Unit 1 Vocabulary Part 2

nitrogen fixation

the assimilation of atmospheric nitrogen by soil bacteria and its release for plant use on the death of the bacteria

nitrification

the chemical process in which a nitro group is added to an organic compound

assimilation

the process by which plants and animals incorporate the NO3- and ammonia formed through nitrogen fixation and nitrification

ammonification

impregnation with ammonia or a compound of ammonia

denitrification

nitrate is reduced and ultimately produces molecular nitrogen

primary succession

happens when a new patch of land is created or exposed for the first time; organisms must start over

secondary succession

a patch of land is clear but there are still nutrients present

bottleneck effect

a species suddenly loses population

ecotone

a transition area between two biological communities, where two communities meet and integrate

competitive exclusion principle

two species with identical niches cannot coexist indefinitely

keystone species

a species on which other species in an ecosystem largely depend

aerobic

an environment where oxygen is present

anaerobic

not aerobic - no oxygen available