AP Exam Definitions

abiotic
nonliving.
acid
a substance that releases hydrogen ions (protons) in water. acids have a sour taste and turn blue litmus paper red.
acid decomposition
a type of air pollution that includes acid that falls from the atmosphere as precipitation or as dry acidic particles.
acid rain
rainfall made sufficiently acidic by atmospheric pollution that it causes environmental harm, typically to forests and lakes. The main cause is the industrial burning of coal and other fossil fuels, the waste gases from which contain sulfur and nitrogen oxides, which combine with atmospheric water to form acids.
acidic solution
Any water solution that is acidic (pH less than 7) or has more hydrogen ions (H+) than hydroxide ions (OH-).
adaptation
an evolutionary modification that improves the chances of survival and reproductive success of a population in a given environment.
adaptive radiation
the evolution of a large number of related species from an unspecialized ancestral organism.
advanced sewage treatment
The combination of primary and secondary treatment removes most of the organic matter in sewage and thus lowers the BOD. However, most of the nitrogen and phosphorus in sewage remains in the effluent from secondary treatment. These inorganic nutrients can cause eutrophication of surface water receiving the effluent causing blooms of algae. To avoid this, a few communities add a third stage of treatment called tertiary or advanced waste treatment.
aerobic respiration
the process by which cells use oxygen to break down organic molecules into waste products wish the release of energy that can be used for biological work.
affluenza
a painful, contagious, socially transmitted condition of overload, debt, anxiety and waste resulting from the dogged pursuit of more.
age structure
the number and proportion of people at each age in a population.
agricultural revolution
a period of agricultural development between the 18th century and the end of the 19th century, which saw a massive and rapid increase in agricultural productivity and vast improvements in farm technology.
agroforestry
forestry and agricultural techniques that are used to improved degraded areas; in agroforestry, trees and crops are often planted together.
air pollution
various chemicals present in high enough levels in the atmosphere to harm humans, other animals, plants, or materials. EXCESS NOISE AND HEAT ARE ALSO CONSIDERED AIR POLLUTION.
albedo
the proportional reflectance of earth’s surface; glaciers and ice sheets have high albedos and reflect most of the sunlight hitting their surfaces, whereas the ocean and forests have low albedos.
alley cropping
A method of planting in which rows of a crop are sown between rows or hedges of nitrogen-fixing plants, the roots of which enrich the soil.
altitude
the height of a thing above sea level.
anaerobic respiration
the process of synthesizing ATP using the electron transport chain, with inorganic molecules other than oxygen used as a final electron acceptor.
ancient forest
type of forest that has attained great age and so exhibits unique biological features
anthropocentric
the belief that humans must be considered at the center of, and above any other aspect of, reality.
aquaculture
the rearing of aquatic organisms, either freshwater or marine, for human consumption.
aquatic life zone
refers to those zones under the water, whether it be sea, river or larkes, where aquatic life is present. These zones are characterized by aquatic ecosystem, where communities of organisms live. It has two types which are marine ecosystem and freshwater ecosystem.
aquifer
the underground caverns and porous layers of underground rock in which groundwater is stored.
arable land
an agricultural term, meaning land that can be used for growing crops.
area strip mining
Area mining is normally carried out on flat terrain. It starts with a trench in the overburden to expose part of the coal seam. The trench is extended to the boundary limit in the strike direction.

After coal removal, a second cut is made parallel to the first one, and the overburden material from this cut is placed in the void of the first cut. The process is repeated in successive parallel cuts until continued surface mining is uneconomical.

arid
(of land or a climate) having little or no rain; too dry or barren to support vegetation.
artificial selection
describes intentional breeding for certain traits, or combination of traits.
atmosphere
the gaseous envelope surround earth.
atmospheric pressure
ometimes defined as the force per unit area exerted against a surface by the weight of air above that surface at any given point in the Earth’s atmosphere.
autotroph
an organism that produces complex organic compounds from simple inorganic molecules using energy from light or inorganic chemical reactions. (producer)
background extinction
the continuous, low-level extinction of species that has occurred throughout much of the history of life.
bacteria
unicellular, prokaryotic microorganisms. most bacteria are decomposers, but some are autotrophs, and some are parasites.
barrier islands
A long, relatively narrow island running parallel to the mainland, built up by the action of waves and currents and serving to protect the coast from erosion by surf and tidal surges.
benthos
bottom-dwelling marine organisms that fix themselves to one sport, burrow into the sand, or simply walk about on the ocean floor.
biocentric preservationist
a person who believes in protecting nature because all forms of life deserve respect and consideration.
biodegradable
a chemical pollutant decomposed by organisms or by other natural processes.
biodiversity
the number and variety of organisms; includes genetic diversity, species richness, and ecosystem diversity.
biogeochemical cycle
a pathway by which a chemical element or molecule moves through both biotic (biosphere) and abiotic (lithosphere, atmosphere, and hydrosphere) compartments of Earth. (nutrient cycle)
biological community
describes all the interacting organisms living together in a specific habitat (or biotope)
biological diversity
the number and variety of organisms. (biodiversity)
biological evolution
any genetic change in a population that is inherited over several generations. These changes may be small or large, noticeable or not so noticeable.
biological oxygen demand (BOD)
the amount of oxygen needed by microorganisms to decompose the organic material in a given volume of water.
biomass
a quantitative estimate of the total mass, or amount, of a living material. often expressed as the dry weight of all the organic material that comprises organisms in a particular ecosystem.
biome
a large,relatively distinctterrestria regioin characterized by a similar climate, spoil, plants, and animals, regardless of where it occurs on earth; because it is so large in area, a biome encompasses many interacting ecosystems.
biosphere
all of earth’s organisms and their interactions with eachother, the land, the water, and the atmosphere.
biotic
living.
biotic pollution
the accidental or intentional introduction of a foreign, or exotic, species into an area where it is not native.
biotic potential
the maximum reproductive capacity of a population under optimum environmental conditions.
birth rate
the number of births per 1000 people per year.
bitumen
mixture of organic liquids that are highly viscous, black, sticky, entirely soluble in carbon disulfide, and composed primarily of highly condensed polycyclic aromatic hydrocarbons. OIL
breeder nuclear fission reactor
a type of nuclear fission in which nonfissionable U-238 is converted to fisssonable P-239
broadleaf deciduous plants
plants that shed their leaves and change colors
broadleaf evergreen plants
those that do not change color or lose leaves
buffer
an aqueous solution consisting of a mixture of a weak acid and its conjugate base or a weak base and its conjugate acid.
calorie
a unit of heat energy; the amount of heat required to raise 1g of water 1 degrees C
carbon cycle
the worldwide circulation of carbon from the abiotic environment into organisms and back into the abiotic environment.
carbon oxides
Carbon forms two important gases with oxygen: carbon monoxide, CO, and carbon dioxide, CO2.
carnivore
an animal that feeds on other animals; flesh-eater.
carrying capacity (k)
the maximum number of individuals of a given species that a particular environment can support sustainably (long term), assuming there are no changes in the environment.
chain reaction
a reaction maintained because it forms as products the very materials that are used as reactants in the reaction.
chemical evolution
the process by which increasingly complex elements, molecules? and compounds? developed from the simpler chemical elements that were created in the Big Bang.
chemosynthesis
the biological process by which certain bacteria take inorganic compounds from their environment and use them to obtain energy and make carbohydrate molecules.
chronic undernutrition
severe malnutrition and lack of nutrients.
clear-cutting
a forest management technique that involves the removal of all trees from an area at a single time.
climate
the average weather conditions that occur in a place over a period of years.
coal
a black combustible solid found in earth’s crust; formed from the remains of ancient plants that lived millions of years ago and used as a fuel.
coal gasification
the technique of producing a synthetic gaseous fuel (such as methane) from solid coal.
coal liquefaction
the process by which solid coal is used to produce a synthetic liquid fuel similar to oil.
coastal wetland
marshes, bays, tidal flats, and swamps that are found along a coastline.
coastal zone
the interface between the land and water.
coevolution
the interdependent evolution of two mor more species that occurs as a result of their interactions over a long period.
cold front
the leading edge of a cooler and drier mass of air, replacing (at ground level) a warmer mass of air.
commercial extinction
depletion of the population of a commercially important species to the point that it is unprofitable to harvest.
commercial inorganic fertilizer
manufactured from inorganic chemical compounds
community
an association of different species living together at the same time in a defined habitat with some degree of mutual interdependence.
compost
a natural soil and humus mixture that improves soil fertility and soil structure.
condensation nuclei
small particles or aerosol upon which water vapor attaches to initiate condensation. Dust particulates, sea salt, sulfur and nitrogen oxide aerosols serve as common condensation nuclei.
coniferous evergreen plants
woody trees or shrubs that bear needle-like leaves that do not change color or fall.
coniferous trees
any of a group of woody trees or shrubs that bear needle-like leaves and seeds in cones.
conservation
the sensible and careful management of natural resources.
conservation biology
a multidisciplinary science that focuses on the study of how humans impact organisms and on the development of ways to protect biological diversity.
conservationist
a person who supports the conservation of natural resources.
conservation-tillage farming
a method of cultivation in which residues from previous crops are left in the soil, partially covering it and helping to hold it in place until the newly planted seeds are established.
consumer
an organism that cannot synthesize its own food from inorganic materials and therefore must use the bodies of other organism as sources of energy and body-building materials.
contour farming
plowing that matches the natural contour of the land, that is, the furrows run around rather than up and down a hill; lessens erosion, as on a hillside.
contour strip mining
mining along a mountains contour using strip mining techniques.
controlled burning
a technique sometimes used in forest management, farming, prairie restoration or greenhouse gas abatement.
conventional-tillage farming
the traditional method of cultivation in which the soil is broken up by the plowing before seeds are planted.
coral reef
structure built from accumulated layers of calcium carbonate (CaCO3); found in warm, shallow sea water.
core
the center of the earth.
cost-benefit analysis
a mechanism that helps policy-makers make decisions about environmental issues. compares estimated costs of a particular action with potential benefits that would occur if that action were implemented.
crop rotation
the planting of different crops in the same field over a period of years. crop rotation reduces mineral depletion of the soil because the mineral requirements of each crop vary.
crown fire
a forest fire that advances with great speed jumping from crown to crown ahead of the ground fire.
crude birth rate
number of births per 1000 people per year.
crude death rate
the number of deaths per 1000 people per year.
crude oil
a thick, yellow to black, flammable liquid hydrocarbon mixture found in earth’s crust.
cultural eutrophication
overnourishment of an aquatic ecosystem by nutrients such as nitrates and phosphates.
death rate
number of deaths per 1000 people per year
debt-for-nature swap
the cancelllation of part of a country’s foreign debt in exchange for their agreement to protect certain lands from detrimental development.
deciduous plants
plants of which the leaves fall off seasonally.
decomposer
a heterotroph that breaks down organic material and uses the decomposition products to supply it with energy.
deductive reasoning
reasoning that operates from generalities to specifics and can make relationship among data more apparent.
deep ecology environmental worldview
an understanding of our place in the world based on harmony with nature, a spiritual respect for life, and the belief that humans and all other species have an equal worth.
deforestation
the temporary or permanent clearance of large expanses of forests for agriculture or other uses.
degradable pollutant
a pollutant that can be broken down by the environment over time.
degree of urbanization
amount of urbanization in an environment.
demographic transition
the process whereby a country moves from relatively high birth and death rates to relatively low birth and death rates.
depletion time
amount of time for a resource to be depleted.
desalination
the removal of salt from ocean or brackish water.
desert
arid land that receives little rainfall.
desertification
degradation of once-fertile rangeland into nonproductive desert. caused partly by soil erosion, deforestation, and overgrazing.
detritivore
an organism that consumes fragments of dead organisms. (crabs, earthworms)
detritus
organic matter that includes dead organisms and wastes.
detritus feeder
a detritivore.
deuterium (D; hydrogen-2)
an isotope of hydrogen that contains one proton and one neutron per atom.
developed country
countries that have a high level of development according to some criteria.
developing country
a country not highly industrialized and characterized by a high fertility rate, high infant mortality rate, and low per-capita income.
dieback
common symptom or name of disease, especially of woody plants, characterized by progressive death of twigs, branches, shoots, or roots, starting at the tips.
differential reproduction
individuals within a species compete with each other for mates, and those that are best equipped to succeed in this struggle will produce the most offspring.
discount rate
annual interest divided by the capital including that interest
dissolved oxygen (DO) content
oxygen dissolved in water. very important to aquatic life.
distribution
the dispersal of a thing.
domesticated species
adapted to humans.
doubling time
the amount of time it takes for a population to double in size, assuming that its current rate of increase doesn’t change.
drainage basin
a land area that delivers water into a stream or river system.
dredging
an excavation activity or operation usually carried out at least partly underwater, in shallow seas or fresh water areas with the purpose of gathering up bottom sediments and disposing of them at a different location.
drift-net fishing
a fishing technique where nets, called drift nets, are allowed to drift free in a sea or lake.
drought
an extended period of months or years when a region notes a deficiency in its water supply.
durability
the ability to endure.
earth-centered environmental worldview
earth viewed as a priority.
ecofeminist environmental worldview
feminist.
ecological diversity
refers to the diversity of a place at the level of ecosystems.
ecological efficiency
The ability of the organisms at one trophic level to convert to their own use the potential energy supplied by their foodstuff.
ecological footprint
the average amount of land and ocean needed to supply an individual with food, energy, water, housing, transportation and waste removal.
ecological niche
the relational position of a species or population in an ecosystem.
ecological restoration
the study of renewing a degraded, damaged, or destroyed ecosystem through active human intervention.
ecologist
tudy the relationships of living things to their environment and with each other, and examine the effects of a wide range of factors such as population size, rainfall, temperature, forest fires and major construction projects.
ecology
a discipline of biology that studies the interrelationships between organisms and among organisms and their environment.
economic depletion
depletion of economic resources.
economic development
the development of economic infrastructure.
economic growth
the expansion of an economy.
economic resources
resources used within an economy.
economic system
a system of economics.
economy
the realized social system of production, exchange, distribution, and consumption of goods and services of a country or other area. A given economy is the end result of a process that involves its technological evolution, civilization’s history and social organization, as well as its geography, natural resource endowment, and ecology, among other factors.
ecosphere
a closed ecosystem.
ecosystem
the interacting system that encompasses a community and it nonliving, physical environment. in an ecosystem, all of the biological, physical, and chemical components of an area form a complex interacting network of energy flow and materials cycling.
electromagnetic radiation
a ubiquitous phenomenon that takes the form of self-propagating waves in a vacuum or in matter.
elevation
height above a fixed reference point, often the mean sea level.
emigration
a type of dispersal in which individuals leave a population and thus decrease its size.
endangered species
a species whose numbers are so severely reduced that it is in imminent anger of becoming extinct in all or a significant range.
endemic species
localized, native species that are not found anywhere else in the world.
energy
the capacity or ability to do work.
energy efficiency
using less energy to accomplish the same task.
energy productivity
measures the output and quality of goods and services generated with a given set of inputs.
energy quality
the contrast between different forms of energy, the different trophic levels in ecological systems and the propensity of energy to convert from one form to another.
environment
all external condition, both abiotic and biotic, that affect an organism or group of organisms.
environmental degradation
the degradation of the environment.
environmental ethics
a field of applied ethics that considers the moral basis of environmental responsibility and how fart his responsibility extends; environmental ethicsts try to determine how we humans should relate to nature.
environmental movement
the movement of environmental awareness.
environmental resistance
limits set by the environment that prevent organisms from reproducing indefinitely at their biotic potential.
environmental revolution
part of the environmental movement of awareness and advocacy.
environmental science
the interdisciplinary study of how humanity interacts with other organisms and the nonliving physical environment.
environmental wisdom worldview
environmental knowledge.
environmental worldview
a worldview that helps us make sense of how the environment works, our place in the environment, and right and wrong environmental behaviors.
environmentalism
a broad philosophy and social movement centered on a concern for the conservation and improvement of the environment.
environmentalist
an environmental advocate.
environmentally sustainable economic development
economic development with the environment in mind.
environmentally sustainable society
a society that operates in a sustainable manner.
environmental protection agency (EPA)
an agency that protects the environment through a series of laws.
estuary
a coastal body of water that connects to the ocean, in which fresh water from a river mixes with saltwater from the ocean.
euphotic zone
the upper reaches of the pelagic environment, from the surface to a maximum depth of 150m in the clearest open ocean water; sufficient light penetrates the euphotic zone to support photosynthesis.
eutrophic lake
a lake enriched with nutrients such as nitrates and phosphates and consequently overgrown with plants or algae; little dissolved oxygen.
eutrophication
the enrichment of a lake, estuary, or slow flowing stream by nutrients that cause increased photosynthetic productivity.
evaporation
the conversion of water from a liquid to a vapor.
even-aged management
the application of a combination of management actions, which results in a timber stand comprised of trees that are the same age.
evergreen plants
plants that do not shed leaves or change colors.
evolution
the cumulative genetic changes in populations that occur during successive generations.
exhaustible resource
a resource that can be used up if not used with care.
exponential growth
the accelerating population growth that occurs when optimal conditions allow a constant rate of increase over a period of time.
external benefit
a benefit that someone gains because of someone else’s action, outside of any market transaction between them.
external cost
a harmful side effect of production of consumption of a product that his borne by people not directly involved in the market exchange for the product; an external cost is usually not reflected in a product’s price.
externalities
an externality or spillover of an economic transaction is an impact on a party that is not directly involved in the transaction.
extinction
the elimination of a spices from Earth; occurs when the last individual member of a species dies.
family planning
providing the services, including information about birth control methods, to helps people have the number of children they want.
famine
widespread starvation caused by a drastic shortage of food.
feedback loop
the causal path that leads from the initial generation of the feedback signal to the subsequent modification of the event.
feedlot
type of Confined Animal Feeding Operation (CAFO) (also known as “factory farming”) which is used for finishing livestock, notably beef cattle, prior to slaughter.
fermentation
is the process of deriving energy from the oxidation of organic compounds, such as carbohydrates, using an endogenous electron acceptor, which is usually an organic compound.
fertility
the natural capability of giving life.
fertilizer
a material containing plant nutrients, such as nitrates, phosphates, and potassium, that is put on the soil to enhance plant growth.
first law of thermodynamics
energy cannot be created or destroyed, although it can be transformed from one form to another.
fish farming
the principle form of aquaculture.
fish ranching
ranching of fish.
fishery
an entity engaged in raising and/or harvesting fish, which is determined by some authority to be a fishery.
flood plain
the area bordering a river that is subject to flooding.
flyway
an established route that ducks, geese, and shorebirds follow during their annual migrations.
food chain
the successive series of organism through which energy flows in an ecosystem.
food web
a complex interconnection of all the food chains in an ecosystem.
forest
an area with a high density of trees.
fossil fuel
combustible deposits in earth’s crust.
free-access resource
resource that can be accessed freely.
freshwater life zones
freshwater biomes.
front
a boundary separating two masses of air of different densities, and is the principal cause of meteorological phenomena.
frontier environmental worldview
the attitude of seeing natural resources as being inexhaustible.
frontier science
scientific research performed on location.
full cost accounting
the process of evaluating and presenting to decision makers the relative benefits and costs of various alternatives.
functional diversity
diversity that proves to be beneficial to a population.
fundamental niche
the potential ecological niche that an organism could have if there were no competition from other species.
fungicide
a toxic chemical that kills fungi.
game species
species used as wild game.
gangue
the commercially worthless mineral matter associated with economically valuable metallic minerals in a deposit
gene mutation
the mutation of a gene.
gene pool
indicates genetic diversity.
gene splicing
the splitting of a gene.
generalist species
able to thrive in a wide variety of environmental conditions and can make use of a variety of different resources (for example, a heterotroph with a varied diet).
genes
a segment of DNA that serves as a unit of hereditary information.
genetic adaptation
the change of a gene over time to benefit the organism.
genetic diversity
biological diversity that encompasses the genetic variety among individuals within a single species.
genetic engineering
the ability to take a specific gene from one cell and place it into another cell where it is expressed.
genetically modified organism (GMO)
an organism that has been genetically modified.
geographic isolation
influences evolution.
globalization
the process of transformation of local or regional phenomena into global ones.
grassland
an area that is largely covered in short, scrubby grasses.
green manure
a type of cover crop grown primarily to add nutrients and organic matter to the soil.
green revolution
the period of time during the 20th century when plant scientists developed genetically uniform, high-yielding varieties of important food crops such as rice and wheat.
greenhouse effect
the natural global warming of our atmosphere caused by the presence of carbon dioxide and other greenhouse gases, which trap the sun’s radiation.
greenhouse gases
the gases that absorb infrared radiation, which include carbon dioxide, methane, nitrous oxide, chlorofluorocarbons, and tropospheric ozone, all of which are accumulating in the atmosphere as a result of human activities.
gross domestic product (GDP)
one of the measures of national income and output for a given country’s economy.
gross primary productivity
the rate at which energy accumulates in an ecosystem (as biomass) during photosynthesis.
ground fire
a fire that burns low to the ground.
groundwater
the supply of fresh water under earth’s surface.
gully erosion
the removal of soil along drainage lines by surface water runoff.
habitat
the local environment in which an organism, population, or species lives.
half-life
half the time it takes for a radioactive element to decay.
heat
any transfer of energy from one body or system to another due to a difference in temperature.
herbicide
a toxic chemical that kills plants.
herbivore
an animal that feeds on plants or algae.
heterotroph
an organism that uses organic substrates to get its chemical energy for its life cycle.
high-input agriculture
modern agricultural methods that require a large capital input and less land and labor than traditional methods.
high-quality energy
electricity.
high-quality matter
is fairly easy to extract and is concentrated; solids, liquids, gases.
high-throughput economy
i dont know.
high-waste economy
wasteful economic practices.
HIPPO (Habitat destruction, Invasive species, Pollution, Population, and Overharvesting)
all bad.
human capital
refers to the stock of skills and knowledge embodied in the ability to perform labor so as to produce economic value.
human resources
resources available for human use and consumption.
human-centered environmental worldviews
human life emphasis. selfish.
humus
black or dark brown decomposed organic material.
hunter-gatherers
hunting and gathering food.
hydrocarbons
a diverse group of organic compounds that contain only hydrogen and carbon.
hydrologic cycle
the water cycle, which includes evaporation, precipitation, and flow to the seas. supplies terrestrial organisms with a continual supply of fresh water.
hydrosphere
all water biomes.
identified resources
known and viable resources.
immigration
a type of dispersal in which individuals enter a population and thus increases its size.
inductive reasoning
reasoning that uses specific examples to draw a general conclusion or discover a general principle.
industrial smog
the traditional, long-type smoke pollution, which consists principally of sulfur oxides and particulate matter.
industrialized agriculture
same as high-input agriculture.
infant mortality rate
the number of infant deaths per 1000 live births.
infiltration
the process by which water on the ground surface enters the soil.
information and globalization revolution
the increased interconnectivity of the world through outlets such as the internet.
inherent value
obvious value?
inland wetland
a wetland away from a coast or river.
inorganic compounds
considered to be of a mineral, not biological, origin.
inorganic fertilizer
a nutrient such as phosphate or nitrate that stimulates pant or algal growth
input pollution control
i don’t know.
insecticide
a toxic chemical that kills insects.
instrumental value
the value of objects, both physical objects and abstract objects, not as ends-in-themselves but a means of achieving something else.
integrated pest management (IPM)
a pest control strategy that uses a variety of complementary strategies including: mechanical devices, physical devices, genetic, biological, cultural management, and chemical management.
intercropping
a form of intensive subsistence agriculture that involves growing several crops simultaneously on the same field.
internal cost
the actual cost.
interplanting
planting a variety of species on the same field.
intertidal zone
the shoreline area between the low tide mark and the high tide mark.
intrinsic rate of increase (r)
the exponential growth of a population that occurs under constant conditions.
intrinsic value
value within.
inversion
a deviation from the normal change of an atmospheric property with altitude.
ionizing radiation
radiation that contains enough energy to eject electrons from atoms, forming positively charged ions.
isotopes
an alternate form of the same element that has a different atomic mass.
j-shaped curve
where a curve initially falls, but then rises to higher than the starting point.
kerogen
a mixture of organic chemical compounds that make up a portion of the organic matter in sedimentary rocks.
kilocalorie (kcal)
a unit of heat energy equivalent to the energy required to raise the temperature of 1 kilogram of water by 1 degree C.
kinetic energy
the energy of a body that results from its motion.
k-selected species
a reproductive strategy in which a species typically has a large body size, slow development, long life spand, and does not devote a large proportion of its metabolic energy to the production of offspring.
k-strategists
big like an elephant.
land degradation
the degradation of land and its resources.
land-use planning
the process of deciding the best uses for undeveloped land in a given area.
latitude
the distance, measured in degrees from north or south, from the equator.
law of conservation of matter
matter can be neither created nor destroyed.
law of conservation of energy
energy can be transferred but never destroyed.
leaching
the process by which dissolved materials are washed away or filtered down through the various layers of the soil.
less developed country (LDC)
a developing country with a low level of industrialization, a very high fertility rate, a very high infant mortality rate, and a very low per-capita income.
life cycle cost
the total cost of ownership over the life of an asset
life expectancy
the expected duration of an organism’s lifetime.
life-centered environmental worldview
life of all kinds viewed as being valuable.
limiting factor
a factor that limits the growth of a population; such as food or climate.
limiting factor principle
limiting factors keep species from growing exponentially.
linear growth
grows by the same amount in each time step. steady rate of increase.
lipids
a diverse group of organic molecules that are metabolized by cellular respiration to provide the body with a high level of energy; commonly called fats and oils.
liquified natural gas
natural gas that is liquified for transport purposes.
liquified petroleum gas
a mixture of liquified propane and butane. stored in pressurized tanks.
lithosphere
the soil and rock of earth’s crust.
loams
an idea agricultural soil that has an optimum combination of different soil particle sizes: approx. 40% each of sand and silt, and about 20% of clay.
logistic growth
The initial stage of growth is approximately exponential; then, as saturation begins, the growth slows, and at maturity, growth stops.
low-input agriculture
un-mechanized. sustainable.
low-quality energy
heat.
low-quality matter
salt solutions, emissions.
low-throughput economy
i have no idea.
low-waste economy
an economy that is clean in its operation and function.
macroevolution
scale of analysis of evolution in separated gene pools.
malnutrition
a condition caused when a person does not receive enough specific essential nutrients in the diet.
mangrove swamps
swamps of mangrove trees that grow along many tropical coasts.
manufactured capital
(or human-made) captial is what is traditionally considered as capital: produced assets that are used to produce other goods and services.
manufactured resources
artificial resources made for humans.
marginal benefit
Increase or decrease in an activity’s overall benefit caused by a unit increase or decrease in the level of that activity, all other factors remaining constant.
marginal cost
the change in total cost that arises when the quantity produced changes by one unit.
mass depletion
a largescale depletion of a resource(s)
mass extinction
the extinction of numerous species during a relatively short period of geological time.
mass transit
mass transportation
material efficiency
a description or metric which expresses the degree in which usage of raw materials, construction projects or physical processes are used or carried out in a manner which consumes, incorporates, or wastes less of a given material compared to previous measures.
matter-recycling economy
an economy that recycles its own matter.
maximum sustainable yield
the largest yield (or catch) that can be taken from a species’ stock over an indefinite period.
megacity
a city with more than 10 million inhabitants.
meltdown
the melting of a nuclear reactor vessel.
mesotrophic lake
lakes with an intermediate level of productivity, greater than oligotrophic lakes, but less than eutrophic lakes.
metabolism
the set of chemical reactions that occur in living organisms in order to maintain life.
metropolitan area
a large population center consisting of a large metropolis and its adjacent zone of influence, or of more than one closely adjoining neighboring central cities and their zone of influence.
microevolution
the occurrence of small-scale changes in allele frequencies in a population, over a few generations, also known as change at or below the species level.
micronutrients
nutrients needed for life in small quantities.
microorganisms
an organism that is microscopic (usually too small to be seen by the naked human eye).
migration
directed, regular, or systematic movement of a group of objects, organisms, or people.
mineral resource
any undiscovered mineral deposits or known deposits of low-grade ore that are currently unprofitable to extract.
minimum viable population (MVP)
a lower bound on the population of a species, such that it can survive in the wild.
minimum-tillage farming
The use of cropping systems with minimal tillage is usually desirable, because intensive tillage tends to break down soil structure.
model
a formal statement that describes a situation and can be used to understand the present or predict the future course of events.
monoculture
the cultivation of only one type of plant over a large area.
monsoons
a seasonal prevailing wind that lasts for several months.
more developed country
a developing country with a medium level of industrialization, a high fertility rate, a high infant mortality rate, and a low per-capita income.
mountaintop removal
a form of surface mining that involves extreme topographic change to the summit or summit ridge of a mountain.
multiple use
a resource that has multiple, alternate uses.
mutation
a change in the DNA of an organism.
natural capital
earth’s resources and processes that sustain living organisms.
natural gas
a mixture of gaseous hydrocarbons (primarily methane) that occurs, often with oil deposits, earth’s crust.
natural greenhouse effect
the natural occurence of the greenhouse effect.
natural law
a theory that posits the existence of a law whose content is set by nature and that therefore has validity everywhere.
natural rate of extinction
the natural rate of extinction amongst species.
natural recharge
The replenishment of groundwater storage from naturally-occurring surface water supplies such as precipitation and stream flows.
natural resources
resources made naturally available.
natural selection
the tendency of organisms that posses favorable adaptations to their environment to survive and become the parents of the next generation.
negative feedback loop
occurs when the output of a system acts to oppose changes to the input of the system; with the result that the changes are attenuated.
nekton
relatively strong-swimming aquatic organisms such as fish and turtles.
net energy
i don’t know.
net primary productivity
energy that remains in an ecosystem after cellular respiration has occured.
niche
the totality of an organism’s adaptations, its use of resources, and the lifestyle to which it is fitted.
nitric acid (HNO3)
a highly corrosive and toxic strong acid that can cause severe burns.
nitrogen cycle
the worldwide circulation of nitrogen from the abiotic environment into organism and back into the abiotic environment.
nitrogen fixation
the conversion of atmospheric nitrogen (N2) to ammonia (NH3) by nitrogen-fixing bacteria and cyanobacteria.
nitrogen oxides
refers to any binary compound of oxygen and nitrogen, or to a mixture of such compounds.
noise pollution
a loud or disagreeable sound, particularly when it results in physiological or psychological harm.
nodegradable pollutant
a pollutant that cannot be broken down or decomposed.
non-ionizing radiation
any type of electromagnetic radiation that does not carry enough energy per quantum to ionize atoms or molecules — that is, to completely remove an electron from an atom or molecule.
non-persistent pollutant
a pollutant that does not persist.
nonpoint source pollution
pollutants that enter bodies of water over large areas rather than being concentrated at a single point of entry.
nonrenewable resource
natural resources that are present in limited supplies and are depleted by use.
no-till farming
a method of conservation tillage that leaves both the surface and subsurface soil undisturbed.
nuclear change
involves changes in nuclear structure, such as fission (splitting) of a nucleus or an atom, or fusion (combining) of neutrons and protons to form heavier atoms. This involves about 1,000,000 times as much energy as a chemical change.
nuclear energy
the energy released from the nucleus of an atom in a nuclear reaction or during radioactive decay.
nuclear fission
a nuclear reaction in which the nucleus of an atom splits into smaller parts, often producing free neutrons and lighter nuclei, which may eventually produce photons (in the form of gamma rays).
nuclear fussion
he process by which multiple like-charged atomic nuclei join together to form a heavier nucleus.
nutrient
a chemical that an organism needs to live and grow or a substance used in an organism’s metabolism which must be taken in from its environment.
nutrient cycle
the pathways of various nutrient minerals or elements from the environment through organisms and back to the environment.
oil
a substance that is in a viscous liquid state (“oily”) at ambient temperatures or slightly warmer, and is both hydrophobic (immiscible with water) and lipophilic (miscible with other oils, literally). petroleum.
oil shales
sedimentary “oily rocks” that contain a mixture of hydrocarbons known as kerogen; oil shales must be crushed, heated, and refined to yield oil.
old-growth forest
a type of forest that has attained great age and so exhibits unique biological features.
oligotrophic lake
a deep, clear lake that has minimal nutrients. lots of dissolved oxygen.
omnivore
an animal that eats a variety of plant and animal materials.
open sea
the ocean.
open-pit mining
a type of surface mining in which a giant hole is dug to extract iron, copper, stone, or gravel.
ore
rock that contains a large enough concentration of a particular mineral that it can be profitably mined and extracted.
organic compounds
any member of a large class of chemical compounds whose molecules contain carbon.
organic farming
a form of agriculture that relies on crop rotation, green manure, compost, biological pest control, and mechanical cultivation to maintain soil productivity and control pests, excluding or strictly limiting the use of synthetic fertilizers and synthetic pesticides, plant growth regulators, livestock feed additives, and genetically modified organisms.
organic fertilizer
manure and such.
organism
a living being.
output pollution control
i don’t know.
overfishing
occurs when fishing activities reduce fish stocks below an acceptable level.
overgrazing
the destruction of an area’s vegetation that occurs when too many animals graze on the vegetation, consuming so much that it does not recover.
overnutrition
a condition caused by eating food in excess of that required to maintain a healthy body.
oxygen-demanding wastes
(BOD)
ozone
a blue gas, O3, with a distinctive odor.
ozone depletion
a slow, steady decline of about 4 percent per decade in the total volume of ozone in Earth’s stratosphere (ozone layer) since the late 1970s, and a much larger, but seasonal, decrease in stratospheric ozone over Earth’s polar regions during the same period.
ozone layer
a layer in Earth’s atmosphere which contains relatively high concentrations of ozone (O3).
PANs
i don’t know.
paradigm shifts
describe a change in basic assumptions within the ruling theory of science.
particulates
tiny particles of solid or liquid suspended in a gas or liquid.
parts per billion (ppb)
the number of molecules of a particular substance found in one billion molecules.
parts per million (ppm)
number of molecules out of one million molecules.
parts per trillion (ppt)
number of molecules per trillion molecules.
pasture
land with low-growing vegetation cover used for grazing of livestock as part of a farm, or in ranching or other unenclosed pastoral systems.
per capita ecological footprint
a measure of human demand on the Earth’s ecosystems.
per capita GDP
gross domestic product per person
percolation
the movement and filtering of fluids through porous materials.
permafrost
permanently frozen subsoil characteristic of frigid areas such as the tundra.
permeability
a measure of the ability of a material (typically, a rock or unconsolidated material) to transmit fluids.
perpetual resource
constant. solar energy ex.
persistence
a characteristic of certain chemicals that are extremely stable and may take many years to be broken down into simpler forms by natural processes.
persistent pollutant
pollutants that take extended time to decompose.
pest
any organism that interferes in some way with human welfare.
pesticide
any toxic chemical used to kill pests.
petrochemicals
chemicals, obtained from crude oil, that are used in the production of such diverse products as fertilizers, plastics, paints, pesticides, medicines, and synthetic fibers.
petroleum
a thick, yellow to black, flammable liquid hydrocarbon mixture found in earth’s crust.
pH
a number from 0 to 14 that indicates the degree of acidity or basicity of a substance.
phosphorus cycle
the worldwide circulation of phosphorus from the abiotic environment.
photochemical smog
a brownish orange haze formed by complex chemical reactions involving sunlight, nitrogen oxides, and hydrocarbons.
photosynthesis
the biological process that captures light energy and transforms it into the chemical energy of organic molecules, which are manufactured from carbon dioxide and water.
phytoplankton
microscopic floating algae that are the base of most aquatic food chains.
planetary management worldview
management of the planet.
plankton
small or microscopic aquatic organisms that are relatively feeble swimmers and thus, for the most part, are carried about by currents and waves.
plantation agriculture
plantation based agriculture.
point source
a single identifiable localized source of something.
pollutant
a toxic substance that can harm an organism or habitat.
pollution
any undesirable alteration of air, water, or soil that harms the health, survival, or activities of humans and other living organisms.
pollution cleanup
dissinfecting a polluted area.
pollution prevention
measures taken to prevent pollution from occuring.
polyculture
a type of intercropping in which several kinds of plants that mature at different times are planted together.
polyvarietal cultivation
cultivation of many varieties.
population
a group of organism of the same species that live in the same gerographical area.
population change
any change in the dynamics or form of the population.
population density
the number of individuals of a species per unit of area or volume at a given time.
population dispersion
the relative dispersion of a population.
population distribution
the distribution of members of a population.
population dynamics
the intricate dynamics of a population as a whole.
population size
the size of a population.
porosity
measure of the void spaces in a material, and is measured as a fraction, between 0–1, or as a percentage between 0–100%.
positive feedback loop
the system responds to perturbation in the same direction as the perturbation.
potential energy
stored energy that is the result of the relative position of matter instead of its motion.
poverty
a condition in which people are unable to meet their basic needs for adequate food, clothing, or shelter.
prairies
a region of flat, gently sloping, or hilly land covered chiefly by tall grasses and not many trees.
precipitation
any product of the condensation of atmospheric water vapour that is deposited on the Earth’s surface.
primary consumer
an organism that consumes producers.
primary pollutant
A pollutant that enters the air directly from a source.
primary productivity
the production of organic compounds from atmospheric or aquatic carbon dioxide, principally through the process of photosynthesis, with chemosynthesis being much less important.
primary sewage treatment
treating wastewater by removing suspended and floating particles by mechanical processes.
producer
an organism that manufactures complex organic molecules from simple inorganic substances.
pure free-market economic system
i don’t know
pyramid of energy flow
an ecological pyramid that shows the energy flow through each trophic level.
quagga mussel
a subspecies of freshwater mussel, an aquatic bivalve mollusk.
radiation
the emission of fast-moving particles or rays of energy from nuclei of radioactive atoms.
radioactive decay
the process in which a radioactive element emits radiation and, as a result, its nucleus changes into the nucleus of a different element.
radioactivity
the condition of being radioactive.
radioisotope
an unstable isotope that spontaneously emits radiation.
radon (Rn)
a colorless, tasteless, radioactive gas produced during the radioactive decay of uranium in earth’s crust.
rain shadow effect
an area of the downwind side of a mountain range with very little precipitation.
range
the are of earth in which a particular species occurs.
range of tolerance
Every population thrives in an optimal range of abitoic factors.
rangeland
land that is not intensively managed and is used for grazing livestock.
rare species
a species that occurs rarely in the wild.
realized niche
the life style that an organism actually pursues, including the resources that it actually is.
recharge area
an area where an aquifer is recharged.
recombinant DNA
a form of DNA that does not exist naturally, which is created by combining DNA sequences that would not normally occur together.
reconciliation ecology
the science of accommodating wild species within human-modified or -occupied landscapes.
recycling
conservation of the resources in used items by converting them into new products.
reforestation
the replacing of forest land.
reliable runoff
timely water run off.
renewable resource
resources that are replaced by natural processes and can be used forever, provided they are no overexploited in the short term.
replacement-level fertility
the aver number of children a couple must produce in order to replace themselves. 2.1
reproduction
the reproduction of an organism.
reproductive isolation
the isolation of certain reproductive members.
reproductive potential
the potential reproductive capacity of an organism.
reserves
resources in excess to be used when needed.
resource
any part of the natural environment that are used to promote the welfare of people or other species.
resource productivity
the natural production of a resource.
respiration
the transport of oxygen from the outside air to the cells within tissues and the transport of carbon dioxide in the opposite direction.
restoration ecology
the field of science in which the principles of ecology are used to help return a degraded environment as close as possible to its former state.
reuse
conservation of the resources in used items by using over and over again.
riparian zones
the thin patch of vegetation along the bank of a stream or river that interfaces between terrestrial and aquatic habits.
r-selected species
a reproductive strategy in which a species typically has a small body size, rapid development, short life span, and devotes a large proportion of its metabolic energy to the production of offspring.
r-strategists
a reproductive strategy in which a species typically has a small body size, rapid development, short life span, and devotes a large proportion of its metabolic energy to the production of offspring.
rule of 70
inflation will double the price level in (70/rate of inflation) years.
runoff
the movement of freshwater from precipitation and snowmelt to rivers, lakes, wetlands, and ultimately, the ocean.
salinity
the concentration of dissolved salts in a body of water.
salinization
the gradual accumulation of salt in a soil, often as a result of improper irrigation methods.
saltwater intrusion
the movement of seawater into a freshwater aquifer location near the coast.
scavenger
a carnivorous feeding behaviour in which a predator consumes corpses or carrion that were not killed to be eaten by the predator or others of its species.
scientific law
a concise verbal or mathematical statement of a relation that is always under the same conditions.
second law of energy
can’t be created or destroyed?
second law of thermodynamics
when energy is converted from one form to another, some of it is degraded into a lower quality, less useful form.
secondary consumer
an organism that consumes a primary consumers.
secondary pollutant
pollution that does not come from a primary source.
secondary sewage treatment
treating wastewater biologically, by using microorganisms to decompose the suspended organic material.
second-growth forest
a forest or woodland area which has re-grown after a major disturbance such as fire, insect infestation, timber harvest or windthrow, until a long enough period has passed so that the effects of the disturbance are no longer evident.
selective cutting
a forest management technique in which mature trees are cut individually or in small clusters while the rest of the forest remains intact so that the forest can regenerate quickly.
septic tank
the key component of a septic system, is a small scale sewage treatment system common in areas with no connection to main sewage pipes provided by private corporations or local governments.
shale oil
an organic-rich fine-grained sedimentary rock.
sheet erosion
the uniform removal of soil in thin layers by the forces of raindrops and overland flow.
shelterbelt
a plantation usually made up of one or more rows of trees or shrubs planted in such a manner as to provide shelter from the wind and to protect soil from erosion.
shifting cultivation
a traditional form of subsistence agriculture in which short periods of cultivation are followed by longer periods of fallow, during which times the natural ecosystems may become reestablished.
slash-and-burn cultivation
a type of shifting cultivation in tropical forests in which a patch of vegetation is burned, leaving nutrient minerals in the ash.
sludge
the residual semi-solid material left from industrial, or wastewater treatment processes.
smart growth
an urban planning and transportation theory that concentrates growth in the center of a city to avoid urban sprawl; and advocates compact, transit-oriented, walkable, bicycle-friendly land use, including neighborhood schools, complete streets, mixed-use development with a range of housing choices.
smelting
process in which ore is melted at high temperatures to help separate impurities.
smog
air pollution caused by a variety of pollutants.
social capital
concept developed in sociology and also used in business, economics, organizational behaviour, political science, public health and natural resources management that refers to connections within and between social networks as well as connections among individuals.
soil
the uppermost layer of earths curst, which supports terrestrial plants, animals, and microorganisms.
soil conservation
a set of management strategies for prevention of soil being eroded from the earth’s surface or becoming chemically altered by overuse, salinization, acidification, or other chemical soil contamination.
soil erosion
the wearing away or removal of soil from the land; caused by wind and flowing water.
soil horizons
the horizontal layers into which many soils are organized.
soil permeability
the ability of water to flow through the soil.
soil porosity
the porosity of soil.
soil profile
a vertical section through the soil, from the surface to the parent material, that reveals the soil horizons.
soil structure
determined by how individual soil granules clump or bind together and aggregate, and therefore, the arrangement of soil pores between them.
soil texture
a soil property used to describe the relative proportion of different grain sizes of mineral particles in a soil.
solar capital
economic value of solar energy.
solar energy
energy from the sun.
spaceship-earth worldview
i don’t know.
specialist species
can only thrive in a narrow range of environmental conditions or has a limited diet.
speciation
the evolutionary process by which new biological species arise.
species
a group of similar organisms that are able to interbreed with one another but unable to interbreed with other sorts of organisms.
species diversity
an index that incorporates the number of species in an area and also their relative abundance.
spoils
earth and rock excavated or dredged
stewardship worldview
the idea that humans share responsibility for the sustainable care and management of our planet.
stratosphere
the layer of the atmosphere between the troposphere and the mesosphere. it has a thin ozone layer that protects life by filtering out much of the sun’s ultraviolet rays.
strip cropping
a type of contour plowing that produces alternating strips of different crops that are planted along the natural contours of the land.
strip cutting
cutting along countours.
strip mining
a type of surface mining in which a trench is dug to extract the minerals, then a new trench is dug parallel to the old one.
subsidence
the sinking or settling of land caused by aquifer depletion.
subsistence farming
traditional agricultural methods that are dependent on labor and a large amount of land to produce enough food to feed oneself and one’s family, with little left over to sell or reserve for hard times.
subsurface mining
the extraction of mineral and energy resources from deep underground deposits.
succulent plants
water-retaining plants adapted to arid climate or soil conditions.
sulfur cycle
the worldwide circulation of sulfur from the abiotic environment into organisms and back into the abiotic environment.
sulfur dioxide (SO2)
the chemical compound with the formula SO2. It is produced by volcanoes and in various industrial processes.
sulfuric acid (H2SO4)
a strong mineral acid. It is soluble in water at all concentrations.
surface mining
the extraction of mineral and energy resources near earth’s surface by first removing the soil, subsoil, and overlying rock strata.
surface runoff
the water flow which occurs when soil is infiltrated to full capacity and excess water, from rain, snowmelt, or other sources flows over the land.
surface water
fresh water found on earth’s surface in streams and rivers, lakes, ponds, reservoirs, and wetlands.
survivorship curve
the probability that a given individual in a population will survive to a particular age.
sustainability
the ability to meet humanity’s current needs without compromising the ability of future generations to meet their needs.
sustainable agriculture
agricultural methods that rely on beneficial biological processes and environmentally friendly chemicals rather than conventional agricultural techniques.
sustainable development
a pattern of resource use that aims to meet human needs while preserving the environment so that these needs can be met not only in the present, but also for future generations to come.
sustainable living
refers to a specific lifestyle that attempts to reduce an individual’s or society’s use of the Earth’s natural resources.
sustainable society
one that persists and thrives.
sustainable yield
the ecological yield that can be extracted without reducing the base of capital itself, i.e. the surplus required to maintain nature’s services at the same or increasing level over time.
synergistic interaction
i don’t know.
synergy
e term used to describe a situation where different entities cooperate advantageously for a final outcome. Simply defined, it means that the whole is greater than the sum of its parts.
synfuels
a liquid or gaseous fuel synthesized from coal or other naturally occurring sources and used in place of oil or natural gas.
synthetic natural gas
manufactured form of natural gas.
tailings
piles of loose rock produced when a mineral such as uranium is mined and processed.
tar sand
an underground sand deposit permeated with a thick, asphalt-like oil known as bitumen.
temperature inversion
a deviation from the normal temperature distribution in the atmosphere, resulting a layer of cold air temporarily trapped near the ground by a warmer, upper layer.
terracing
a soil conservation method that involves building dikes on hilly terrain to produce level, terraced areas for agricultural.
terrestrial
pertaining to the land.
tertiary consumers
a high-level consumer, which is usually the top predator in an ecosystem and/or food chain.
tertiary sewage treatment
advanced wastewater treatment methods that occur after primary and secondary treatments and include a variety of biological, chemical, and physical processes.
theory of evolution
change in the genetic material of a population of organisms from one generation to the next.
thermal inversion
inverted temperature.
threatened species
a species in which the population is low enough for it to be at risk of becoming endangered in the foreseeeable future throughout all or a significant portion of its range.
throughput
the average rate of successful message delivery over a communication channel.
throwaway society
a human society strongly influenced by consumerism.
total fertility rate
the average number of children born to a woman during her lifetime.
traditional intensive agriculture
an agricultural production system characterized by the high inputs of capital, labour, or heavy usage of technologies such as pesticides and chemical fertilizers relative to land area.
traditional subsistence agriculture
self-sufficient farming in which farmers grow only enough food to feed their family and pay taxes.
tragedy of the commons
an influential article written by Garrett Hardin and first published in the journal Science in 1968.[1] The article describes a dilemma in which multiple individuals acting independently in their own self-interest can ultimately destroy a shared limited resource even when it is clear that it is not in anyone’s long term interest for this to happen.
transgenic organisms
organism modified to contain a gene of another organism.
transpiration
the loss of water vapor from the aerial surfaces of plants.
tree farm
farms of trees.
tree plantation
a plantation of trees.
trophic level
each level in a food chain level.
troposphere
the atmosphere from earth’s surface to the stratosphere.
true cost
actual cost.
undernutrition
a condition caused when a person receives fewer calories in the diet than are needed.
undiscovered resources
resources currently undiscovered.
uneven-aged management
the application of a combination of management actions that maintains several age-classes and tree sizes within a timber stand.
upwelling
a rising ocean current that transports cooler, nutrient laden water to the surface.
urban area
an area with an increased density of human-created structures in comparison to the areas surrounding it.
urban growth
the rate at which a city’s population grows.
urban sprawl
the spreading of a city and its suburbs over rural land at the fringe of an urban area.
urbanization
the process in which people increasingly move from rural areas to densely populated cities.
volatile organic compounds
organic chemical compounds that have high enough vapor pressures under normal conditions to significantly vaporize and enter the atmosphere.
warm front
the leading edge of an advancing mass of warm air; it separates warm air from the colder air ahead.
water cycle
the continuous movement of water on, above, and below the surface of the Earth.
water pollution
any physical or chemical change in water that adversely affects the health of humans and other organisms.
water table
the uppermost level of an unconfined aquifer, below which the ground is saturated with water.
waterlogging
the saturation with water.
watershed
an extent of land where water from rain or snow melt drains downhill into a body of water, such as a river, lake, reservoir, estuary, wetland, sea or ocean.
weather
the general condition of the atmosphere at a particular time and place.
weathering
a biological, chemical, or physical process that helps form soil from rock.
wetland
lands that are transitional between aquatic and terrestrial ecosystems and are covered with water for at least part of the year.
wild species
a species that lives in the wild.
wilderness
any area that has not been greatly disturbed by human activities and that humans may visit but do not permanently inhabit.
wildlife
animals living in the wilderness.
wildlife resources
naturally occuring wildlife resources.
windbreak
a plantation usually made up of one or more rows of trees or shrubs planted in such a manner as to provide shelter from the wind and to protect soil from erosion.
worldview
a particular attitude towards the environment.
xeriscaping
landscaping and gardening in ways that reduce or eliminate the need for supplemental irrigation.
zebra mussel
a species of small freshwater mussel, an aquatic bivalve mollusk.
zone of aeration
The subsurface sediment above the water table containing air and water. Also known as unsaturated zone; vadose zone; zone of suspended water.
zone of saturation
an area of soil or rock below the level of the water table where all the voids are filled with water
zoning
a device of land use regulation used by local governments in most developed countries.
zooplankton
the nonphotsynthetic organisms-tiny shrimp, larvae, and other drifting animals- that are part of the plankton.