Term | Definition |
abiotic factor | an environmental factor that is not associated with the activities of living organisms |
ammonification | the formation of ammonia compounds in the soil by the action of bacteria on decaying matter |
biosphere | the part f the earth where life exists; includes all of the living organisms on earth |
biotic factor | an environmental factor that is associated with or results from the activities of living organisms |
biomass | any organic material that has been produced in an ecosystem |
biogeochemical cycle | the circulation of substances through living organisms from or to the environment |
community | a group of various species that live in the same habitat and interact with each other |
acclimation | an organisms change in response to a change in the organisms environment |
consumer | an organism that eats other organisms or organic matter instead of producing its own nutrients or obtaining nutrients from inorganic sources |
chemosynthesis | the production of carbohydrates through the use of energy from inorganic molecules instead of light |
carnivore | an organism that eats animals |
carbon cycle | the movement of carbon from the nonliving environment into living things and back |
dormancy | a state in which seeds spores bulbs and other reproductive organs stop growth and development and reduce the metabolism especially respiration |
detritivore | a consumer that feeds on dead organisms or on the parts or wastes of other organisms |
decomposer | an organism that feeds by breaking down organic matter from dead organisms; examples include bacteria and fungi |
denitrification | the liberation of nitrogen from nitrogen containing compounds by bacteria in the soil |
ecology | the study of the interactions between organisms and other living and nonliving components of their environment |
ecological model | a model that represents or describes the relationships between the components of an ecological system |
ecosystem | a community of organisms and their abiotic environment |
food chain | the pathway of energy transfer through various stages as a result of the feeding patterns of a series of organisms |
food web | a diagram that shows the feeding relationships among organisms in an ecosystem |
gross primary productivity | the rate at which organic matter is assimilated by plants and other producers during a period of time over a certain area |
ground water | the water that is beneath the earth's surface |
habitat | the place where an organism usually lives |
herbivore | an organism that only eats plants |
interdependence | the dependence of every organism on its connections with other living and nonliving parts of its envrionment |
migration | in general, any movement of individuals or populations from one location to another; specifically as periodic group movement that is characteristic of a given population or species |
niche | the unique position occupied by a species both in terms of its physical use of its habitat and its function within an ecological community |
net primary productivity | the rate at which biomass accumulates in an ecosystem |
nitrogen cycle | the process in which nitrogen circulates among the air, soil, water, plants and animals in an ecosystem |
nitrogen fixtation | the process by which gaseous nitrogen is converted into nitrates compounds that organisms can use to make amino acids and other nitrogen- containing organic molecules |
nitrogen fixing bacteria | a bacterium that converts atmospheric nitrogen into ammonia |
nitrification | the process by which nitrites and nitrates are produced by bacteria in the soil |
omnivore | an organism that eats a variety of other organisms including animals and plants |
population | a group of organisms of the same species that live in a specific geographical area and interbreed |
producer | an organism that can make organic molecules from inorganic molecules; a photosynthetic or chemosynthetic autotroph that serves as the basic food sources in an ecosystem |
phosphorus cycle | the cyclic movement of phophorus in different chemical forms from the environment to organisms and then back to the environment |
tolerance curve | a graph of the performance of an organism versus the value of an environmental variable |
trophic level | an organisms relative position in a sequence of energy transfers in a food chain or food pyramid, examples include producers and primary, secondary and tertiary consumers |
transpiration | the process by which plants release water vapor into the air through stomata; also the release of water vapor into the air by other organisms |
water cycle | the continuous movement of water between the atmosphere, the land, and the oceans |