Salleh thinks that feminine bodily experiences situate women more closely to nature, whereas Roach critiques this for reinforcing of the old nature-culture dichotomy. Many ecofeminists have criticized deep ecology's emphasis on unity (seen as a deemphasis on diversity and particularity) and on the need for elaborate philosophizing; for Plumwood, who sees the Western exaltation of rationality as a suicidal expression of ecological contempt, "identifying" with nature is an extended egotism that replaces relationship with psychological fusion. For Ynestra King, the tie with nature, though socially colored, should be celebrated rather than repudiated as "determinist" or "essentialist."
Ecological Efficiency: the percentage (usually around 10%) of useful energy that passes from one trophic level in a food chain to another. Shorter food chains tend to lose less energy.
Ecological Equivalents: species that live far apart but in similar niches and ecosystems.
Ecology: from the Greek oikos (household) and logos (study): the study of interrelationships between organisms and their environment. The term was coined in 1866 by German biologist and philosopher Ernest Haeckel, famous also for his discredited but interesting dictum that ontogeny (individual physical development) recapitulates phylogeny (the evolutionary development of its species).
Ecopsychology: a relatively new discipline operating on an ancient assumption: the deepest levels of the psyche are tied to the Earth (unlike environmental psychology, which looks in linear fashion at the impact of surround on psyche). Theodore Roszak, for instance, posits an “ecological unconscious” at the core of the psyche; Stephen Aizenstat describes a “world unconscious” similar to what early philosophers described as the anima mundi or world soul. As with deep ecology, ecopsychology insists that to be healthy, our relations with the Earth must be reciprocal, not exploitive. "Ecopsychology is the effort to understand, heal, and develop the psychological dimensions of the human-nature relationship (psychological, bio-social-spiritual) through connecting and reconnecting with natural processes in the web of life. At its core, ecopsychology suggests that there is a synergistic relation between planetary and personal well being; that the needs of the one are relevant to the other." -- Robert Greenway, Amy Lenzo, Gene Dilworth, Robert Worcester, Linda Buzzell-Saltzman.
Ecosophy: the philosophy of Deep Ecology.
Ecosophy T: Arne Naess’s brand of deep-ecological philosophy whose ultimate norm is Self-realization: realization of self and ecosphere and, ultimately, the universe. From this norm follow certain values like: interdependency of all things; maximum diversity; minimal exploitation; elimination of class society; maximum symbiosis. A key premise is that everything living has an intrinsic value apart from its purely human use value. The “T” recalls his hut Tvergastein, named after quartz crystals found nearby. (One of Naess's models, Spinoza, was a lens-grinder.) See Deep Ecology.
Ecosphere Share: the financially and politically dangerous idea that each person is entitled to a share of the world’s resources in accord with what's needed to live.
Ecosynthesis: Haikai Tane's term for a hypothesized evolution of ecosystems, some changing in response to human-caused planetary changes.
Ecosystem: a biotic community and its surroundings, part inorganic (abiotic) and part organic (biotic), the latter including producers, consumers, and decomposers. The term was introduced in 1935 by Sir Arthur Tansley. Social ecologist Murray Bookchin prefers the less mechanical word ecocommunity. Its components are not reducible to the interdependent relationships that emerge from it.
Ecosystem, Pulsing: Howard Odum's hypothesis that ecosystems change not only gradually, but in the unpredictable starts, fits, and "pulses" characteristic of systems subject to chaos dynamics.
Ecotage: term invented by future Environmental Action members at Earth Day, 1970, to describe the sabotage of environmentally harmful machineries (bulldozers, SUVs) and projects (housing tracts, supermalls). Similar to monkeywrenching (Edward Abbey’s term from his 1976 novel The Monkey Wrench Gang). Most greens consider ecotage inappropriate until, at the very least, actions like nonviolent resistance have proven futile. Dave Foreman of EarthFirst! distinguishes between terrorism (which is aimed at innocent people) and ecotage (aimed at devices that ruins ecosystems). Farmer-writer Gene Logsdon has wondered whether groups who resort to such acts ever think about protecting, say, vanishing topsoil.
Ecotherapy: Earth-based healing practices. "Ecotherapy involves understanding and healing the human-nature relationship through connecting and reconnecting with natural processes"(Robert Greenway). Ecotherapist Linda Buzzell-Saltzman refers to the field as "ecopsychology in action."
Ecotone: the transitial zone between adjacent biotic communities, often with unique nutrients and ecological relationships.
Ecotope (Biotope): the smallest ecologically distinctive area within a landscape classification system.
Ecotopia: a vision of an ecologically friendly society.
Ecotourism: tourism that makes use of the ecological attributes of a place (e.g., bird-watching).
Ecotype: a genetically differentiated subpopulation evolved to remain within its habitat.
Edaphic Factor: any organism-impacting feature of the soil, like pH for the plants there.
Edge Effect: the unique properties in an ecotone (plant variety, animal density, biological diversity), the zone where two communities meet.
Edge Wave: one that runs parallel to the shore.
Effluent: a substance (usually toxic) entering an environment from a point source (a confirmable location). Example: wastewater from a manufacturing plant (effluence from affluence).
Effusive Eruption: non-explosive flows of thin basalt-forming magma from a volcano. Often associated with shield volcanoes.
Elastic Limit: how much a rock or mineral can bend without shattering.
Elastic Rebound Theory: earthquakes happen when continental plates moving in opposite directions finally slip after a long accumulation of stress.
Elater: a structure that disperses spores when moistened.
Element: a molecule composed of one type of atom (e.g., Carbon, Hydrogen, Helium). At present the Periodic Table contains 112 elements. Two or more elements form a compound.
El Niño ("the boy"): a periodic climate change brought by warmer Pacific currents (as high as 14oC warmer) normally pushed away by the Pacific trade winds, which fade every three to seven years. As barometric pressure shifts over the Pacific and Indian Oceans (the Southern Oscillation), floods strike some regions (the West Coast of North America, for example) as droughts bake others (parts of South America). (South American fisherman bestowed the name because the effect--which lasts eight to ten months--often arrives near Christmas, birth time of the Christ Child.) See La Niña.
Elfin Forest: forest of small, scrubby trees sometimes draped with mosses or lichens; often found near a tree line.
Eluviation: movement of humus, chemical substances, and mineral particles from the upper layers of a soil to lower layers by the downward movement of water through the soil profile.
Embayment: portions of open water or marsh defined by natural topographical features such as points or islands, or by human structures such as dikes or channels.
Embryo: a zygote (fertilized egg) whose cells have divided prior to its developing into a foetus.
Emergent Wetlands: those whose vegetation partly above water and rooted below it.
Emissivity: the quantity of heat flowing from the Earth back into space. Emissivity and albedo help balance the global temperature.
Endocrine Disruptor: a pesticide chemical that interferes with hormones. It is suspected to cause vaginal cancer, immune system deficiencies, and birth defects.
Endoplasmic Reticulum: network of tubes and sacs involved with making protein (with ribosomes) and steroids and with storing calcium and glycogen (stored sugar).
Endosymbiosis: when one organism lives in another to the benefit of both. Examples of the resulting symbiosis include plastids, mitochondria, and chloroplasts.
English, Latinized: English evolved from the Anglo-Saxon tongues spoken by the Germanic tribes--Angli, Saxons, Frisians, Jutes--whose conscripts among the Roman legions had visited Britain (later, Angleland, or England) and found it inviting. They came around 410, the year Rome fell to the Visigoths and the Emperor Honorius decided from the safety of Ravenna that outposts like Britain were on their own. With the Romans gone, the incoming Germanics blended with the indigenous Celts, and so did their languages: into Old English and its earthy words ("dream," "water," "strong," "today," and "bread" derive from OE). So matters stood until William the Conqueror invaded in 1066 and brought along a language spoken at court: Anglo-Norman, a dialect of French nobilityspeak thick with Latin words transplanted from the Roman Empire and its warlike clerics. Eventually Anglo-Norman mixed with Old English to make Middle English (the language of Chaucer), but during the Renaissance, renewed interest in classical science and scholarship summoned another wave of Latinisms. With these and an infusion of Greek terms in place, English grew standardized with help from the printing press. Today only about one-sixth of it is homegrown, the rest imported from other languages. Surrounded by the cogs and wheels of the Industrial Revolution, capitalists and scientists coined more new words from Greek and Latin formations that lent themselves to abstraction, classification, and measurement. Hence the need for glossaries like this one. (For one more item, see Inkhorn.)
Enterococcus: an anaerobic bacterium with two strains that live in the intestines and others that cause infections to wounds and the urinary tract.
Entomophilous: seed plants pollinated by insects.
Entrainment: transport of organisms in moving water.
Entropy: disorder or unproductive energy in a given system. It tends to increase over time.
Enzyme: proteins that augment (catalyze) and manage chemical reactions in cells by lowering the activation energy.
Epibenthic: living on the surface of sediments lying on the floor of a body of water.
Epifauna: animals that live on a surface. See Infauna.
Epiphyte: a plant growing on, but not nourished by, another plant. See Hemiphyte.
Epithelium: the layer of cells lining a body cavity to protect it (e.g., the stomach). Both plants and animals have it.
Epizootic: impacting many animals at once, as with a disease outbreak.
Equilibrium Success Strategy: species that survive through low death rate, relatively little colonization or expansion, moderately frequent reproduction cycles, and other steady-state patterns of adaptation. Tends to be the larger animals. See Opportunistic Success Strategy.
Equinox: the two annual periods when the sun crosses over the earth's equator either north to south or south to north, thereby making a day and a night of equal length: an unusual circumstance given the planet's tilt. The spring (or vernal) equinox is on March 21 or 22, and the autumn equinox on September 22 or 23. In other terms: the two periods when the ecliptic crosses the celestial equator.
Erosion: some natural, but more and more due to human interference (development, urbanization, agricultural exhaustion of soil, etc.). In the U.S., over 140 million acres are classified as HEL ("highly erodible land").
Every time you see a dust cloud, or a muddy stream, a field scarred by erosion or a channel choked with silt, you are witnessing the passing of American democracy. -- Sterling North
Escarpment: a cliff-like ridge formed by faulting or erosion. It divides two more or less even pieces of land.
Esker: long rope and ridge deposits left by glacial melting.
Espalier: a plant trained to grow vertically, usually up a fence or trellis. Conserves space, heat for frost-prone areas; enhances productivity.
Estivation: similar to hiberation, but during the summer, underground.
Estuarine Zone: an estuary--a watery coastal conflux where tide meets river--plus the surrounding wetlands (intertidals, salt marshes, lagoons, bay mouths, etc.) Thick with nutrients and organic matter, such zones are the highest producers in the ecosphere. Eliminating one removes the grasses needed by local fish, shrimps, snails, and other protein-rich organisms, deprives the are of a pollutant scrubber, and removes a key flood-control device. With strong-arm help from the Army Corps of Engineers, about half of the estuaries in the U.S. have been destroyed by dredging and filling and other forms of “development.” 95% are gone in California. See Wetland.
Eukaryote: an organism with a membraned cell nucleus. See Prokaryote.
Eustacy: sea level changes due to seawater volume changes in the oceans.
Euphotic Zone: the zone of water penetrable by sunlight.
Eurybathic: able to tolerate different depths in water (like a sperm whale, which can ride on the surface or dive deeply). Contrast with Stenobathic.
Eurythermic: able to tolerate broad temperature changes.
Eutrophic: productive; applies to habitats rich in nutrients and organic material.
Eutrophication: a gradual nutrient enrichment that increases organic matter production, as with a lake that absorbs waves of nutrient runoffs.
Evaporation: liquid water's transformation into vapor. Requires a lot of energy.
Evapotranspiration (Transpiration): the evaporation of water off leaf surfaces. A natural event, but can cause plants to lose too much water in dry times.
Evenness: the even distribution of individuals of a species. Of two groups of plants, roughly 50 individuals in each group is fairly even; 2 in one group and 50 in the other would be uneven. See Richness.
Evergreens: trees that keep their foliage throughout the year. Needle-shaped leaves retain moisture with less loss to transpiration. Compare Deciduous.
Evolution: adaptive changes in the genetic characteristics of a population over time--but this adaptation is not necessarily “improvement.” This entry says "Evolution" and not "Evolutionary Theory" because evolution is not a theory anymore. Evolutionary operations and outcomes have been observed directly, today, as well as indirectly through field studies, DNA research, evidence-dating techniques, the fossil record, etc. The animal equipped with a new and helpful feature is likelier to live long enough to pass it down than an animal without it.
Elephants in China are more frequently born tuskless, now, due to pressure from poaching. See Speciation for an example of a family of Asian butterflies branching into different species today. Genetic mutations, which are rare and usually harmful, play less of a role in evolution than Darwin believed, and cultural forces that reinforce selection for certain characteristics a larger role. (See Natural Selection and Sexual Selection.) According to biologist Richard Dawkins, the eye has evolved independently at least forty times, echo location four times, the venomous sting ten times, electrolocation several times, flapping flight four times, jet propulsion twice, and sound production for social puroses too many times to count. See Convergent Evolution, Taxonomy.
According to this chart, the highest form of life on Earth is the French poodle.
The walls between "nature" and "culture" begin to crumble as we enter a posthuman era. Darwinian insights force occidental people, often unwillingly, to acknowledge their literal kinship with critters. -- Gary Snyder
Exfoliation: the weathering off of granite sheets. Called unloading when it happens in conjunction with uplift.
Exogenic: external to the Earth.
Exon: the segment of the gene that codes proteins (not all segments do). Each exon codes for a specific part of the protein to be created. Not to be confused with Exxon, whose extra x symbolizes what it codes: dangerously unpredictable environmental hazards due to petroleum products burned or spilled into the biosphere.
Exotic Species: those not native to an ecosystem.
Explosive Eruption: common in composite and caldera volcanoes. Contrast with Effusive Eruption.
Extirpated: a species that no longer lives where it used to.
Facilitation Model of Succession: ecological succession is driven by pioneer species (often annuals) preparing the way for later (often perennial) species on and into the climax. See Succession.
Fecal Coliform Bacteria: unharmful enteric (intestinal) bacteria whose presence indicates harmful comtaminations.
Facultative: able to live in more than one kind of environment, like a plant that flourishes with or without air. Frequent in species that dwell in wetland uplands.
- Normal: the hanging wall (the fault that moves) slides down the foot wall (stationary).
- Reverse: the hanging wall slides up the foot wall.
- Strike-slip: the hanging wall moves sideways.
- Thrust: a reverse fault where the fault angle is 45° or less.
Fed Cattle: those ready for slaughter. Industrially warehoused beef cattle weigh about 1,100 pounds after the steady diet of protein and steroids they are forced to eat.
Feldspar: a group of common aluminum silicate minerals that contains potassium, sodium, barium, or calcium. Felspars are found in almost all crystalline rocks.
Felsic: light-colored minerals containing quartz and feldspar. Contrast with Mafic.
Fen: partially flooded low-lying peatland fed water from upslope. (Fen peat usually comes from decomposing sedges, rushes, and other such plant matter.)
Fermentation: the enzyme-controlled conversion of carbohydrates like grape sugar into hydrocarbons like alcohol.
Fetch: the stretch of open water in which wind can blow freely in one direction.
Field Capacity: the water remaining in a soil after it has drained naturally.
Filament: the piece stamen that positions the anther to disperse pollen.
Filter Feeder: an organism that screens its food from water. Baleen whales do this by forcing seawater past the baleen plates they use instead of teeth.
Fine Particulate Organic Matter (FPOM): organic matter which has undergone an initial decomposition.
Firn: snow compacted into glacier ice (firnification).
Firn Limit (Firn Line): the lower boundary a glacier's firn accumulation to have endured for one year.
First Law of Thermodynamics: energy cannot be created or destroyed, only converted into another form. Sunlight into tissue; motion into electricity.
Fissile: cleavable, like a rock that splits into parallel sheets.
Fixed: a genetic mutation that infiltrates 100% of a population.
Fjord: a long, usually narrow, inland-reaching coastal valley sculpted by a glacier.
Flocculation: the accumulation of particles into small masses that fall out of liquid suspension, usually to settle on the bottom. Salt does this with clay particles. It can also be used to separate contaminants from wastewater.
Flower: a plant's reproductive organs.
Floodplain: the natural path taken by a flood-swollen river. In the U.S., more than ten million homes are located in or near floodplains, and the Bush Administration has eased building restrictions in such locations. See Insurance.
Fluvial: pertaining to streams.
Fly Ash: powderlike soot particles produced by coal and oil factories. U.S. coal factories alone produce the better part of a hundred millions of tons of it per year.
Foliation: the metamorphic straightening of rock into parallel layers. Also: leaf formation.
Food Chain: the path of food energy transfer from green plants (primary producers) to grazers (primary consumers), omnivors and carnivores (secondary consumers), and to their predators (top carnivores). The detritus food chain starts when organic matter settles on the ground and breaks down. Because such linear food chains are relatively rare in nature, see Food Web.
Food Miles/Kilometers: term coined by Tim Lang to denote the distance food must travel from where it is grown or produced and where it is sold. Foods that must come a long distance often require more preservatives and generate more air pollution from the petroleum products used to ship them. For this reason food packaging does not usually say where something is grown. Buying from a local grower or farmer reduces or eliminates such environmentally unsound practices.
Food Web: the interconnection of all food chains in an ecosystem. Food web diagrams emphasize the circular complexity of feeding relationships.
Forb: a broad-leaved non-grass herb growing out in a field.
Forests: = rain. Cut down a forest and make a localized drought. Deforestation is a direct cause of spreading desertification worldwide. Parallel damage to the human psyche remains largely unexplored.
It was our Indian rule to keep our fields very sacred. We did not like to quarrel about our garden lands. One's title to a field once set up, no one ever thought of disputing it; for if one were selfish and quarrelsome, and tried to sieze land belonging to another, we thought some evil would come upon him....There is a story of a black bear who got into a pit that was not his own, and he had his mind taken away from him for doing so. -- Buffalo Bird Woman
Forest Outlier: a patch of forest separated from the main body.
Foraminifera: single-celled, shell-encased, microscopic protozoa found in all marine environments. Remains of their shells produces chalk.
Fossil Fuel: coal, oil and natural gas geologically transformed from ancient beds of plant matter into burnable hydrocarbons. All told, these industries put 800 tons of carbon dioxide into the air every second: a sobering number given that oxygen-breathing life on Earth depends on carbon remaining locked in the ground. Although none of these fuels carries much, if anything, left from the dinosaurs, these now-extinct saurons have come to symbolize them with an eerie persistence.
Founder Effect: a type of genetic drift in which the genes of founder organisms--those that move on from the population they came from--show up in their offspring more consistently than other gene combinations.
Fragmentation: breaking up of a forest into islands of trees.
Free-Living: a mobile organism that does not depend on other organisms for food or other resources.
Free Market: an economic system in which the wealthiest players are free to make as much money as they can regardless of consequences or catastrophes.
French Drain: a pipeless drain set in a buried channel of gravel to drain off excess water behind walls. Invented in Concord by Henry French.
French Intensive: a farming method developed just outside Paris involving raised, humus- and manure-rich beds over double-dug soil. Yields were very high compared to traditional agricultural methods.
Frequency Dependence: an interspecific equivalent of density-dependence in which a species grows when its population is low compared to another species and stops growing when the population is high. See Density Dependence, Predator Switching.
Freshet: a flow of fresh water.
Front: transition zone between air masses. Types include cold fronts (cold air pushing back warm air--often bringing stormy weather), warm fronts, stationary fronts, dry lines (air barriers separating moist from dry air--very common in the American Midwest), and occluded fronts (when a cold front catches up with a warm one; the resulting rotations of air can generate cyclones).
Frost: ice formation on exposed surfaces due to atmospheric cooling and a relative humidity of 100%.
Frost Creep: a gradual downslope movement of soil caused by repeated thawing and freezing.
Frost Wedging: the weathering caused by water freezing and therefore expanding in cracks and fissues.
Frugivore: an animal whose main diet is fruit. Many birds and bats are frugivores.
Fundamental Niche: for a given species, the ideal range of suitable conditions without competition or predators. See Realized Niche.
Fungi (Mycota): saprophytic (decay-fed), spore-making plants without chlorophyll: rusts, molds, smuts, mildews, mushrooms, and yeasts. Their long hyphae filaments aerate and bind soils, aid water transport, cycle nutrients, decompose organic matter, and allow roots to absorb nutrients from the ground.
Gaia Hypothesis: formulated by James Lovelock (1959) and further developed by Lynn Margulis, the scientific hypothesis that the Earth and its systems work as a self-regulating whole to maintain the biosphere through systemic feedback loops. The hypothesis was invented to answer the question of how certain environmental variables (gasses in the atmosphere, ocean salinity levels) that should be unstable remain in equilibrium.
Gallinaceous Guzzler: invented by Ben Galding, the term refers to covered, self-maintained watering containers or catchments fed by seasonal rains.
Gametes: eggs and sperm; reproductive cells that combine to form a zygote (fertilized egg).
Gametophyte: the phase when gametes appear in plants.
Gamma Diversity: regional diversity.
Gangamma’s Mandala: a symmetrical herb garden design that allows access without requiring any trampling on the garden beds.
Gap Dynamics: the ecological effect of a canopy gap opened when a tree dies or is otherwise removed from a section of forest.
Gause’s Principle (Competitive Exclusion): no two species in an ecosystem can permanently fill the same niche or use the same resources.
Gelifluction: the movement of soil over permafrost.
GEM: genetically engineered microorganism.
Genetic Drift: along with natural selection, a key evolutionary process, whereby the frequency of certain genes (alleles, actually) varies randomly in a given population rather than being "pushed" by natural selection. Think about a population of rats in which all but one have striped tails. A catastrophe kills all but the one, who goes on to breed. Result: a majority with unstriped tails.
Germ-Line Cells: those that specialize in reproduction.
Germ Plasm: the hereditary material in germ cells (e.g., genes).
Gene(s): a chunk of DNA that allows organisms to pass on adaptations and acquired features by making a protein through codon sequences. DNA duplication errors often create new genes. Gregor Mendel discovered genes and wrote about them--he called them "factors"--in 1865, but his work was ignored for 45 years. See DNA.
Gene Flow: the proliferation of alleles (different versions of the same gene) across populations.
Generalist: an organism able to survive under a wide range of environmental conditions.
Genetic Diversity: genetic variability found in a population due to the genetic combinations of its individuals.
Genome: the genes of a species. Their chromosomal order controls physical characteristics.
Genotype: an individual organism's genetic constitution. See Phenotype.
Geologic Time Scale: a scale that measures the vast amounts of time over which geological changes occur. Divided into eons, eras, periods, and epochs. We are now in the Phanerozoic Eon that started 543 million years ago when animals began to fossilize in large numbers, the Cenozoic Era (started 65 million years ago when the dinosaurs blew out), Quaternary Period (roughly 2 million years ago, when pre-humans appeared), Holocene Epoch (10,000 years ago, when the last Ice Age ended).
Geomorphic Threshold: the limit beyond which changes to a landform accelerate into a new state (e.g., a creeping slope suddenly falls over).
Geostrophic Winds: global winds; they blow above 1,000 meters up and are driven more by pressure/temperature factors than by surface features or conditions.
Geothermal Energy: heat energy from the Earth's interior. Geysers and volcanos are naturally occuring examples.
Gilgais: gentle depressions distributed fairly regularly across level landscapes of clay.
Girdling: wrapping something like wire around a tree trunk to choke the cambrium layer and kill the tree.
Gibbons: small apes that use their arms to swing from branch to branch.
Glacier: a more or less permanent body of ice compacted from recrystallized snow that expands or contracts depending on gravity and climate.
Glacial Milk: glacial meltwater cloudy with sediment.
Glacial Trough: a deep U-shaped valley formed by glacial erosion. Many contain cirques on the valley floor.
Glaciation: the modification of land features by glacier activity.
Glaze: an ice coating left by rain on a cold surface.
Gleization: when slowed decomposition in a waterlogged environment allows layers of vegetation to accumulate. Peat is a frequent result. In Russia gleization has been used to grow an organic "liner" to hold water in leaky ponds and dugouts.
Global Warming: the rising of the Earth's average global temperature because of greenhouse gases accumulating in the atmosphere. The scientific emphasis has swung from whether global warming exists to how to minimize the damage it will cause. One example of many: according to the British Antarctic Survey and U.S. Geological Survey as of 5005, 87% of 244 glaciers studied have retreated over the last fifty years, and average retreat rates are accelerating. If the Greenland ice sheet melts, sea levels worldwide will rise twenty feet. See Greenhouse Effect.
The tide rises in Tuvalu, but unnaturally high tides are not seen only
in the Pacific. They are being spotted now all over the world.
Glober's Rule: more heavily pigmented warm-blooded animals tend to be found nearer the equator.
Glucose: a simple six-carbon sugar produced by photosynthesis. An energy source for both plants and animals; it breaks down from ingested carbohydrates. Cellulose and chitin contain it.
Glycolysis: the breakdown of glucose via enzymes into pyruvic acid, an initial step in the conversion of simple sugars into energy for the body. See Carbohydrate Catabolism.
GM: acronym for genetically modified food crops. Most Americans do not realize that eating processed food almost always means eating something genetically altered, in part because the foods are not normally labelled as such.
Gneiss: a coarse, metamorphosed, foliated (laminated) rock in which feldspars and quartz, sometimes hornblende and mica, run in bands.
Golgi Apparatus: a cell organelle that wraps proteins in vesicle packages for shipment outside the cell.
Graben Fault: a subsided block of rock surrounded on two sides by faults. Similar to rift valleys.
Gradation: the growth and decline of a population. Also a geology term for land leveling by deposition and erosion.
Grafting: joining one plant segment (the scion) to another (the stock: a root or an entire plant) so they grow together. Used as an alternative from growing a plant from seed. Grafting produces many hybrids.
Grain: a type of simple dry fruit that does not open at maturity (technically called a caryopsis). See Cereal. Global warming is believed to have cut world grain production by 93 million tons in 2003 alone.
Granite: medium to coarse igneous rock congealed from felsic (light-colored) magma roiling under continents. Rich in quartz and potassium feldspar (orthoclase).
Granivory: loss of seeds to hungry marauders (e.g., birds).
Graupel: snow crystals fused with raindrops.
Great Leap Forward: Jared Diamond's name for the human artifacts, ornaments, paintings, and other symbolic innovations that appeared rather suddenly 40,000 years ago.
Green Algae: a common (more than 7,000 species) algae, especially in estuaries, with nucleated cells and chloroplasts that make food from sunlight. The "higher" plants evolved from it.
Green Manure: a crop grown to be dug into soil in need of nutrients. It is usually applied before the second crop (usually a food crop) grows to avoid overheating it or depriving it of nutrients.
Greenhouse Effect: the gradual warming of a planet by an atmosphere's conversion of incoming solar radiation into heat (discovered in 1824 by Jean Baptiste Fourier). This natural effect is amplified by growing quantities of greenhouse gasses--carbon dioxide, nitroux oxide, chlorofluorocarbons (CFCs), ozone, and methane--that trap reflected radiant energy as it tries to leave the planet. Some would see a tragic, bitter irony in using up topsoil, polluting the rivers and oceans, and blackening the atmosphere while unconsciously converting the entire world into a giant greenhouse. See Global Warming.
Green Psychology: see Ecopsychology. Ralph Metzner prefers the term "green psychology" because instead of sounding like yet another discipline or departmental specialty, it refers to what psychology should have been doing all along: visualizing human beings in our ecological context. In his book by the same name he notes, "The absence of any consideration given to the ecological basis of human life in textbooks and theories of psychology is startling: it's as if we lived in a vacuum or space capsule."
Green Revolution: a modernization of high-yield agriculture which began in 1944 in Mexico with the Cooperative Wheat Research and Production Program organized by the Rockefeller Foundation and the Mexican government under agriculturalist Norman Borlaug. The resulting production techniques boosted wheat yield enormously, and their use in India and Pakistan saved millions of lives. But because such production depends on irrigation (which invites salt), heavy machinery (which compacts soil), and chemical fertilizers and pesticides made from petroleum products, the long-term ecological consequences have been devastating.
Greensand: an organic source of potassium: 7% potash plus trace elements.
Greenwashing: the political or business practice of masking an environmentally destructive activity by promoting it as environmentally beneficial ("Healthy Forests Initiative") or, at worst, minimally damaging (e.g., the Bush Administration's argument that oil drilling operations in Alaska will only take up a few thousand square miles of the immense Arctic National Wildlife Refuge--which is like claiming that a man spraying toxic fumes into the air all around him takes up only the few inches on which his feet touch the ground).
Gross domestic product (GDP) -- Gross domestic product is a measure of the total production and consumption of goods and services in the United States. Because it does not take resource depletion or pollution into account, the GDP gives a false picture of the wealth of nations.
Gross Primary Production: the total amount of energy and nutrients transformed by plants into biomass or chemical energy (roughly 1-3% efficiency for photosynthesis and .2% for the ecosphere as a whole).
Group Selection: the controversial idea that instead of responding only to challenges that presently face an organism, natural selection encourages improvements that will eventually benefit a group. This would lend evolution a forward-looking or "teleological" capacity most Darwinians reject.
Growing Season: traditionally, the period between the last freeze in the spring and the first frost in the fall. Varies by location.
Grub: a thick, wormy beetle larva. Gardeners work diatomaceous soil into the earth in spring to keep grubs from eating plant roots.
Guild: a group of species that fill similar ecological niches (e.g., birds that eat bugs from tree bark), but separated by time or geography so they don't compete. Also: a permaculture term for harmonious plant assemblies gathered around a central element. Planted around an orange tree: rue and lavender to repel pests, nasturtiums to smother weeds and grasses, clover and vetch for nitrogen, and an albizia tree to attract ladybirds to eat aphids. The guild is a version of companion planting.
Gust Front: the blustery front edge of a thunderstorm. It separates warm surface air currents from cold downdrafts.
Gymnosperm: a plant (e.g., a conifer) that bears naked seeds. See Angiosperm.
Gypsum: pale, sedimentary rock (hydrated calcium sulphate) ground up for use in plasters, cement, and fertilizers.
Gyre: a spiral or rotational movement, like a circular air or water current.
Habitat: the abode of a species. (Microhabitat: of an individual organism.)
Halocline: a vertical water gradient where salinity changes steeply.
Half-Life: time required for half of a quantity of particle-emitting material to undergo radioactive decay. Because emission slows as the isotope decreases in radioactivity, taking half the life of its decay is more meaningful than trying to estimate the entire amount. Half-lives range from millionths of a second to millions of years.
Halophyte: a plant that likes saline soil (cordgrass, rushes, pickleweed). Most plants need less salty soil to grow in.
Hamada: a flat exposure of desert bedrock.
Haploid: a cell that contains only one set of chromosomes. Example: gametes (sex cells). By contrast, most of the cells that make up the body are diploid: they contain chromosomes from both biological parents.
Haplotype: a chunk of DNA that moves down the generations as a single unit.
Hardening Off: moving flats of sprouting seedlings outdoors into the shade before finally planting them in the ground. Takes about two weeks.
Hardpan: a hardened soil layer that blocks plant root growth. Caused by clay compation, iron precipitation, or cementing by calcium carbonate precipitates. Growing plants like dandelions can loosen it up.
Hard Technology: costly, highly centralized, mechanical technology that uses a lot of energy, wastes resources, and pollutes the environment. Mining and agricultural machinery, for example. See Soft Technology.
Hardwood: wood from angiosperm (flowering) trees; usually deciduous and broad-leafed (maples, cottonwood, ashe, oak, elm. See Softwood.
Hatching Asynchrony: when birds of the same group of eggs hatch at different times because the mother incubated some before laying the entire clutch.
Headland: a strip of land that juts seaward, usually with a cliff adjacent. Called a promontory when high and narrow.
Headwaters: the higher end of a stream's drainage.
Healthy Planet Food Pyramid: Lawrence Buzzell-Saltzman's model of sustainable consumption of local food. Focusing on where we get our food, the pyramid rests on three levels: first, from a neighborhood garden; next, from local organic farmers; and last, imported from elsewhere, a costly choice given the amount of fuel and preservatives required. The average load of food must now travel 1,700 miles: an extravagance in terms of energy and planetary health.
Heath: an open, coarsely soiled, poorly drained patch of land, usually acidic, supporting shrubs and small trees; similar to a moor, but less moist.
Heave: the partial levering of a plant up from soil alternately frozen and thawed.
Heavy Metals: elements between lead and copper in terms of the Periodic Table. Too much lead, zinc, nickel, mercury, arsenic, copper, or cadmium in soil can damage plants.
Hectare: 2.47 acres. See Acre.
Heeling In: temporarily covering the roots of dormant plants with soil or mulch to protect them from the weather.
HEL: see Erosion.
Helophyte: a cryptophyte (a plant whose reproductive organs are underground or underwater) that flourishes in water or waterlogged soil. Cattails, rushes, and reeds are helophytes.
Hemoglobin: the iron-bearing protein/pigment in red blood cells that tranports oxygen to the cells.
Herb: a nonwoody angiosperm whose flowers back seasonally. Herbs are grown for seasonings, for medicinal use, and for attracting beneficial insects like bees into gardens. They do best in at least six hours of sunlight daily and are harvested as the first flower buds open.
Herb Spiral: a spiral-shaped planting bed for herbs. It offers a more compact growing space and protects the plants inside it from weeds and wind.
Herbaceous: non-woody plants; herbs (graminoids, forbs and ferns).
Herbivores: organisms that eat plants. Insects are the most numerous herbivores.
Hemiphyte: an epiphyte (a plant that grows on another plant) that eventually extends its own roots into the ground.
Hetarchy: a non-hierarchical coordination of activity between species.
Heterotroph: an organism that cannot produce its own food and so must get it from other organisms. All fungi and animals are heterotrophs. See Autotroph.
Hibernation: an energy-conserving lowering of metabolism, respiration, heart rate, and body temperature while the body survives on accumulated fat supplies. See Estivation.
High Moor: a bog whose vegetation is low in nutrients.
Highwalls: the exposed, unexcavated cross-sections left by highwall strip mining of coal.
Holdfast: an anchor or "foot" used by an organism to stick to a surface.
Holding Pond: a pond or reservoir, usually made of earth, built to store polluted runoff.
Homeorrhesis: the correction of developmental defects before development is complete. A ten-dollar word for
Homogenization: gushing milk through a filter to spread out the fat globules into a mist (liposomes). This is done to keep cream from rising to the top. Homogenized milk is suspected by some of contributing to several health problems, including hardening of the arteries and diminished resistance to cancer.
Homology: a similarity shared by descendants of a common ancestor. We walk upright; so did early hominids.
Homosexuality: characteristic of roughly 10% of any population. Recent evidence suggests a genetic component. Those who argue that homosexuality is "unnatural" are apparently unaware of the behavior in birds, sheep, beetles, bats, penguins, dolphins, orcas, macaques, bonobos (some 75% of whom are thought to be bisexual), black swans, orangutans, and roughly 1,500 species.
Horst Fault: when two reverse faults push a block of rock upward between them. The opposite of a Graben Fault.
Horticulture: gardening; growing fruits, vegetables, and ornamental plans. Indigenous societies once believed on the brink of starvation until "civilized" by monoculturalists (e.g., the California Indians and the Spanish Mission System) are now known to have supported themselves with food grown horticulturally in mixed crops similar to those now studied by permaculture.
Hot Manure: manure high in nitrogen. Using too much can burn plant roots.
Hotbed: a bed of soil enclosed by a structure with a top of glass, and heated, often by manure, for raising seedlings.
Hox genes: those that determine what proteins go where in a developing body.
Humus: rich, black organic material; the living component of soils where plant and animal matter has been allowed to decompose. Ideal humus: 100 parts carbon, 10 parts nitrogen, 1 part phosphorous, 1 part sulfur. Most of the important micronutrients are cations; the most important anions are boron and molybdenum. Fertile soil contains 4-10% organic matter.
Hybrid: a cross between two genetically diverse parent plants. Agribusiness companies produce and sell hybrids that do not reproduce in order to retain a monopoly on seeds.
Any statistical justification of ugliness or violence is a revelation of stupidity. --Wendell Berry
Hydration: the chemical weathering of a mineral when water is added to it.
Hydraulic Despotism: having established control over all local irrigation, Egyptian and Babylonian rulers made water available for obedient subjects and shut it off for dissenters. Although Karl A. Wittfogel coined this term (1957) to apply only to Oriental despots, its practice is worldwide, as in the Los Angeles water wars of urban expansion and assimilation and Israel's diversion of the Jordan, a project that led to the Six Day War of 1967. The definition could be broadened to apply to enterprises like OPEC that monopolize vital resources.
Hydraulic Gradient: the slope down which underground water flows. It alters with changes in the water table.
Hydrocarbon: organic compound composed primarily of hydrogen and carbon atoms. Petroleum, natural gas, coal, and methane are examples.
Hydrologic Cycle: the ongoing transformation of water in the biosphere from ocean water evaporation to clouds, rain, groundwater and runoff, storage in organisms, etc. until its return to the oceans. The Earth holds roughly 326 cubic million miles of water, 97% of it in the oceans.
Hydrolysis: chemical weathering in which hydrogen ions from water alter a mineral's composition.
Hydroponics: growing plants without soil, usually by supplying nutrients to the roots by immersing them in a specially prepared solution or with special sprays (aeroponics).
Hydrosphere: the water mass of the earth, including water vapor. Oceans occupy 71% of the planet surface: roughly the same percent occupied by water in the human body. Of the fresh water in rivers, streams, reservoirs, etc., 90% is believed to show some level of pollution.
Hydrostatic Pressure: the push of water under pressure, as in an aquifer.
Hydrophyte: organisms that live in water habitats. Examples: water hyacinths and bald cypresses.
Hygrophyte: organisms that live in moist places (creeping spearworts).
Hygroscopic: able to absorb moisture, particularly from the air. Salt, glycerin, ethyl alcohol.
Hyperparasite: a parasite to another parasite. In crabs, pepper spot disease occurs when the flatworms that infect the crab are infected by a parasitic protozoan.
Hyphae: microscopic filaments from simple plants like mushrooms, bracket fungi, mushrooms, etc. that weave soil together.
Hypoxia: depletion of oxygen in water to less than 2 miligrams/liter. An excess of nutrients (eutrophication) from fertilizer runoffs, air pollution, sewage, soil erosion, and other sources can spark enough algal growth to deprive the water of oxygen and kill off fish and other organisms that need it.
Ice Wedge: wedge of ice whose expansions and contractions from melting and freezing open large cracks in the ground.
Igneous: a rock congealed from molten material beneath (intrusive) or at (extrusive) the Earth's surface. Granite is an intrusive igneous rock.
Illuviation: accumulation of soil materials (clay, humus, iron, etc.) leached from one soil layer or horizon into another.
Impervious Cover: a surface that blocks water from going into the soil: highways, streets, parking lots. In urban areas the resulting storm runoffs spread pollution and waste, erode whatever soils they reach, and threaten communities with flash flooding.
Impingement: power plant intake screen blockage by fish, weeds, or other water species.
Incipient Species: one about to become genetically isolated from its species of origin. See Speciation.
Indicator Plant: a plant whose presence and health give clues about soil quality. Moss sometimes means a lot of acid in the soil, for example, although to a seasoned eye, most plants can serve as indicators.
Indicator Species: a species that works like an indicator plant: its population and health reveal much about its ecosystem.
Infauna: animals that live in sedimentary deposits on the sea floor.
Influent: a plant or animal that has an important effect on the biotic balance in a community. Sometimes used to mean a species that moves into an ecosystem from outside.
Inhibition Model of Succession: small disturbances coupled with varying dispersal and longevity in a dominant species allow new species to gain a foothold in the ecosystem.
Inkhorn: a small ink container, but also a term of sarcasm directed at scholarly pedants who insisted on bringing long, Latinized terms--inkhorn terms--into English, a practice deplored in Shakespeare's day and even by Shakespeare. Thomas Wilson's rant appeared in 1553, his cry unheeded by generations of researchers who emulated a Latin-speaking priesthood by locking away their concepts in sacred verbal sacristies:
Among all other lessons this should first be learned, that wee never affect any straunge ynkehorne termes, but to speake as is commonly received: neither seeking to be over fine or yet living over-carelesse, using our speeche as most men doe, and ordering our wittes as the fewest have done. Some seeke so far for outlandish English, that they forget altogether their mothers language. And I dare sweare this, if some of their mothers were alive, thei were not able to tell what they say: and yet these fine English clerkes will say, they speake in their mother tongue, if a man should charge them for counterfeiting the Kings English.
Insolation: solar energy received by the Earth.
Insurance: what homeowners need when their homes have been constructed on slipping hillsides, canyon floors, eroding coastlines, floodplains, and swathes of chaparral by developers working in complete disregard of the forces and cycles of nature.
Integral Ecology: a perspective developed by Sean Esbjorn-Hargens and Michael Zimmerman to interfuse learnings from the various subfields of ecology with the integral teachings of Ken Wilber, those dealing with the All Quadrants/All Lines aspect in particular. According to integral theory, every phenomenon can be studied either individually or collectively, and from the inside or the outside. Integral ecology applies this by exploring the subjective, measurable, cultural, and developmental dimensions of a given ecological situation or problem rather than staying solely with one angle of attack.
Interaction: the primary ones are competition, mutualism, predation, parasitism, amensalism, and commensialism.
Interplanting: growing different crops close to each other, as with pole beans at the base of corn stalks, early peas followed by lettuce, and sweet corn with bush beans. When done properly interplanting provides a natural mulch or ground cover and inhibits pest infestations.
Interstem: a piece of stem grafted between the scion and the stock for improved root strength, bark, and flowers. See Grafting.
Intertidal: the stretch of shoreline between low and high tide.
Introns: parts of the gene that are never transcribed. See Exons.
Intuitive Totalization: the inflated habit of emphasizing connections between things without assessing whether the connections are relevant or important. A radioactive cloud drifting halfway around the world demonstrates an ecologically significant linkage between its point of origin and its destination; "everything is one" is verbal gas. ("Intuitive" because in terms of Jung's typology, such a blurring of sensate distinctions reveals an overexertion of the intuitive function, the psychic knack for sensing patterns, to the detriment of the grounding sensation function.) As Charles Manson liked to put it, "If all is one, then nothing is wrong."
Invertebrate: an animal without a backbone. Contrast Vertebrate.
Ion: an atom or group of atoms that carries either a positive (cation) or negative (anion) electrical charge because of having lost or gained an electron. Ions play a key role in many biochemical reactions.
Ionization: producing ions. Example: solar radiation striking the upper atmosphere.
Isobars: cartographic (but not actual) lines connecting places with the same average air pressure for a given period; used to define cyclones (low-pressure regions) and anticyclones (high-pressure regions).
Isogamy: where two individuals combine half their genes to make an individual offspring.
Isohyets: map lines connecting places with the same average precipitation for a given period.
Isostasy: the buoyancy of the Earth's crust (lithosphere) upon the asthenosphere. For a segment of crust, buoyancy depends on its thickness and density.
Isotherms: lines connecting places having the same average temperature for a given period.
Isotope (Nuclide): an element variant in which the number of neutrons does not equal the number of protons. U-235 has the same number of protons, but not neutrons, as U-238, but U-238 will not fission itself into an atomic chain reaction when lumped together.
Isothermal Layer: a vertical atmospheric layer where temperature remains uniform. Such layers form the bottom of the stratosphere, mesosphere, and thermosphere. See Atmosphere, Layers.
J-Curve: a curve on a graph that indicates an exponential increase: the curve begins low and angles upward rapidly. Worldwide population growth, for instance.
Jet Stream: a long, serpentine air current just below the tropopause (about 12 km up) and blowing westerly, generated by temperature differentials between air masses, and often exceeding a speed of 250 miles (402 kilometers) per hour. The two polar jet streams are the strongest.
Junk DNA: strips of DNA whose purposes have not been identified. They seem to play no role in anything genetic.
Kame Terrace: stratified alpine ridge deposited between a melting glacier and a valley slope.
Kangaroo Rat: an organism notable for its ability to make its own water.
Kaolinite (Aluminum Silicate Hydroxide): a clay produced by weathered feldspar. Common in clays everywhere, including China, where its name comes from. Used to make paint, rubber, ceramic, plastics, and the glossy stuff they put on magazines.
Karst: a limestone-bedrock landscape dotted by fissures, caverns, sink holes, and other evidences of chemical weathering.
Katabatic Wind: wind blowing down a mountain slope.
Kettle Hole: depression or pond found in glacial deposits (see Kame Terrace). Left by a chunk of melted glacier.
Kerogen: a solid, rubbery, waxy substance often found in shale. Under pressure it turns into a tarry hydrocarbon.
Keystone Species: a species that increases or decreases the diversity of a system. Example: otters, which when hunted to extinction remove a check on the sea urchins that will eat local kelp forests on which many other species depend.
Kinship Gardening: a form of companion planting in which botanical kin (taxonomically selected) are placed next to each other to foster mutual growth and health. Concept by Dr. Alan "Mushroom" Kapuler.
Krebs Cycle: the second stage in the breakdown of glucose (unprocessed sugar) into energy (ATP), carbon dioxide (as waste), and water Citric acid entering the Krebs cycle as a product of glycolysis (first stage) exits as NADH (reduced nicotinamide adenine dinucleotide), one molecule of GTP (guanosine triphosphate), and one molecule of FADH2 (reduced lavin adenine dinucleotide). NADH and FADH2 give their high-energy electrons to an electron transport system (third stage) that makes many ATP molecules. Named after German chemist Hans Krebs, who discovered the cycle in 1937. See Glycolysis, Carbohydrate Catabolism.
Krummholz: the twisty, shrubby islands of trees near a tree line (which marks the climatic boundary beyond which they will not grow).
K-Selection: species in stable environments tend to live longer and produce fewer, and sometimes larger, offspring. (K is the constant for carrying capacity in terms of population growth.) This used to be true for whales before their environment was changed. See R-Selection.
Labor-Saving Devices: “Without ‘labor saving’ technological gadgets to help me, I save a lot of time by not having to fix them.” -- Gene Logsdon
Lactose Intolerance: the inability to digest lactose, or milk sugar, due to insufficient lactase enzymes in the small intestine. Symptoms include bloating, stomach cramps, diarrhea, and nausea. People of Northern European descent tend to suffer it less because of an evolutionary transformation brought about by milk-drinking, a practice other humans have traditionally given up after infancy.
Lacustrine: a very fancy way of saying: having to do with lakes ("a lacustrine wetland"). See English, Latinized.
Lahar: a mud landslide that rushes down the side of a volcano and freezes into place like concrete.
- a littoral zone where shore plants grow
- an epilimnion, site of sunlight-driven photosynthesis
- a metalimnion below it, separating the upper waters from the
- hypolimnion, cool bottom waters, where organic decomposition occurs in the relative dark. Lakes with little oxygen at this layer but abundant green algae might be eutrophic (rich in nutrients but often poor in animal life), whereas clear lakes with surpluses of oxygen in the hypolimnion might be oligotrophic (poor in nutrients), with mesotrophic lakes somewhere in between.
Laminar Flow (Streamlined Flow): uninterrupted parallel flows of liquid, as with blood flowing smoothly through the circulatory system.
Land Breeze: surface air movement down a pressure gradient from land to water at night. The air over land is of higher pressure because the land, heated during the day, is warmer than the water. See Sea Breeze.
Land Systems Method: a mapping approach that integrates relatively uniform environmental features usually measured separately: rock type, climate, vegetation, soil, topography, etc.
La Niña ("the girl"): when tropical Pacific trade winds strengthen enough to pile cold water into the central and eastern Pacific. An intensification of normal conditions (in North America, stormy in the northwest and dry in the southwest). The opposite of an El Niño.
Larva: a recently born or hatched animal before it undergoes metamorphosis into its mature form.
Latent Heat Flux: the transformation of heat energy through cycles of air and water.
Lateralization: the specialization of brain functions by hemisphere (language in the left lobe, pattern recognition in the right).
Lateritization: the formation of laterite, an infertile red clay soil used for durable bricks in the tropic and subtropics, where rains and hot sunlight combine to wash minerals out of the soil before baking it dry. Triggers huge landslides in recently deforested areas.
Laterite: red or orange soil with insoluble concentrations of iron, aluminum, and other metals. Laterites rich in aluminium oxides are mined for their aluminium ore.
Lath House: a frame topped by strips of wood spaced to provide about 50% shade for crops like lettuce that need only partial sun exposure.
Latitude: a north-south measurement of position on the Earth, from the equator at 0° to the North Pole or South Pole at 90°. An east-west line connecting places of the same latitude is a parallel. Latitude is measured in degrees, minutes, and seconds. See Longitude.
Latitudinal Diversity Gradient: around the world, the diversity of species tends to increases as latitude decreases. In other words, life gets richer toward the equator and less so nearer the poles.
Lawn: one of the most wasteful things to do with fresh water. According to Bill Mollision (see Permaculture), cultivated lawns go back to the British Empire and the country estate, both in the business of taming the natural world. Their demand for water is second only to that of agricultural irrigation. Many require petroleum products to maintain and to fertilize, and pesticides to keep pristine despite their ecological vulnerability.
Leaching: the flushing or percolation of chemicals, minerals, or other substances through soil. Pesticides, fertilizers, poisons from mines or feedlots, and wastes from industrial plants sometimes leach into groundwater. Leaching also refers to washing the salt from soil to increase its fertility.
Leibig’s Law of the Minimum: each species in a community requires certain conditions to live, such that if any of them fall below a critical limit, the species cannot survive there.
Legume: a flowering bean or pea plant. All legumes contribute to the nitrogen, phosphorus (key to flowering and seed formation), and potassium nutrition of the crops that follow. Alfalfa is the heaviest nitrogen producer.
Lentic: still water (pond, lake, etc.); also, organisms living in it. Compare Lotic.
Levee: an embankment that works as a dike. Levees built to containn floods can actually accelerate floodwaters by narrowing natural channels.
Ley: arable land used occasionally as hay or pastureland.
Ley Farming: the rotation of legume and grain crops, developed as an alternative to crop-fallow practices in Australia. In addition to improved soils and reduced erosion, wheat yields increased 48% and showed a higher protein concentration.
Liana: a woody vine that climbs on trees to spread its leaves above the canopy. Used to make rattan.
Libidinal Politics: Ynestra King's term for politics grounded in care and relationships, in eros rather than logos only.
Lichen: the symbiotic association of a true fungi and a green alga. The alga makes sugar through photosynthesis, and the fungi fills out the organism while holding it to a surface (rocks, bark, etc.). Lichens pioneer harsh or sparse environments, provide food for grazers, and break down rocks through chemical weathering.
Life Pyramids: niche diagrams of the organisms living there.
Life Zones: created by C. Hart Merriam in 1894 to classify environments by temperature and rainfall. There are eight major life zones: Arctic-Alpine, Boreal (Hudsonian), Boreal (Canadian), Transition, Carolinian, Loouisianian, Upper Sonoran, and Lower Sonoran.
Lignite (Brown Coal): low-grade coal.
Limestone: sedimentary rock composed of calcium carbonate (calcium carbonate) formed by deposits of seashells and marine animal skeletons. Limestone is often added to cement and other construction materials, including blocks and facings.
Limiting Similarity: the degree to which niches must be different to avoid interspecies competition for them.
Limnetic: fresh water. (Limnology is the study of lakes and ponds.)
Lipids: fats, waxes, oils: greasy organic hydrocarbons insoluble in water. With proteins and carbohydrates, membrane-strengthening lipids provide cells with their structure.
Liquefaction: the brief conversion of saturated soil into a structureless mass that flows like fluid. When earthquakes trigger it, walls, dams, buildings, and foundations are liable to collapse. Frequent near coastal developments and areas of poor drainage.
Lithification: compaction and cementing of sediments into sedimentary rock.
Littoral: the shore between the high and low water marks. See Zonation.
Living Mulch: ground vegetation grown to shelter a crop from pests or weeds.
Loading: the rate at which something is added to water.
Loam: a fertile mixture of sand, silt, and clay in roughly equal parts.
Loess: silt deposited by the wind, often near glaciated land. Its erosion forms "cat steps" that slide off each other. A frequent component of fertile topsoil.
Longitude: an east-west measurement of position on the Earth. Measurements of longitude range from 0° at the Prime Meridian at Greenwich to + 180° West and - 180° East of it. A line connecting places of the same longitude is a meridian. It is measured in degrees, minutes, and seconds. Unlike latitude, longitude cannot take the poles and equator as fixed points of reference. It must rely more on time, which is why accurate long-voyage navigation had to await the invention of an accurate timepiece. See Latitude.
Longshore Current: one that moves parallel to the shoreline.
Lotic: flowing water, as in a river or stream. Compare Lentic.
Low Moor: a mineral-rich fen of peat or muck soil formed in nutritive waters, often drained from nearby.
Macroecology: the study of statistical distributions of large groups of organisms or species to see why the distribution patterns vary.
Macronutrients: soil nutrients (not including carbon, hydrogen, or oxygen) needed in relatively large amounts by plants: nitrogen, potassium, phosphorus, calcium, magnesium, sulfur. Soils lacking one or more of them are sometimes given amendments to add what's needed.
Macrophyte: a plant too large to be considered microscopic.
Mafic: dark-colored, igneous, and high in iron and magnesium and other heavy elements (as in gabbro and basalt). See Felsic.
Mad Cow Disease: bovine spongiform encephalopathy (BSE), a fatal, infectious disease that degenerates the central nervous system of cattle. It might have evolved from scrapie, a similar disease that infects sheep and goats. In Britain, the practice of feeding cattle with the remains of other cattle not known to have been infected helped spread the disease in the mid-1980s. (Given how the meat packing industry treats them anyway, no wonder the cows are mad.)
Magma: molten rock beneath the planet surface. (Lava is exposed magma.)
Magnetic Declination: the difference in angle between true north and magnetic north, or true south and magnetic south. The poles occasionally switch, also, which last happened 780,000 years ago.
Magnetosphere: the Earth's magnetic field, generated by the planet's nickel-iron core and extending thousands of kilometers into space. It shields the Earth from the highly charged plasma (mostly hydrogen particles) of the solar wind that emanates from the sun.
Maldevelopment: Vandana Shiva's term for what usually goes by the name of development and in actuality results in widespread poverty and ecological destruction. Maldevelopment contrasts with "realwealth," the actual richness and diversity of a community.
Why does progress so often look like destruction? -- John Steinbeck
Mammal: hairy, warm-blooded vertebrates that nourish their young with milk (hence the name). About 5,500 species in all, and all descended from a common ancestor of the anteater, platypus, marsupials like the kangaroo, and placentals. The extinction of the dinosaurs 65.5 million years ago made way for the growth of large mammals. 40% are rodents.
Mangrove: trees that grow in coastal wetlands in tropical climates. Their trunks block wind, and their roots provide habitats and a barrier to erosion.
Marble: metamorphic rock made of recrystallized calcite or dolomite. Limestone marble is white. Marbles like those played with on street corners were once made of marble; the common method of shooting one is called fulking (no kidding). It's considered impolite to fulk with another person's marbles without permission.
Maquis: dense, twisty, drought-resistant evergreen scrub growing in arid regions. Hiding behind it during World War II suggested a convenient name for the French underground.
Mariculture: growing and harvesting marine life. Compare Aquaculture.
Maritime Effect: an ocean's moderating effect on nearby climate. It tends to soften temperature extremes. See Continental Effect.
Marl: a light-gray earth made of carbonates from shells or fossils; can be either loose or firm. Used as a fertilizer or a source of lime for lime-poor soils.
Marsupial: a mammal whose offspring develop after birth in the mother’s pouch (the marsupium) outside her body. 75% of living marsupials come from Australia.
Marsh: a damp wetland less acidic and waterlogged than a bog.
Mass Extinction: a catastrophic reduction in species population. The mass extinction now underway threatens more than half the animals on Earth, some of whom have already vanished; others, like the great apes, are about to. For a tribute to what no longer lives, see the Altars of Extinction project online.
Mass Wasting: the gravity-driven (not water- or wind-driven) movement of rock or soil downslope. Tends to occur at higher elevations. Example: a landslide.
Matric Force: the attraction that holds water to soil particles. Contributes to soil cohesion and the formation of helpful colloids.
Matted-Row: placing plants off center or on a diagonal rather than in space-consuming rows.
Medfly (Ceratitis capitata): the Mediterranean fruit fly, one of the most destructive pests of deciduous fruits like pears, stone fruits, and apples. Its larvae also eat vegetables and nuts. Yellow-brown with reddish purple eyes. Chemical sprays do not control them effectively because of the brief time it takes the adult to lay eggs below the surface of the offspring's future food source. Braconid wasps and other parasites seem to do a more thorough job (see Biocontrol).
Megamachine: Lewis Mumford's term for a mechanical sequestering of human energy into rigid social hierarchies. His examples include the labor force that built the Pyramids and the armies of both World Wars.
Meiofauna: microscopic animals (nematodes, copepods, etc.) that live on the bottom of a lake or sea, usually between sand grains. The macrofauna (like fish) depend on them for food.
Meiosis: a two-stage type of cell division that creates gametes (sex cells). Because each must contain half a future offspring's DNA (one set from the father and one from the mother), the kind of cell division (mitosis) used elsewhere will not work--it would double the amount of DNA needed. To prevent this, meiosis turns a cell containing 46 chromosomes into four sex cells containing 23 chromosomes each (haploids) through an initial extra stage that mixes chromosomes. Aside from that stage, meiosis is like Mitosis.
Meme: a unit of cultural, as opposed to genetic, inheritance. Recent research supports Susan Blackmore's theory that the human brain evolved rapidly to make itself a better habitat for human memes. Such memes would be available for sexual selection.
Mercator Projection: a mapping system that favors nautical navigation over visual realism.
Meristem: plant cells that specialize in making new tissue. Different sorts of meristem make the various tissues (some for bark, some for leaves, etc.).
Merophytes: groups of cells that all originate from one cell. Merophytes build much of a plant, the leaves and stems in particular.
Mesocyclone: a spinning column of air inside a thunderstorm with a steep updraft. About half of mesocyclones spawn tornados.
Mesophytes: organisms living in habitats of moderate moisture.
Mesotrophic: moderately nutrient-rich habitats.
Metabolism: an organism's total biochemical activity. All the physical and chemical factors in the production (anabolism) and breakdown (catabolism) of protoplasm and energy. Also: all the enzymatic reactions that go on the cells. Metabolism is the fire of biological life.
Metamorphism: the transformation of a rock (called a protolith before the change) subjected to pressure, fluid, or heat into a different kind of rock. (Called prograde metamorphism when the change agents are intensifying, and retrograde when they are decreasing.) A frequent occurrence below the Earth's surface. Metamorphic rocks make up most of the planet's crust.
Metapopulation: local but geographically separated populations of a species that are linked only by organisms that migrate between them. Although local groups might die out, the migrants keep the species alive. (Term coined by Richard Levins, 1969.)
Mica: a mineral silicate whose hexagonal arrangements of atoms give it perfect cleavage (it breaks in sheets instead of fracturing or crumbling).
Microclimate: the climate of small locales: under plant leaves, in a garden, on a hillside. Can be used to offset too much heat, light, or cold in the surrounding area.
Microhabitat: a small, specific habitat, like under a log or in a bush.
Micronutrient: nutritional elements (e.g., copper, boron, manganese) required by a plant or animal in small quantities. See Macronutrient.
Mind-Body Problem: a sterile philosophical dilemma given its first modern expression by mathematician and swordsman Rene Descartes. Its basic question: how do the mind and the body relate to one another? Which implies that the two are as separate as self and world were thought to be (another Cartesian gem). A more profound philosopher spoke to this centuries before Descartes and his coordinate-plane approach:
When you wrack your brain trying to unify things without knowing that they are already one, it is called "three in the morning." What do I mean by "three in the morning?" A man who kept monkeys said to them, "You get three acorns in the morning and four in the evening." This made them all very angry. So he said, "How about four in the morning and three in the evening?"--and the monkeys were happy. -- Chuang Tzu
Mineral: the inorganic, crystalline solid that makes up rocks. Over 2,000 varieties have been discovered.
Mineralization: decomposition of organic matter into its inorganic (mineral) components (e.g., petrified wood). In archeology, the replacement of fossil bone with water-borne minerals.
Misanthropy: a hatred or distrust of humankind, as when people passing for environmental activists declare human beings a blight upon the planet. The implied dualism is older than Descartes.
Mitigation: promising to set aside a wetland to replace the one being built over.
Mitochondrion: an organelle (although outside the cell nucleus) that power the cell by converting organic matter into ATP (energy)--see Carbohydrate Catabolism. Mitochondria also regulate bodily heat and refine the oxygen that would otherwise poison us. They look like upturned pillbugs.
Mitosis: nuclear division, an initial step in cytokinesis (cell division).
Mixotroph: an organism that can double as an autotroph (produces its own food) or heterotroph (eats food produced by other organisms). Some tiny marine protozoans are mixotrophs.
Molecule: a group of atoms bonded together. Chemistry is the scientific study of molecular reactions.
Moment Magnitude Scale: developed in 1979 by Tom Hanks and Hiroo Kanamori to measure the total energy of an earthquake by considering the amount of fault slippage (the moment magnitude) rather than just the seismic graphing. The measurements are more physically precise than the Richter Scale it replaced. See Richter Scale.
Monoclimax Theory: in any environment, only one climax community will dominate. See Polyclimax Theory for a less capitalistic perspective.
Monocline: a fold in which rock strata bend in the same direction. Caused by sedimentary rocks bending over a fault line.
Monocot (Monocotyledon): flowering plants that have embryos with only one cotyledon (embryo leaf).
Monoculture: the cultivation of a single crop on a piece of land to the exclusion of other crops. This generally requires large quantities of artificial fertilizers, herbicides, pesticides, nematocides, and other potentiall toxic measures to kill bugs and increase yield. Even with these chemical aids, monocultures are prone to disease outbreaks and pest infestations. Wes Jackson (New Roots for Agriculture): agriculture leads to the monoculture of annuals, nature to the polyculture of perennials. Monoculture invites pests, diseases, erosion.
Much of the motivation for high yield in agriculture was in the “search for gold” realm and clearly is predicated on a form of conquest. -- Wes Jackson
Monoecious: a species with male and female flowers on the same plant (e.g., pines).
Monophagus: predators that favor a single prey species.
Monosaccharides: simple sugars.
Monsoon: a reversing seasonal wind often bearing heavy rainfall. Common near the Indian Ocean.
Moor: an open, uncultivated, grassy, often peaty tract of land with scrubby vegetation. Wetter than a heath but drier than a bog.
Mor: a layer of humus, particularly in a forest, whose chemical composition is distinct from the soil below it. Often acidic, cold, and rich in carbon content.
Morraine: a mound of earth or rock left by a glacier.
Morphology: the form and structure of plants and animals.
Mosses: small, leafy, spore-producing plants without true roots or water-conducting plumbing. About 9,500 species. They prefer dark, moist locations.
Moulin: a tunnel of water that forms when a lake on a sheet of ice begins to melt. The tunnel reaches downward until it spreads over the underlying bedrock. In the case of Greenland and Antartica, moulins are lubricating the remaining sheets of ice from below, making it easier for them to snap off and melt in the sea.
Mulch: a covering of detritus (leaves, stems, etc.) invented by plants to survive without weeding, watering, or fertilizing. Even compost is basically treated mulch. Mulching a garden reduces erosion, conserves soil moisture, inhibits weed growth, and provides the soil with organic matter.
Mutation: change in the structure of a gene or chromosome due to a biochemical replication error.
Mutualism: a relationship between species that benefits both. Can be symbiotic or nonsymbiotic.
Mycoplasma: parasitic bacteria that cause diseases (pneumonia). Similar to a virus.
Mycorrhizae: mutualistic association of a fungus with plant roots. The fungus is nourished and housed by the roots it transports soil nutrients into. Almost nothing green would grow without this symbiosis.
Natural Farming: Masanobu Fukuoka's method for letting roots till the soil instead of machines. Decrease cultivation and you decrease weeds. Leguminous cover crops and mulching instead of fertilizer. Fukuoka practices what he calls the "no-plowing, no-fertilizing, no-weeding, no-pesticides, do-nothing method of natural farming." To him the idea that people can grow crops is egocentric, for it is nature that grows crops. His rice yields have been impressive. (He reads like kind of a nut: lots of “man in his arrogance” soliloquizing reminiscent of Roger Payne in the seventies.)
Natural Gas: hydrocarbon gasses that accumulate in rocks of marine sediment. Roughly 80% methane.
Natural Selection: nature's selection of viable strengths through environmental pressures that force an organism to adapt. The bat that hears better than the rest stands a better chance of living long enough to pass on that kind of hearing. In this way certain favorable genes--favorable to adapting to environment pressures--gradually become more numerous in a given population. Discovered by Charles Darwin and Alfred Russel Wallace in 1858 (rather, discovered years earlier by both; Darwin beat Wallace to the press in 1858). Whether the environment shapes completely passive life-material or interacts with an emerging and ever-more-conscious creative potentiality is a most interesting current debate. See Evolution.
Natural Systems Agriculture: an approach developed by Wes Jackson and the The Land Institute that emphasizes mimicking natural ecosystems by growing perennial polycultures or mixtures of perennial grains, as prairies do.
Neap Tide: one that arrives when the moon is in its first or last quarter. Because the sun and moon stand at right angles to each other, their tidal pulls partially nullify each other, resulting in a lesser tide. Contrast with Spring Tide.
Nektons: aquatic organisms (fish, for example) that can swim against the current, whereas plankton drift with it.
Nematodes: microscopic cylindrical roundworms living in water and soil. Can be parasitic (as with the trichina and the hookworm) or free-living.
Neoteny: retention of juvenile characteristics in an adult, as in the axolotl salamander near Mexico City; under certain environmental conditions it never fully matures. See Progenesis.
Neuron: a nerve cell that transmits electrochemical impulses. Neurons were thought to work somewhat like electric switches: when triggered at the dendrite end by an incoming nerve pulse, they generate a pulse down the axon (with help from the Nodes of Ranvier, which work like signal boosters) to the terminal button, where the pulse triggers the release of neurotransmitter chemicals into the synpase, the space between one neuron and another. These chemicals then trigger a pulse (or inhibit one) in other neurons. As it turns out, however, each neuron is more like a microchip than a simple switch. At any moment only abut 5-10% of the human brain's neurons are sparking, but eventually they all do, a fact that contradicts the common but inaccurate idea that people use only a small portion of their brains. (How much of the brain a person uses at once, or regularly, is another matter.) The adult brain contains about 10 billion neurons, with the brain as a whole drawing 20-40 watts of power, and with an ultimate storage capacity of (very roughly) 100 terrabytes: about the same as every book ever written, digitized. It's hard to estimate because each dendrite contacts about 10,000 other neurons in extraordinarily complicated neural nets.
Neurotoxin: a poison that disrupts nerve function. Some venoms are neurotoxins that paralyze the prey.
Neutralism: hypothesized situation in which two populations have no effect on each other at all. Rare and unlikely. (To take a leaf from George Carlin's book, this is one of those ideas like walking up to someone, declaring, "I have nothing to say to you," and walking away.)
Neutron: a chargless particle in the nucleus of an atom. Neutrons and protons make up most of the atom's mass.
Niche: an organism’s role, function, or position in an ecosystem.
Niche Differences: those that keep organisms from competing for resources (like plants that draw nutrients from different depths).
Nickpoint: elevation drop along a stream. Falls occur at nickpoints.
Nitrate: a salt or ester (acid-alcohol product) of nitric acid; in soil, used by plants for building amino acids and proteins. Artificially manufactured nitrates are used in fertilizers and explosives.
Nitrogen Cycle (or Nitrification): cycling of nitrogen from the air and soil to plants, animals, and then back to the environment. Bacteria, legumes, and algae convert atmospheric nitrogen into nitrates that enter plant roots before turning into protoplasm that decomposers eventually break down again.
Nivation: erosion by frost or snow.
Node: the point on a stem from where new stem or leaves grow.
Nondegradable Pollutants: those that do not decompose. Examples include lead, mercury, arsenic, plastics, and synthetics.
Nonpoint Source (NPS): diffuse pollution whose source is difficult to determine (like polluted runoff).
Nonrenewable Resource: one that can be used up, like coal and oil.
Nonsymbiotic Mutualism: a relationship of relative independence, yet necessary for both species, as with bees and apple trees.
Nuclear Power: energy released by the fission (splitting) or fusion of atomic nucleii: in effect rending the very fabric of matter. The resulting heat drives electric generators. Although the average nuclear plant creates 20-30 tons of highly toxic byproducts and wastes a year, no one has thought up a safe way to deal with it (plutonium has a half-life of 24,400 years).
Nucleic Acid: a very long molecule made up of nucleotide chains carrying genetic information built from carbon, hydrogen, nitrogen, oxygen, and phosphorus. See DNA.
Nucleotide: a monomer (a chemical link in chains called polymers) composed of a sugar, a phosphate group, and a ringlike organic base.
Nucleus: in a cell, the organelle that contains genetic material (DNA and chromosomes); the cell's control center. Also: the center of an atom around which the electrons orbit.
Nuee Ardente: an ashy cloud of volcanic gas that churns downslope burning whatever it touches.
Null Model: a statistical model or computer simulation used to analyze something in a community or its environment.
Nutrient Cycling: the cycling of nutrients through the environment and its inhabitants from soil to plants to animals and back to soil.
Nutrient Traps: places where nutrients accumulate, as in estuaries.
Obligate: a species confined to a narrow range of conditions (e.g., plants that need a very specific soil pH).
Obliquity: the tilt of the Earth's axis (23.5° at present). The tilt makes seasons possible because at any given position in the Earth's orbit around the Sun, half of the planet will lean toward the sun as the other half leans away from it.
Obsidian: dark glass congealed from rapidly cooled lava. Often composed of rhyolite.
Occam's Razor: Franciscan priest William of Occam's admonition against unnecessary plurality in explanations of something not understood. In other words, simple explanations requiring fewer assumptions (crop circles are cut by pranksters on tractors) tend to work better than those requiring more assumptions (crop circles are cut by extraterrestrials who come here by an unknown means to make designs through an unknown method for unknown reasons before departing again without leaving any other evidence of their visit). Chalquist Trimming of Occam's Razor: although the most correct explanation is often the simplest, the most fruitful explanation is the one that opens up the most penetrating questions, respects the beingness of the phenomenon under study, stimulates imaginative discussion, and tends hypotheses that see through themselves with the highest degree of transparency.
Ocean Floor (Abyssal Plain): the surface of the oceanic crust 5,000 to 7,000 meters below the ocean surface. Ocean basins take up 30% of the Earth's surface.
Oceanic Crust: primarily basaltic and roughly 5 to 10 kilometers thick.
Oceanic Plate: a mobile chunk of primarily basaltic lithosphere floating on the asthenosphere below it. The plates are about 75 kilometers thick. Volcanism at the mid-ocean ridges produced them 700 million years ago. See Continental Plate.
Oil: hydrocarbon liquid commonly drilled from sedimentary layers packed with marine matter left over from the Carboniferous days. Its dark, spellbinding, "oildorado" properties include convincing large groups of people to vote against cheap public transportation and elevating pirates and robber barons into heads of nation-states. See Peak Oil.
Old Growth Forest: a relatively undisturbed forest containing many old trees and luxuriant levels of vegetation from the forest floor to its canopy. Logging old growth forests triggers ecological consequences, some known (loss of water, rainfall, habitat, oxygen, carbon, etc.) and some unknown.
Oligotrophic: low in nutrients, as in lakes high in oxygen but low in plant or animal life.
Omnivore: an organism that eats both plants and animals.
Ontogenetic Crippling: Paul Shepard's term for the emotional and spiritual stunting that results from growing up in a civilization at war with nature and afraid of close contact with anything wild. An example would be socializing hordes of people to be impulsive consumers, thereby strengthening their least mature tendencies while curtailing their capacity for critical thought.
The fact that millions of people share the same vices does not make these vices virtues, the fact that they share so many errors does not make the errors to be truths, and the fact that millions of people share the same forms of mental pathology does not make these people sane. -- Erich Fromm
Ontogeny: the development of an organism from the egg to maturity.
Opportunistic Success Strategy: species survival in unstable environments through rapid colonization and reproduction, low mobility, and high death rates. "It's better to burn out than to fade away." Contrast with Equilibrium Success Strategy.
Optimum Sustainable Population: pretentious term for "how many things can live in one place without using it up."
Organic: containing carbon; also, made of living things or the products of their decomposition, like humus.
Organic Farming: a form of small-scale agriculture that produces yields without introducing artificial fertilizers or pesticides. The basic aim is to grow things naturally with a minimum of mechanical interference. Organic farming grew in popularity from Sir Albert Howard's published observations of Indian farming techniques (1940).
Fairview Gardens, an organic farm and blossoming outpost of urban agriculture
flourishing in Goleta, California. Photo by C. Chalquist, 2005.
Organogenesis: the start of organ formation in the embryo.
Organophosphates: chemicals that kill pests by ruining their nervous system. Originally developed by the Nazis during the 1930s for use as bioweapons--"weapons of mass production," as President Bush would say. Currently the most popular class of pesticides. See Cholinesterase Inhibitors. (Chemicals from poisons and explosives, tractors from caterpillar-treaded tanks: over the years mechanized agriculture assumes more and more of the features of a war against the soil. See Agriculture.)
Orogenesis: tectonic mountain-building. They rise as continental plates smash together (case in point: the Pacific coast and its long range of mountains).
Orthographic Uplift: the rise of air masses bumping into a mountain range. Often results in rain on the windward side and a dry rain shadow on the lee side.
Orthographic Projection: a map simulating the Earth's three-dimensional surface on a two-dimensional chart.
Osmoregulation: the ability to control mineral and salt concentration in the blood. Some fish do this to help them move among waters that vary in salinity.
Outfall: wastewater discharge point.
Outgassing: release of gas from molten rock or from the Earth's interior. Ancient outgassing produced most of the Earth's atmosphere.
Out of Africa: the commonly accepted evolutionary hypothesis that all humans emigrated from Africa, a continent that hosted several hominid species.
Outwash Plain: flat layers of sedimentation left by melt from a retreating glacier. Some are arable.
Overburden: the soil and rock removed by mining.
Overland Flow: the downhill movement of a thin sheet of rainwater.
Overpopulation: some perspective: to reach one billion people took humanity from its beginnings all the way to 1830. The second billion arrived in a mere century, the third in 44 years, and the fourth in 12 years.
Overshoot: the crisis point of exhausting whatever resources were available. See Crash and Dieback.
Overstory: the canopy of a forest.
Ovary: in flowering plants, the enclosure around the seed-making ovules. The ovary becomes the fruit.
Overdrafting: taking more water from a well or aquifer than it can recharge. Results: a falling water table, subsidence (this is what made diking in Holland necessary), encroachment from nearby bodies of saltwater, and eventual exhaustion.
Ovule: the rounded plant outgrowth that produces the seed.
Oxbow Lake: a bend in a stream cut off from the rest of the water by erosion.
Oxidation: changing a substance chemically by adding oxygen to it. See Redox.
Oxidative Phosphorylation: the third stage in the breakdown of glucose into APT energy (see Carbohydrate Catabolism), in which electrons handed off by the mitochondrion's electron transport chain (see Krebs Cycle) are joined with oxygen to produce ATP inside the mitochondrion (the cell's power plant).
Ozone: a three-atom oxygen molecule that in its gaseous state screens ultraviolet radiation. The protective ozone layer hangs 10 to 50 kilometers above the Earth's surface.
Ozone Hole: a once-natural springtime thinning in stratospheric ozone over Antarctica, but now enlarged by CFCs and other pollutants into a hole the size of the Moon.
Paleomagnetic Dating: dating ancient minerals by using their magnetic properties to trace reversals in the Earth's magnetic field.
Paleoclimate: the reconstruction of ancient climatic conditions.
Palsa: a mound of earth, often peat, pushed up near the edge of a glacier.
PAN (peroxyacetyl nitrate): a pollutant found in photochemical smog. It irritates the eyes.
Pangaea: the 300-million-year-old supercontinent that plate tectonics split 200 million years ago into what have become the current arrangements of continents. There seem to have been at least two other supercontinents before Pangaea.
Panhumanism: Gary Snyder’s term for humanistic scholarship that fully embraces the nonhuman.
Parent Material: the minerals from which a soil originates.
Pasteurization: heating milk to kill microorganisms that could sicken humans.
Patch Dynamics: how similar components (patches) in an environment interact with each other. Used to study how patches of invasive species impact an ecosystem, among other things. Not to be confused with the actings out of Patch Adams, a famous and dynamic doctor arrested for protesting naked in San Francisco.
Paternoster Lakes: a line of mountain valley lakes carved by glacial erosion. From the air they resemble beads on a cord.
Pathogen: a microorganism that makes its host sick. Certain viruses, bacteria, and authoritarian flag-waving fanatics are common examples of pathogens. They tend to be parasites that weaken the organisms they feed upon until self-protective systems get rid of them.
Pattern Climax Theory: the pattern of climax vegetation tends to reflect the spatial variations of its physical environment.
PCBs: polychlorinated biphenyls. Fifty common chlorine compounds that grow stronger as they move up the food chain. Odorless and tasteless, they came from electronics manufacturing until laws were passed to forbid their production and release. They are still plentiful in the air, soil, and water, however. Symptoms vary from depression, rashes, and acne to gastrointestinal and liver damage.
Peak Oil: the growing conviction that oil production has peaked in most oil-rich parts of the world and is now declining. Once laughed at by conservatives and pro-industrial energy advocates, the idea now gains ground as oil production continues to drop and gasoline prices soar.
Peat: partially decomposed remains of plants that once flourished in a waterlogged environment.
Pedanticism: consumed by intellectual detail at the cost of coherence or relevance. The driving force is usually a bitter blend of perfectionistic fussiness and nerdy narcissism. The sight of psychologists, ecologists, and academics engaged in heated struggles about the definition of an ecological concept while the ecosphere burns is a lamentable one.
Pediment: a gradually sloping bedrock surface at the alluvial foot of eroded mountains. Often seen in dry regions.
Pedalfer: soils of humid regions; usually rich in alumina and iron but poor in carbonates.
Pedocal: soils of arid regions; tend to be rich in carbonates (especially lime).
Pedogenesis: uptight word for soil formation.
Pelagic: on the open ocean, like jellyfish.
Perennial: plant species that bears and seeds more than once. Perennials tend to take longer to produce a food yield than the quick-growing annuals so heavily exploited by traditional agriculture, but they last longer and do better in marginal soils. See Annual.
Periglacial: near a glacier. Usually refers to landforms shaped by glaciation.
Perihelion: the point in the Earth's orbit when it is closest to the sun (147.5 million km). Perihelion occurs on the 3rd or 4th of January. The opposite of Aphelion.
Peripheral Isolate: a group that ends up far from the parent species. See Speciation.
Periphyton: tiny organisms like algae and diatoms that cling to the underwater roots of aquatic plants.
Periodic Table: a list of all known elements (substances whose atoms are all of the same type). Some of the heavier elements only exist in laboratories.
Permaculture: coined in 1978 by Australian ecologist Bill Mollison and his student David Holmgren as a contraction of "permanent agriculture" or "permanent culture." Permaculture involves designing ecological human habitats and food production systems emphasizing relationships between elements in (zones) and energies (sectors) that integrate human dwellings, microclimate, annual and perennial plants, animals, soils, and water into stable, productive communities. According to Holmgren, permaculture is the use of systems principles and design thinking to make landscapes that mimic the patterns and relationships found in nature while yielding abundant food, fibre, and energy for human needs. Emphasis is on multi-use plants, cultural practices like sheet mulching and trellising, and encouraging animals to recycle nutrients and graze weeds. Community planning includes energy-efficient buildings, waste water treatment, and growing healthy soils as well as plants. "Without permanent agriculture," writes Mollison, "there can be no possibility of a stable social order."
Other permaculture practices:
- Zones are laid out from the center (the dwelling) in terms of how many visits daily we need to make to something. Sectors: energies coming toward the house to be shielded, deflected or collected (ponds, banks, hedges, walls, screens, trellises, hedges, etc).
- Elements are placed in zones to work together, as in the natural world, and placed to serve two or more functions (a tree for shade and for erosion control) while managing sector energies (blocking rough winds). Hedges provide forage, shelter crops, provide mulch, exclude rampant grss or weeds, exclude browsing animals. Swales manage drainage and help trees survive drought.
- Likewise, every function (water collection, fire protection, etc.) is served in two or more ways.
- Plants that attract beneficial insects: buckwheat, clovers, corlander, coreopsis, corn cockle, cosmos, dill, fennel, feverfew, mustard, sweet alyssum, tansy, tidytips, yarrow. Alfalfa, sweet clover, comfrey, dandelion, earthworms, mulch, and daikon radish break up hardpan.
- Water--drainage, collection, availability--is the chief design consideration. Storage sources should be placed on a slope above the site for gravity feeding downward. Roofs can collect rainwater in covered drums. Wire fences to drip dew on the plants below.
- Everything is a resource. Pests tell something about soil and plant problems. Predators manage them.
- Three key permacultural ethical principles: care for the earth, care for people, set limits to consumption and reproduction, and redistribute surplus.
- Principle of Stability: it is not the number of diverse things in a design that leads to stability, it is the number of beneficial connections between these components (Mollison).
- Edge cropping: use of edges and zones, which tend to be areas of diversity and production.
- Windbreaks (ideally one-fifth as high as the space between them) to preserve moisture; plant mulch-producing crops near them. Interplant leguminous trees in a crop and orchard for mulch, soil-building, frost cover, leaf drip. Wire fences above crops to feed them dew. Whitish plants like wormwood and birch to deflect sunlight and lower temps, or dark ones to retain it. Lots of trees for condensers, water-catchers, etc.
- Mollison's Prime Directive of Permaculture: “The only ethical decision is to take responsibility for our own existence and that of our children. Make it now.”
Permafrost: permanently frozen subsoil. Five types: continuous permafrost, discontinuous permafrost, sporadic permafrost, alpine permafrost, and subsea permafrost.
Permeability: how easily soils and rocks transport water horizontally and vertically. Shale is porous and therefore permeable, as is sand and gravel; granite and clay are not.
Persistence: how long a population lasts.
Pests: anything that eats or damages what we eat. Too many pests mean not enough predators, like fish or birds for mosquitos and gopher snakes for gophers, who also avoid daffodils, elderberry cuttings, and castor beans. Teas made of chamomile, stinging nettle, comfrey, or horsetail discourage harmful fungi. Marigolds control whiteflies, spearmint, tansy, and pennyroyal control ants, Mexican marigold controls nematodes and root pests, as do French marigolds; yellow nasturtiums decoy black aphids, which are repelled by spearmint, stinging nettle, southernwood, and garlic, and borage repels tomato worms while attracting helpful bees.
Petrochemicals: chemicals made from natural gas or petroleum (crude oil).
pH (Potential Hydrogen): a scale to measure the alkalinity or acidity. Substances with a pH below 7.0 are acidic (high in free hydrogen ions), and those above 7.0 are alkaline, with 7.0 neutral. Acids tend to be sour and corrosives, and bases (alkaline compounds) the opposite, and slippery. Rainy climates tend to produce acidic soil, dry climates alkaline soil. For growing food, soil pH should fall between 6.3 and 6.8. Lime is sometimes added to acidic soil and sulfur to alkaline soil. The more humus in the soil to buffer it, the less pH impacts fertility.
Phase Change: the transformation of one physical state into another--gas into liquid, solid into gas, etc. Always requires an exchange of energy, whether an increase or decrease.
Phenotype: the outward, bodily manifestation of the genotype (genetic constitution). Phenotypes are the aspect visible to natural selection: echo location makes some dolphins more viable, so the genes those dolphins carry are passed on. The phenotype extends to the organism's environment: coral for eels, nests for birds.
Phloem: the tissue in plants that conducts food by means of hydrostatic pressure.
Phosphorylation: the "recharging" of ATP, the universal energy of biological activity.
Phosphorus Cycle: cyclic movement of phosphorus from environment to organism and back, starting with phosphate rock dissolved by water into plant roots.
Photic Zone: the watery layer through which light penetrates to nourish photosynthetic marine organisms like plankton.
Photochemical Smog: air pollution produced by the reaction of hydrocarbons, nitrogen oxides, and sunlight. Automobile and industrial exhausts are major contributors.
Photoperiodism: an organism's responsiveness to changes of daylight or season.
Photon: a packet of light energy. Beams of light are composed of photons.
Photosphere: the light-giving surface of the sun.
Photosynthesis: the conversion of sunlight and carbon dioxide into oxygen and glucose (used for energy, starch, cellulose, etc.). Plants do it with a light-sensitive organelle called the chloroplast. Photosynthesis gave us not only food, but the atmosphere we breathe.
Phototropism: the tendency of plants to turn toward and follow the sun.
Phylogeny: patterns of evolutionary lineage (like tree shrews to people). See Ontogeny.
Phytoplankton: green microscopic plants, typically algae but including diatoms, desmids, and dinoflagellates. Upon their photosynthetic selves hang the food webs of the oceans.
Piedmont Glacier: a large lobe of ice spilled out of a glaciated valley.
Pingo: a conical mound of soil-covered ice pushed up from ground permeated by permafrost.
Pioneer: a plant species that establishes itself in a bare area like a recently leveled field until successional species move in. Many annuals are pioneer species. Many tend to be invasive.
Pistil: the female reproductive organ of a flower. Carpels (ovule-bearing leaves) compose it, and stamens, petals and sepals ring it. A flower without stamens is a pistillate.
Place, Versus Space: various ecological thinkers have pointed out that in the West, the felt sense of place--that tree, this brook, my room--has slowly given way to the abstract notion of space: a chunk of real estate, a Cartesian grid, a sector on a map. Philosopher Ed Casey points out that many languages contain this place/space distiction, which in the West goes back at least as far as Plato's Timaeus. Our cultural preferrence for space to place survived even the Einsteinian destruction of categories like absolute time and space: in fact, "place was absorbed into space." This has far-reaching consequences for how we experience ourselves as subjects, lost and place-impoverished, in a conceptually dematerialized world. (Casey points out, for example, the word morality goes back to a term for "custom," whereas the word ethics refers ultimately to the place where the horses went home at night. For more information, see his Getting Back into Place and The Fate of Place.)
Placeworld: Ed Casey's term for the felt, lived reconnection of space and place. An example is how the self experiences itself as firmly located somewhere specific rather than feeling lost in a sea of plots or coordinates.
Placer: a surface deposit of heavy mineral particles like gold or platinum. In the mid-1800s, placer mining by pick and pan gave way to powerful hydraulic hoses that washed away entire hillsides.
Plankton: microscopic algae and protozoa drifting in water. Larger organisms graze them like grass.
Plate Tectonics: the movements of continental plates over the mantle whose currents pull them around the Earth's surface. As far back as 1912, Alfred Wegener noted that the continents fit together like puzzle pieces into some lost whole (see Pangaea, a name he coined). He was ignored, but in 1929, Arthur Holmes decided that thermal convection currents in the mantle could move continents around. These ideas also account for where the seafloor comes from (molten material emitted through cracks between plates), how some of it disappears (when the edge of one plate vanishes under another--subduction), and why volcanic and mountain-building activity so often surfaces in belts (plate edges).
Platypus: often poked fun at as an egg-laying mammal, the platypus sports a remarkable bill that detects its prey buried by generating an electric field.
Platyspermic: possessing flattened, disc-shaped seeds. Contrast Radiospermic.
Playa: a temporary, shallow body of water with a clay bottom. Also, a dry desert lake bed.
Pleiotropism: how a single gene can express itself in several seemingly unrelated manifestations. Mutations often do this. (To use the example of Richard Dawkins, genes function not as blueprints, but as recipes.)
Plicate: a fanlike folding (e.g., the leaves of palms and various orchids).
Plowing: a method of turning soil to enhance productivity and destroy soil structure. Late in the 7th century, northern peasants began using a new type of plow, equipped with a vertical knife to cut a furrow, a horizontal blade to slice under the surface, and a moldboard to turn it over: a cross brought down into the earth. (Rotating crosses called windmills pumped water from the sinking Netherlands, an effort first funded by the church.)
Plucking (Quarrying): glacial erosion in which frozen wedges of ice are pulled out of rocky cracks by a passing glacier.
Pluton: a large mass of intrusive igneous rock. Named after Pluto, god of the underworld, whose name also means "wealth."
Podzolic: moderately to highly acidic soil. See pD.
Podzolization: formation of acidic soils through leaching and other natural processes.
Point Bar: a sedimentary deposit (normally sand) inside the bend of a channel. Tends to build outwards.
Point Source: a specific, identifiable source of pollutants, like the BP oil refinery in Carson, California.
Pollard: a tree cut back to the trunk to make its branching or foliage denser. Also, an animal without horns (e.g., a sheep).
Pollen: dustlike microspores that carry a seed plant's male sex cell.
Polyclimax Theory: environments contain numerous points of relative stability that enable more than one species to flourish as a climax community. Contrast with Monoclimax Theory.
Polycyclic Aromatic Hydrocarbons (PAHs): over a hundred organic carcinogens produced by the incomplete burning of oil, coal, gas, tobacco, garbage, and even meat. Some are used in pesticides. Aside from causing cancer, their impact on humans is unknown, although test animals exposed to them lost the ability to reproduce.
Polycyclic Landform: one exposed to more than one cycle of geomorphic change over time, as with a mountainside sculpted by weathering, then by erosion, and later by weathering.
Polyculture: the planting and growing of more than one species together, as natural world does it. Different from Monoculture.
Polygenetic Landform: one shaped by more than one type of geomorphic transformation, like a slope that is partially chemically weathered and partially built up by deposition.
Polymer: a large molecule assembled chemically by repeating molecular building blocks (monomers) through a reaction called polymerization. Not all polymers are organic, although most are.
Polymorphism: the expression of two or more of a gene's alleles (varieties) in a population. Human hair and skin color are polymorphous.
Polyp: a coelenterate (corals, sea anemones, jellyfishes, and hydroids) with a hollow cylindrical body anchored at one end and open at the other, where a mouth is fed by tentacles.
Polyphagous: predators that consume more than one species of prey.
Pore Water: water in the spaces between the grains of sediment. Often used for toxicity testing of a nearby body of water.
Porosity: the amount of space within rocks or soils.
Potash: potassium carbonate. Sometimes obtained from wood ashes.
Potentially Renewable Resource: one that is either inexhaustible, like solar or wind energy, or replaceable, like wood from trees.
Prairie: an extensive, uncultivated tract of level or rolling grassland with no or few trees. Its soils are usually fertile.
Prairie Pothole: wetland marshes or depressions left by glaciers. Prairie postholes scattered across the Upper Midwest of North America host 50% of the continent's migrating waterfowl.
Precession of the Equinoxes: the circular wobble in the Earth's axis. The planet spins unevenly like a top on a table, pulled on by the sun and moon. It takes approximately 26,000 years to accomplish one complete wobble. Because of it, the spring equinox--the point where the Sun crosses the celestial equator late every March--appears from the earthly point of view to be sliding out of the constellation of Pisces and into Aquarius.
Predator-Mediated Coexistence: predation that thins out a prey species enough to keep it from competing another species out of existence. Very common in rocky intertidals.
Predator Switching: a predator's ability to hunt a different species for prey when its preferred species has declined or disappeared.
Primary Consumer: an organism that eats green plants.
Primary Producer: an organism that makes its own food through photosynthesis (plants) or chemosynthesis (certain microorganisms). Primary producers form the foundation of the food web.
Primary Air Pollutant: a pollutant dumped directly into the air. (Photochemical smog is a secondary air pollutant: it is chemically derived from primary pollution.)
Privatization: when a political administration transfers resource oversight from public regulation into the ownership of those who support that administration so they can privately do what they wish with the resource.
Processed Foods: those made in factories and altered with additives, preservatives, colorings, and flavorings. Making them drains most of the nutrients out; processing them adds nutrients back in. Companies that sell processed food have begun marketing low-fat versions because of obesity concerns. A steady diet of processed meats (hotdogs, hamburgers, etc.) is suspected of a link with pancreatic cancer.
Procumbent: having stems that trail along the ground without rooting. Creeping vines.
Productivity: the rate at which a group of organisms produces biomass.
Progenesis: sexual maturity reached while still in the larva stage. See Neoteny.
Progradation: the natural extension of a shoreline seaward.
Progress: an ideological justification for nonsustainable exploitation of natural resources. Stating that "Progress is inevitable" without mentioning who profits from such an aggressive ideology is like stating that "Rudolf the Red-Nosed Reindeer is a part of Christmas" without mentioning that Rudolf was invented in 1939 by Montgomery Ward as part of a holiday advertising blitz. (Rudolf's original name was Rollo, but they canned it because it announced the conquest theme too openly.)
Prokaryote: an organisms whose cells lack a nucleus. Roughly synonymous with bacteria, but divided into eubacteria and archaeans. See Eukaryote.
Propagation: breeding plants. Methods include division (separating one plant into several), ground layering (bending a shoot from the parent plant into the soil so it will root there), budding (inserting a parent plant bud into a second plant's rootstock), and grafting (joining a stem from a parent plant onto a second plant's rootstock).
Propagule: a seed, spore, or cutting that grows into a plant.
Protein: extremely complex molecules of carbon, hydrogen, nitrogen, and other elements joined in chains of amino acids (peptides). Protein constitutes the bulk of living matter, gives it structure, and has something to do in almost every aspect of cell operation.
Protist: simple, usually one-celled animal whose cells contain a nucleus. Examples include flagellates, amoebas, ciliates, sporozoa, radiolaria, and slime molds. Some (microalgae) are photosynthetic; most are microscopic; all sit at the base of the food web.
Proton: a positively charged particle in the nucleus of an atom. The number of protons determines the nature of an element: one proton for hydrogen, two for helium, etc.
Protoplasm: a generic for living matter.
Protozoa: tiny, single-celled animals without a backbone. Usually classed with the protists.
Pruning: cutting away stems or branches to improve a plant's vigor. Candidates include branches with a lot of bulk but little foliage, weak branches, V-shaped crotch branches, water sprouts, crisscrossed branches, double leaders, shaded branches, and crown sprouts.
Pseudofeces: undigested food particles bound in mucus and discarded by oysters and mussels. Some bottom-feeding organisms eat it.
P-Wave (Pressure Wave): a seismic oscillation that moves forward and backward rather than side to side. An earthquake's first large jolt. See S-Wave.
Pyramid of Biomass: a diagram showing the biomass supported at each trophic level of a food web. Primary producers are at the bottom and predators are at the top.
Pyramid of Energy Flow (Trophic Pyramid): a diagram showing the flow of energy through the trophic levels of a food chain or web. About 10% of the usable energy at one trophic level makes it to the next. Many small organisms are needed to feed relatively few larger ones.
Quadrat: a small area set aside for ecological study.
Quark: the particle that makes up protons and neutrons. Although the quark is our current most fundamental particle, some physicists suspect that in a universe of shifting relational energies, the very notion of a smallest chunk of building block is wrong-headed.
Quartz: a hexagonally latticed silicon dioxide mineral. A chief component of sand and therefore sandstone. It is the second most abundant mineral after feldspar and is common in continental crust but rarer in oceanic crust.
Quartzite: metamorphic rock rich in quartz recrystallized from sandstone.
Radicle: the root of a plant embryo; the first part of a seedling to emerge during germination.
Radioactive Decay: the decay of an unstable nucleus (radionuclide) of an atom losing protons, neutrons, or photons at random.
Radiospermic: possessing round seeds.
Rainforest: an evergreen forest growing in a wt, humid climate. Rainforest coverage prevents desertification and drought and hosts more than half the world's animal species. Every day unchecked industrial development flattens a patch of rainforest the size of New York City.
Rain Shadow: a rainless region on the lee side of a mountain. Clouds have often been drained of rainwater by the time they reach it over the mountain.
Reaeration: mechanical augmentation of dissolved oxygen in water, as in cresting waves or below waterfalls.
Realized Niche: the part of a niche actually occupied by a species. Contrast with Fundamental Niche.
Reclamation: "reclaiming" apparently useless lands for human development, as when an ecologically rich wetland is drained and converted into cropland. Also: reusing or recycling water.
Red Bed: red sedimentary layers of sandstone, silt, and shale colored by iron oxides; often seen in the American Southwest.
Redox (Reduction-Oxidation): a chemical transformation in which electrons are removed from one substance (oxidation) and added to another (reduction). The reductant transfers electrons to the oxidant. Redox reactions transfer biological energy. In photosynthesis, carbon dioxide is reduced into sugars; in respiration, sugars are oxidized to make carbon dioxide and water.
Red Queen Hypothesis: sexual reproduction makes evolutionary sense despite its complexities because it allows species to evolve new defenses against parasites. (Some lab evidence suggests that sexual reproducers fend off parasites more efficiently than asexual reproducers.) Also: biologist Leigh Van Valen's idea that a species must develop continuously just to keep up with species co-evolving with it. (Red Queen refers to a chess piece in Lewis Carroll's book Through the Looking Glass who tells Alice that one must run just to stay in place.)
Red Tide: a phytoplankton algae (dinoflagellate) bloom that spreads naturally just offshore but can be triggered by nutrients dumped into the water. Red tides can cause fish kills and infect shellfish with biotoxins.
Re-Entrant: a geographical pointing inward, as with bays and inlets; the opposite of Salient.
Refugium: a refuge from predation. The mouse that makes it into the hole escapes the cat.
Regolith: a layer of loose, weathered or eroded material covering rock. An important habitat for both plants and animals who cannot make a home in solid rock.
Reinhabitation: the bioregional goal of living consciously and sensitively in one's locale. This includes giving key decision-making power, economic and political, to locals who know what the place where they live needs. See Bioregionalism.
Residence Time: the amount of water held in a given body divided by the amount that flows into and out of it. (The oceans' residence time is roughly 40,000 years. By contrast, the average turnover time of a stream is about two weeks.)
Resilience: the ability of a biotic community to return to its former state after a disturbance.
Resource Partitioning: the evolved knack of either sharing resources or using them in ways that avoid competition (e.g., one animal eats the top of a plant and another eats the roots).
Respiration: the conveyance of oxygen to cells and tissues as carbon dioxide and water are given off. In cells, the conversion of food (e.g., glucose) into energy. In most organisms, respiration releases the energy that drives metabolism.
Resuspension: dispersion of particles back into water, as when wave action or dredging stir up sediments that had fallen out of suspension and settled.
Retrogressive Succession: when a plant community gradually undergoes simplification, a thinning of variety, and a reduction in mass. Often associated with a deterioration in the environment.
Return: wastewater returned to a water source. Even when cleaned, returned water of a temperature different than where it heads can be damaging, as when heated water from a power plant kills fish in an estuary.
Rhapsodic Intellect: Theodore Roszak’s term for the integration of intellect, body, and emotion that makes an ecological sensitivity possible.
Rhizoid: a rootlike outgrowth that attaches a plant (hornworts, liverworts, mosses) to the ground.
Rhizome: a horizontal underground stem from which spring shoots, buds, and roots. A potato is a thickened rhizome. Found in ferns, horsetails, and asparagus.
Ria Coast: an elaborately sculpted coast with prominent capes or headlands and deep bays or inlets. Formed by either the submergence of a continental landmass or a sea level rise.
Richness: the number of diverse species occupying a particular area. A sample with 50 species is richer than a sample with 5.
Richter Scale: an obsolete logarithmic scale of 1-10 that measures earthquake magnitude (but not its felt intensity). Created in California by Charles Richter. See Moment Magnitude Scale.
Riffle: a stretch of rapid, shallow water flow, as in a stream, broken up by bar deposits, rock, or gravel. In streams pools often alternate with riffles. Also: mining term for the slats on a sluice that catch heavy minerals.
Rift: a zone between two diverging tectonic plates. Often volcanic, and a site of new sea floor.
Rift Valley: a long, narrow valley subsided between parallel faults. It is possible that the African Rift Valley separated an apelike ancestor into two groups, thereby allowing us to evolve separately from today's chimpanzees.
Riparian: adjacent to a river or stream. Riparian zones exchange organic matter between wet and dry habitats and regulate erosion, sedimentation, temperature, and nutrients.
Riparian Laws: the antiquated European feudal idea that who owns the banks owns the water. Turkey has relied on this argument to take water from the Tigris and Euphrates Rivers even though Syria and Iraq also depend on it. (The argument is specious: were air a resource that confines itself to channels, no one would claim the right to withhold it from people living downhill from its source.) See Hydraulic Despotism.
Riprap: rock, concrete, brick, etc. assembled into shoreline facing to check erosion.
Riplines: channels cut in gullies to reduce erosion.
Riverain: vegetation near watercourses. Sometimes used as a synonym for riparian.
RNA (Ribonucleic Acid): a versatile nucleic acid that combines with a protein to make ribosoomes, the site of protein assembly (ribosomal RNA); copies genetic information from DNA for transformation into proteins (messenger RNA), and incorporates animo acid combinations into developing proteins (transfer RNA). The RNA molecule is identical to DNA (from which it is made) except for the sugar ribose instead of deoxyribose and uracil for thymine. At one time RNA might have been the only form of life (the RNA World hypothesis): it can replicate without a cell nucleus or even any DNA.
Roche Moutonnee: a resistant, sheep-shaped mound of bedrock left by glacial erosion. Its slope is gentle where the ice advanced and jagged and plucked on the other side.
Rock Cycle: the cycle of transformations between igneous, metamorphic, and sedimentary rock over time. (Rocks are composed of crystals: liquids whose atoms form lattices when congealed.)
Rock Flour: rock ground to a powder beneath a glacier.
Roll Cloud: a rotating, cigar-shaped cloud that sometimes precedes a thunderstorm. Often seen in UFO photographs.
Rotation: using the same soil to grow different crops. Interrupts cycles of weeds, diseases, and insects; builds organic matter, improves soil structure. Useful rotations: nutrient-grabbing crops like corn, celery, and potatoes with those that need less, like garlic, mustard, or shallots; and shallow-rooting crops with deep ones. (Soil improvers: broad beans, lima beans, peanuts, peas, shell beans, snap beans, soybeans.)
Rotation Cycle: the time interval between the cutting and recutting of a stand of trees. In the U.S., the average rotation cycle has bowed to economic pressure by falling from 120 years to 40.
R-Selection: rapid growth and occupation through early reproduction, short life spans, low biomass, and lots of offspring. See K-Selection.
Rubisco: the protein that fixes carbon during photosynthesis. The most common protein on earth.
Runoff: a lateral flow (unlike leaching, which is vertical) that carries soil, minerals, waste, or pollution.
Ruminant: a hooved mammal that eats its food, regurgitates it (cud), and eats it again, a procedure made possible by a four-chambered stomach. Ruminants include cattle, bison, sheep, deer, goats, elk, giraffes, antelopes, and camels. Their specialized stomach evolved to extract the maximum of nutrients from low-quality food.
Rust: a fungal pest that raises brown lesions on plants. It never sleeps.
Salient: a geographical pointing outward, as with promontories and capes.
Salinity: the concentration of salts dissolved in water, measured in parts per thousand. Seawater averages 34 ppt.
Salinization: accumulation of salt on topsoil. Caused by irrigation. Around the world, 50-75 million acres of once-arable land are too salty to grow food in. Heavily salinized land is not arable until the salt is leached out of it. Several civilizations have fallen because of the resulting ecological damage.
Salmonella: a diarrhea-producing intestinal bacterium that causes typhus and poisons raw milk, eggs, meat, and poultry.
Salt: sodium chloride. Also, compounds produced when an acid's hydrogen atom is replaced by a metal atom. Also, what unscrupulous fast food restaurants do with french fries and potato chips in order to sell more drinks to thirsty customers.
Saltation: the movement of a particle transported by wind or water, one too heavy to remain in suspension.
Sandstone: a soft sedimentary rock composed of feldspar and weathered quartz grains. Porous sandstone layers often hold water in aquifers.
Saprophyte: an organism that eats dead organisms, thereby recycling the nutrients. Fungi and bacteria are examples.
Savanna: flat tropical or subtropical grassland with occasional shrubs, herbs, and trees.
Scald: exposed hardpan.
Scarification: extensive, artificial earth movement that exposes the underlying soils. Also, to nick and weaken a seed coat enough for germination.
Schist: a medium to coarse metamorphic rock of elongated minerals. It splits along parallel bedding planes. Often found in the company of tourmaline and garnet.
Scion: the stem that's grafted onto a waiting rootstock.
Sclerophyllous: small, tough, drought-resistant evergreen leaves. Also, a plant whose deep roots and small leaves resist water loss.
Scrapie: a fatal degenerative disease that destroys the nervous systems of sheep and goats. Named after the infected sheep's habit of scraping its itchy skin against trees and bushes.
Scree: a pile of weathered rock fragments at the bottom of a slope or cliff.
Scrub: small or low bushes or trees. Common in dry and alpine regions.
Sea Breeze: the daytime movement of air from water to land down a pressure gradient. See Land Breeze.
Seafloor Spreading: the creation of seafloor crust moving outward from the mid-oceanic ridge.
Seamount: a submarine mountain raised by volcanism.
Sea Stack: a column or pillar of rock near a coastline. Shaped from eroded headlands.
Second Law of Thermodynamics: energy (usually heat) dissipates in any closed system (entropy). This is why trophic levels in a food web narrow as they rise.
Secondary Consumer: a predator that eats plant-eating prey (primary consumers).
Section: 640 acres (1 square mile).
Sedge: Grass-like plant that is adapted to grow in moist habitats. John Keats saw some withered from the lake.
Sedimentary Rock: rock compressed and cemented (lithification) from the weathered deposits of older rocks (clastic), from chemical precipitates, or from organic deposits. Limestone, chert, halite, chalk, shale, sandstone.
Sediment Sink: a place where beach sediment leaves a coastal area.
Seed-Saving: collecting seeds (those passed down in families are called heirlooms), a practice that preserves the precious genetic diversity now threatened by agricultural seed monopolies.
Seed Pelleting: coating a small seed with a substance that makes planting it easier. Using organic and mineral material to create the pellet stresses the environment less.
Seiche: a sudden oscillation in pond or lake water due to wind, weather, earthquakes, etc.
Seif: an elongated sand dune formed parallel to the prevailing winds. Also, a dune formed by winds from multiple directions.
Selective Cutting: cutting only mature or diseased trees. Compare Clear-Cutting.
Self-Pruning: when lower tree branches fall off and die because they haven't received enough light
Self-Reliance: broad term for the various movements and practices toward becoming less dependent on external sources of food and power. Some have suggested that "interdependency" would be a better term for the renewed emphasis on local, sustainable projects, and democratic experiments in self-governance.
We know how to solve every food, clean energy, and sensible shelter problem in every climate; we have already invented and tested every necessary technique and technical device, and have access to all the biological material that we could ever use....The tragic reality is that very few sustainable systems are designed or applied by those who hold power, and the reason for this is obvious and simple: to let people arrange their own food, energy, and shelter is to lose economic and political control over them. We should cease to look to power structures, hierarchical systems, or governments to help us, and devise ways to help ourselves. -- Bill Mollison
Semi-Diurnal: twice daily.
Sentinel Species: see Indicator Species.
Sepal: the bud-protecting leaf structures of a flower.
Seral Stage: one of the intermediate stages of ecological succession between pioneering and climax. See Succession.
Sessile: attached; non-mobile.
Sexual Reproduction: creating offspring by fusing gametes (sex cells). Contrast with Asexual Reproduction.
Shale: a fine, layered, cleavable sedimentary rock composed of clay or similar small particles. Shale deposits sometimes contain or are found near coal or oil.
Sexual Selection: a form of natural selection in which characteristics (e.g., bright plumage, deeper voices) preferred by female mates are passed down to later generations.
Shear Wave: see S-Wave.
Sheet Erosion: the removal of a layer of soil by rain or runoff. Topsoil accumulated for centuries or eons can erode away in minutes unless anchored with vegetation and properly drained.
Shoaling: decrease in water depth, especially near a shoreline.
Shelterbelt: a barrier of trees or other vegetation planted to block incoming winds. Shelterbelts prevent moisture loss and erosion.
Shield: a large formation of ancient (Precambrian) igneous and metamorphic rock that constitutes the core material of the continents.
Shield Volcano: a wide, shallowly sloping volcano built from recurring flows of basaltic lava.
Shrub: generic name for a woody perennial plant without a well-defined main stem. Bushes and hedges.
Side-Dress: to place fertilizer or manure around or beside plants.
Silage: a green crop stored in a silo to moisten it. Usually corn, but also grass, sorghum, legumes, and sunflowers, among others.
Silica: a transparent mineral of silicon dioxide. Found in glass, quartz, opals.
Siltation: the accumulation of small-grained sediments brought by water. A major problem of many dams and deep water ports.
Sink: a depression or hole opened by sand or soil erosion caused by poor drainage. Common after a lot of rain, especially in heavily paved areas. Also: a place where unrecycled compounds accumulate.
Sinusoidal Equal-Area Projection: a roughly diamond-shaped map projection whose distances are accurate only along the parallels and the central meridian. Distortion increases near the poles and away from the center bulge.
Slate: metamorphic rock hardened from shale.
Slip Erosion: a landslide.
Slip-Face: the lee side of a dune.
Slough: a swampy inlet.
Snag: a tree that's dead but still standing.
Snibbiting: taking the top of a plant and replanting the rest of it.
Snout (Terminus): the front of a glacier.
Social Ecology: a discipline that links ecological problems with social problems: “…The hierarchical mentality and class relationships that so thoroughly permeate society give rise to the very idea of dominating the natural world” (Murray Bookchin). Some key emphases:
- The paradigm of domination of nature followed from domination of society by the state and, before that, of women by men.
- Institutionalized hierarchy and domination damage the biosphere and subjugate humans to widespread social injustices. They should be replaced by practices that favor thinking and acting in terms of complementarity.
- The artificial bifurcation of the world into "natural" and "unnatural" (human) cannot stand. We are part of the natural world we damage through our "second nature" symbol-juggling capacities.
- Capitalism based on perpetual expansion is wasteful and outmoded.
- The crisis of our time is not the emergence of cities, but of an urbanization that ruins cities and rural areas alike.
- Bookchin criticizes deep ecology’s blindness to the emergence of hierarchy: “As long as hierarchy persists, as long as domination organizes humanity around a system of elites, the project of dominating nature will remain a predominant ideology and inevitably lead our planet to the brink, if not into the abyss, of ecological extinction.”
Society: a local climax community.
Soil: a mixture of humus and particles weathered from rock. A cubic yard of soil will cover 300 square feet of ground to a depth of 1 inch. The major nutrients are nitrogen, phosphorus, and potassium. Bacteria and fungi produce humus. Half the volume of good soil is pore spaces. Microbial decomposers account for 60-80% of total soil metabolism; bacteria drive nitrification, sulfur oxication, and nitrogen fixation. Actinomycete microbes help form humus; they are the most numerous organisms after bacteria. Soil texture means the relative proportions of sand, silt, and clay. We live on 1/12 of the Earth’s surface but have discarded ¾ of its productive soil. Replacement of an inch of topsoil takes 500 years.
Soil Colloids: tiny organic and inorganic (often clay) particles found in a soil. They carry a negative electrical charge, have much to do with the soil's chemistry, and serve as the primary sites for cation exchange and the capture and transport of nutrients.
Soil Creep: the slow, gravity-driven mass movement of soil downslope.
Soil Horizons: its layers, which from top to bottom are the O-horizon (or zone of leaching) of freshly fallen plant litter, leaves, an A sublayer of water-holding humus, and another of insoluble minerals, a B-horizon (or zone of deposition) of clay and other inorganic particles, and a C-horizon with rock fragments weathered from the bedrock.
Soil Profile: the overall vertical arrangement of layers or horizons in a soil.
Soft Technology (Appropriate Technology): the non-intrusive kind that does not harm the Earth: small, decentralized, inexpensive.
Softwood: wood from gymnosperm trees (redwood, pine, fir, spruce--conifers). See Hardwood.
Solarization: covering planting beds with plastic sheets during the summer in order to control weeds.
Solstice: two annual dates when the sun is farthest from the celestial equator: June 21 or 22, when it stands the farthest north, and December 21 or 22, its southernmost position (in the northern hemisphere; dates for the southern hemisphere are the reverse).
Solum: the A and B horizons, where things grow.
Sorghum: a tall annual cereal used mainly for feed grain and syrup.
Specialist: an organism that uses a narrow range of resources with high efficiency. The panda is a specialist who harvests the bamboo that makes up most of its diet.
Speciation: the evolution of a new species. This usually happens through either geographical separation over long periods of time, or through reinforcement, in which subtle differences in characteristics like calls or wing markings are more favored in mates. When Agrodiaetus butterflies live together, for example, the males tend to develop markings that distinguish them by species. Females of the same species prefer them. This provides the kind of breeding barrier an ocean or mountain range might.
Species: a group of organisms that can breed with each other.
Species-Area Curve: species richness tends to increase in roomier areas.
Speciesism: term coined in 1970 by British psychologist Richard Ryder to denote a form of prejudice against nonhuman species. An example would be the belief that animals have fewer rights than humans because of lesser intelligence.
Spermatophyte: a seed plant. Many spill their seeds upon the ground.
Spicule: pointed skeletal elements found in certain sponges and sea cucumbers and made from either silica or calcium carbonate. They provide structure and protection.
Spiegelman's Monster: a strand of self-replicating RNA created by microbiologist Sol Spiegelman by putting a simple viral form in an environment that would nourish it. What started out as an RNA strand with 4,500 nucleotide bases ended up as a minor genome trimmed down to 220 bases and able to out-replicate any competition. Life as we know it might have begun somewhat similarly.
Spore: a seedless embryo.
Spring Tide: the high and low tide preceding a neap tide. Combined tidal pulls from Sun and Moon make the tide rise higher and fall lower than normal.
Square-Foot Gardening: a system of gardening developed by Mel Bartholomew that uses four-foot-square plots subdivided into one-foot squares for growing vegetables that use little space but are easy to tend.
Stacking: planting to take advantage of vertical growing space.
Stamen: a pollen-generating stalk at the base of a flower's petals. Flowers typically have six of them, just to make certain.
Standing Crop: the biomass of a trophic level, community, population, or species at a certain time and place.
Starch: a complex carbohydrate used by plants to store glucose as food energy. Starches make up corn, wheat, rice, potatoes, beans, and other vegetables.
Stenobathic: able to tolerate only small changes in water depth (see Eurybathic).
Stenothermic: tolerating only a small range of temperature change.
Steppe: a sweep of unforested grasslands.
Stigma: the sticky tip of a pistil. Also: the pigment clusters that serve photosynthetic microbes as a light sensor.
Stochastic: randomly patterned
Stoma: small surface opening for gas exchange. Plants use stomata to take in carbon dioxide and emit oxygen and water.
Stone Mulch: placing stones near plants to water them with collected dew and to conserve water in the soil.
Storm Surge: the piling up of water by winds and low pressure weather (cyclones, hurricanes). They cause flooding when they rush onshore.
Stoss: a slope that faces into ice flow, wind, or running water. Opposite of lee.
Stream Order: a measure of stream size and branching, from first order streams (the largest) to twelfth.
Stress Proteins: proteins produced in response to environmental stress. Some of them ward off the hypothermia brought by extreme cold, for example.
Striations: parallel scratches or groves left by glacial abrasion.
Strip Mining: surface mining that strips off an entire surface layer (the overburden). Common consequences are eroded or denuded hillsides, devastated ecosystems, and toxic runoffs, especially of sulfur compounds from coal deposits. This pollutes not only the land but nearby water sources.
Subalpine: the highest elevation at which forests will grow.
Subduction: where one continental plate is pushed under another into the asthenosphere below. See Plate Tectonics.
Sublimation: a phase change from a solid into a gas state without any liquid state first. Example: dry ice turning directly into a vapor. Can also occur in reverse.
Subsidence: land drop. The decreased elevation can come from natural settling or from something done by humans (groundwater depletion, petroleum withdrawal).
Succession: the gradual replacement of one plant community by another. Brought about by changes in climate, in environment, or in the community (climatic succession, physiographic succession, biotic succession), and most frequently by erosion, dropping water levels, or invasion by another species. Succession due to external forces is allogenic, and autogenic when self-prompted. Overall, succession starts with pioneer species and proceeds to those more mature and longer lived (climax). Example: an empty lot taken over by weeds, then bushes, then flowering plants and finally trees.
Succession Planting: same crop, but planted a little at a time every one to three weeks or so to prevent them from all need harvesting at once.
Succulent: juicy, moisture-retaining plants like aloe, iceplant, cactus, agave, and yucca.
Sugar: an affectionate term of endearment.
Sucker: a plant shoot emerging from the root or lower stem. There's one born every minute.
Sunscald: the plant equivalent of sunburn.
Supercell: a severe thunderstorm with a steep, rotating updraft (see Mesocyclone). Supercells are likely candidates for producing tornados.
Surface Microlayer: the surface of water, where pollutants float and atmospheric gasses meet the sea.
Survival of the Fittest: originally a Darwinian hypothesis twisted around by philosopher Herbert Spencer to justify any desired might-makes-right form of social injustice as natural and inevitable. Very often “fittest” means the most cooperative--see Mutualism.
Suspension Feeder: an organism (e.g., a barnacle) that eats food particles suspended in water.
Sustainable: using resources without using them up.
Sustainable Society: a society that manages its politics, economies, industries, and population size without overwhelming ecosystems or depleting resources beyond their ability to recharge themselves. Alan Thein During’s basic definition of a sustainable society: “Each generation should meet its needs without jeopardizing the prospects for future generations to meet their own needs.” A less human-centered definition would include the ecosphere's needs as well.
Sustained Yield: a workable balance between taking and planting.
S-Wave (Secondary Wave: a seismic pulse that moves things up and down or side to side. It follows the P-wave.
Switching: when a predator changes from eating one species to another, usually in response to changing abundances. Tends to equalize competitive populations.
Symbiosis: a mutually beneficial relationship between two species, like the Hawaiian squid and the luminous bacteria it carries in its stomach. The bacteria gets a home, and the squid is camouflaged by the light.
Sympatric Speciation: the division of one species into two, but in the same geographical locale. Some biologists doubt it occurs. A possible example: the two species of freshwater three-spined sticklebacks that live in five lakes in British Columbia but do not mate with each other. Extensive competition may have driven them apart somehow.
Synapsid: a vertebrate whose skull has one pair of openings behind the eyes (like mammals and their close relatives).
Syncline: a downward-arching fold in rock. The opposite of an Anticline.
Systemic Insecticide: a chemical that makes a prey toxic to a predator. Often sprayed on plants.
Talik: an unfrozen patch of ground over, under, or inside a layer of permafrost.
Talus: a slope of rock debris formed at the base of a cliff.
Tapetum Lucidum: a reflecting membrane that reprocesses incoming photons. It makes the eyes of cats and other night animals shine.
Taproot: the primary root of a plant.
Tarn: a small mountain lake in a cirque.
Taxon: a classification category for a group of organisms (Cetaceans, Mammalia, Protista, etc.).
Taxonomy (see also Tree of Life): the classification of life, starting with Aristotle's attempts. Botanist Carl Linneaus worked out a system in 1735 whose primary categories are still in use. From largest to smallest, here is how we fit them:
- KINGDOM: Animalia (animals)
- PHYLUM: Chordata (with nerve chords)
- SUBPHYLUM: Vertebrata (and backbones)
- SUPERCLASS: Gnathostomata (and jaws for biting)
- CLASS: Mammalia (the young feed on mother's milk)
- ORDER: Primata (primates: five-fingered omnivores)
- SUBORDER: Haplorrhini (dry-nosed)
- FAMILY: Hominidae (erect, walking mammals)
- GENUS: Homo (humans and their close relatives, all now extinct but us)
- SPECIES: Homo sapiens (this two-name genus/species form is called binomial nomenclature)
Tea: a brew rich in soil nutrients. Examples are seaweed tea and compost tea. Many teas are foliar, meaning they can be sprayed directly on the leaves of plants.
Techno-Addiction: Chellis Glendinning’s term for the secondary cravings we use to fill our “original trauma” of separation from the natural world. She follows Paul Shepard in thinking of the search for identity as not only psychological, but ecological.
Temperature Inversion: warm air over cold.
Ten Percent Law: only about ten percent of the chemical energy available at one trophic level in a food chain is converted into a usable form for organisms at the next trophic level.
Tepal: a division of the outer whorl (perianth) of a flower (e.g., magnolias, lilies, and tulips) lacking clear differentiation into sepals and petals.
Tephra: rocky ejecta blown from a volcano.
Terracide: a largely unconscious but highly potent hatred for the Earth and, by extension, embodied, carnal living.
Thalloid: plants without leaves, stems, or roots, like duckweed, liverworts, and hornworts.
Thalweg: the deepest part of a waterway; also, a subterranean stream. Gewlath spelled backwards.
Thermal Pollution: a temperature rise that threatens an ecosystem, particularly one in which organisms breed or give birth.
Thermocline: a boundary marking a vertical change in temperature.
Thermokarst: high-altitude landscape holed pitted by selective permafrost thawing. Karst without the chemical weathering..
Third Law of Thermodynamics: an object cannot be cooled to a temperature of absolute zero by a finite number of steps. How about that.
Threshold Pollutant: a chemical that's dangerous only when concentrated, like sulphur dioxide.
Throughfall: scientific-sounding name for rain going through a forest canopy.
Throwaway Mentality: the belief that we can use up resources, throw away the remains, and move on to fresh ones. It is a holdover of the frontiersman mindset.
Tide: the periodic rise and fall of the ocean surface pulled on by gravity from moon and sun.
Till: glacial deposits: gravel, rocks, boulders.
Tilth: soil aggregation. "Good tilth" means it clumps properly for planting but is porous enough to let air in.
Timber Line: the highest elevation at which forests or stands of trees will grow. See Tree Line.
Tolerance, Ecological: examined close up, the term seems to mean "ability to put up with things that are harsh." The range of an organism's ability to do this is referred to as its ecological amplitude.
Tombolo: a sand belt or bar connecting an island with the mainland.
Topocosm: Theodore Gaster’s word for the entire locality--soils, plants, animals, everything, yesterday, today, and tomorrow--taken as an organism. The Neoplatonists called it the anima mundi (World Soul).
Topset Bed: the sedimentary surface of a delta.
Trade Winds: winds that blow toward the equator from the high-pressure horse latitudes, those bands of air above and below the equator that blow into the doldrums. From there it rises to the poles and returns. The trade winds blow from the northeast in the northern hemisphere (the Northeast Trades) and from the southeast in the southern (the Southeast Trades).
Transect: a path from which an observer records the apparent gradient of change in animal or plant species: which, where, numbers, densities.
Transpiration: evaporation of water from plant leaves. Plant sweat. Its activity depends on humidity: transpiration is higher in sunlight or wind, lower in fog or rain.
Tree Line: the highest elevation at which individual trees will grow.
Tree of Life: a classification of all living things from the kingdom level down to the species level. Formerly biology textbooks divided all living things into the five kingdoms described by Robert Whittaker in 1969; the current total, based more heavily on RNA/DNA research, is three, now called domains (Carl Woese, 1990) but leaving out the viruses:
- Archaea (ancient, bacterialike animals that live in extreme environments)
- Bacteria (the great natural chemists of Earth)
- Eukarya (everyone else: fungi, protists, animals and plants)
Tributary: a stream channel that branches back toward its source. The opposite of a Distributary.
Trophic: nutritive; see Food Chain and Food Web.
Tropic of Cancer: latitude of 23.5° North. The northernmost reach of the sun's declination. See Solstice.
Tropic of Capricorn: latitude of 23.5° South. The southernmost reach of the sun's declination.
Tropophyte: a plant that adapts its requirements to climate extremes, like a deciduous tree dropping its leaves in winter and growing them back in spring.
Tuber: a buried stem that stores nutrients. An enlarged rhizome.
Tundra: an arctic or subarctic treeless plain with frozen subsoil and small growth: some grasses, dwarf shrubs, lichens, mosses, sedges, and herbs. Often found at high latitudes between the tree line and the snow line.
T-Value (T-Level): a 1-5 scale of soil loss tolerance: the average maximum soil loss, in tons per acre per year, that still allows the current production level.
Ultrastructure (Fine Structure): those structural details of an organism visible only to an electron microscope.
Understock: the segment of plant to which a graft is joined.
Understory: the trees and other vegetation living below a forest canopy.
Ungulates: hoofed animals.
Uniformitarianism: the well-substantiated hypothesis that the Earth and its organisms developed primarily from gradual processes and conditions rather than sudden Biblical Flood-style catastrophes.
Upwelling: the upward flow of cold, nutrient-rich water toward the ocean surface as currents or seasonal winds draw warmer water away from a coast. Phytoplankton that feed in upwellings often support huge fish populations.
Urban Heat Island: a bubble of heat hung over a metropolis not only by cars, industrial plants, business parks, and other such structures, but by paved areas devoid of vegetation. Cities then grow warmer than the surrounding land.
Variegated: plant pigmentation that creates multicolored foliage.
Vascular: networks of channels that transport nutrients, fluids, and wastes. The circulatory system is an example.
Varve: a thin deposit of sediment found on a lake bottom. Because its thickness fluctuates annually, its layers disclose information about the lake's geological past.
Vector: a disease-carrying organism.
Ventifact: a piece of stone blasted smooth by windblown sand particles.
Vertebrate: an animal with a backbone. Most large animals are vertebrates. They probably evolved from a wormlike ancestor that turned upside down (upside-down catfish do this today). See Invertebrate.
Vicariance: the evolution of a new species from a group separated from the original species by a geographic barrier.
Virus: a protein-coated fragment of DNA or RNA that infects a host cell in order to reproduce.
Volatile Organic Compounds (VOCs): a component of photochemical smog consisting of organic molecules released into the atmosphere from household products like paint, solvents, aerosols, cleaners, and (oddly enough) air fresheners.
Wallace Effect: females attracted to males most like themselves breed offspring more like themselves and less like the members of any subspecies, a tendency that eventually creates a separate species.
Wallace’s Realms: six geographical animal realms: Nearctic, Palaearctic, Neotropical, Ethiopian, Oriental, and Australasian. They roughly outline the breakup of the supercontinent Pangaia into continents on which different kinds of fauna lived and evolved.
Washover Fan: the fan-shaped sedimentary deposits left when storm surges wash over barrier islands, thereby transferring sand from one part of the island to another.
Waste Treatment Pond: a shallow lagoon or pond in which agricultural manure and other wastes are broken down by microscopic organisms.
Water Budget: the balance of all water moving into and out of a specified area in a specified period of time.
Water Table: the pooling of groundwater on top of a bedrock layer. This pooling holds 95% of the world's total supply of freshwater.
Watershed: the region drained by a stream or river.
Weed: a plant growing where it is not wanted.
Weir: a barrier or fence in water that diverts something: fish, water flow, erosive material.
Westerlies: variable mid-latitude winds that often bring moisture.
Wetland: a wet land; a bog, fen, marsh, estuary. Wetlands are rich in nutrients, unique in ecosystems, and hospitable to many forms of life, including birds on long flyways. They also filter pollutants out of the water and ease the force of passing floods. The Florida Everglades performed these and other ecologically beneficial activities until 1905, when a governor with the remarkably apt name of Napoleon Bonaparte Broward led the push to dredge, fill, dig, and canal; the resulting floods, stagnation, salinization, fish kills, bird deaths, agricultural runoffs, drought, groundwater depletion, and fire potential have not yet been brought under control. In the United States, farmers were encouraged to allow acreage for wetlands until the Bush Administration not only ended the incentives, but eased regulations in filling in existing wetlands. See Estuarine Zone.
Wilderness Effect: Robert Greenway’s term for the impact of the wilderness experience on the psyche: the gradient goes from none to “a complete blowout of one’s usual programs for processing reality.” Somewhere between these points is where information processing switches from culture-dominated to nature-dominated.
Xerophytes: organisms that live in dry areas.
Xylem: woody tissue that transports water and nutrients upward from the roots.
Yardang: rock streamlined by wind erosion.
Yazoo Tributary: a small tributary stopped by levees (embankments) from joining the main channel.
Zero Population Growth (ZPG): when birth rate (plus immigration) equals the death rate (plus emigration), resulting in an ecologically stable number of organisms.
Zoonotic Diseases: diseases transmissible from animals to humans. Ebola, tuberculosis, and rabies are examples.
Zooplankton: plankton that do not produce their own food, as phytoplankton do. In size they fall between phytoplankton and larger organisms like fish.
Zygote: a fertilized egg.
The world opened in the thickets of the dark. The wild grapes would soon ripen on the vines. The burrowing ones were emerging. Horned owls sat in the treetops. Mice scurried here and there. Skunks, fox, the slow and holy porcupine, all were passing by this way. The young of the solitary bees were feeding on pollen in the dark. The whole world was a nest on its humble tilt, in the maze of the universe, holding us. -- Linda Hogan
© by Craig Chalquist, 2004-2009.