Key Concepts in Ecosystem Dynamics and Interactions

TROPHIC LEVEL

hierarchical levels in an ecosystem

FOOD CHAIN

links species by their feeding relationships; 1 way flow of energy

FOOD WEB

network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem

10% RULE

Only 10% of the total energy produced at each trophic level is available to the next level. The amount of energy passed on reduces as you go up.

PRODUCER/AUTOTROPH

an organism that can make its own food

CONSUMER/HETEROTROPH

an organism that acquires energy by feeding on other organisms

DETRITIVORE

organism that feeds on plant and animal remains and other dead matter

DECOMPOSER

an organism that breaks down wastes and dead organisms

LIMITING FACTOR

factors that have great effects on limiting population growth

SYMBIOSIS

A close relationship between two species that benefits at least one of the species.

MUTUALISM

relationship between two species in which both species benefit

PARASITISM

relationship between two organisms where one benefits and the other is harmed

COMMENSALISM

A relationship between two organisms in which one organism benefits and the other is unaffected

FITNESS

an organism's ability to pass its genetic material to its offspring

NICHE

an organism's particular role in an ecosystem

CARRYING CAPACITY

largest number of individuals that an environment can support

BIODIVERSITY

the variety of living things in an ecosystem

BIOTIC

factors that are living

ABIOTIC

factors that are non-living

ECOSYSTEM

all the communities in an area and the physical (abiotic) environment

COMPETITION

the struggle between organisms to survive in a habitat with limited resources

POPULATION DENSITY

number of individuals living in a defined space

ADAPTATION

An inherited trait that helps an organism to better survive and reproduce

WATER CYCLE

how water evaporates from the surface of the earth, rises into the atmosphere, cools and condenses into rain or snow in clouds, and falls again to the surface as precipitation

CARBON CYCLE

transfer of carbon from the atmosphere to living organisms, and return back to the atmosphere through respiration, decay of organisms and burning of fossil fuels

NITROGEN CYCLE

transfer of nitrogen from the atmosphere to the soil, to living organisms, and back to the atmosphere