Advertisement Upgrade to remove ads

AP environmental science


production of ammonia or ammonium compounds in the decomposition of organic matter by bacteria


(nitrogen cycle step 3) plant absorbs ammonium (NH3) and nitrate ions (NO3) through roots


accumulation of a substance in various tissues of a living organism


# and variety of organisms in an area (ecosystem) more of it leads to better adaptability and chances of survival


process where concentration of toxic substances increase in each successive length in food chain.


organism that nourishes oxidation of inorganic chemical compounds, instead of photosynthesis

climax community

stable, mature community that reaches equilibrium after having evolved through stages and adapted to its environment




formed from populations of different species occupying the same geographic area


nitrogen cycle step 4) specialized bacteria convert ammonia to NO3, NO2, AND N2 and releases back to atmosphere


organism that gets energy by consuming nonliving matter

ecological succession

transition in species composition of a biological community, usually by a disturbance in community.


where 2 ecosystems meet


smaller regions in ecosystems that share similar physical features

edge effect

there is a greater species diversity and biological density than in the center of the ecological community

energy pyramid

10% of energy is transferred from 1 level to the next, 90% given off as heat, respiration, digestion, etc.

food web

complex interrelated food chains

fundamental niche

no competition

gause's principle

no 2 species can occupy same niche at same time

Gross Primary Productivity

amount of sugar that plants produce in photosynthesis ------ amount of energy that plant needs for growth, repair, etc.

habitat fragmentation

size of an organism's natural habitat is reduced or human civilization occurs


dependent on other complex organisms for food

indigenous species

species that originates from the area it lives in

invasive species

an introduced, nonnative species

keystone species

a species whose presence contributes to ecosystem's diversity and whose extinction would destroy other life forms

Law of Conservation of Matter

matter cannot be created nor destroyed


pioneer organisms, settle uninhabitable area and decomposes rocks to turn to soil, later lose to immigrants


relationship where both species benefit

natural selection

survival of the fittest

Net Primary Productivity

amount of energy that plants pass on to the community


total sum of species' use of resources in environment


(nitrogen cycle step 2) bacteria in soil convert ammonium (NH4+) to nitrate or NO3.

nitrogen fixation

(nitrogen cycle step 1) conversion of atmospheric nitrogen into compounds (ammonium)


relationship where 1 is helped, and 1 is harmed


carbs are synthesized from CO2 and H2O using light as energy source

pioneer species

organisms in first stage of succession


group of organisms of same species and same area


1 species feeds off another

primary consumers

organisms that consume producers (plants and algae)

primary succession

ecological succession begins in a near lifeless area


organism that can convert radiant energy or chemical energy to carbs

realized niche

when a species settles for a smaller niche after battling against another species


where large quantity of resources sits for long time

residency time

the amount of time a resource spends in a reservoir or an exchange pool


where animals and plants breathe and give off CO2 from cellular metabolism

secondary consumers

organisms that consume primary consumers


organisms that are capable of interbreeding with 1 another but unable to with other species

symbiotic relationships

close, prolonged associations between 2 or more different organisms of different species that may, but not necessarily, benefit

tertiary consumers

organisms that consume secondary consumers or other tertiary consumers


releasing water vapor through stomata of plants or pores

trophic level

feeding levels on food chain

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again


Reload the page to try again!


Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording