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BIO121-ch4
Term | Definition |
---|---|
biomass | living matter |
gross primary productivity (GPP) | total amount of energy fixed by autotrophs over a given period of time |
respiration: (R) | release of energy from fuel molecules |
net primary productivity (NPP) | amount of energy available for storage after respiration, GPP-R=NPP |
aerobic respiration | releasing energy with use of oxygen |
anaerobic respiration | obtaining energy from fuel molecules without use of oxygen |
estuary | semi-enclosed coastal body of water composed of fresh and saline water |
trophic levels | various levels in ecosystem—producers and successive steps removed from the producers |
food chains | successive steps within an ecosystem illustrating the energy transfers between organisms as a result of consumption |
food webs | interlocking change, woven into complex associations |
detritus food webs | webs based on decomposing plant and animal material or animal waste products |
pyramid of energy | shows production, use, and transfer of energy from one tropic level to another |
10% rule | on average, 10% of available energy is actually transferred at each step |
pyramid of biomass | shows total amount of living material at each trophic level |
pyramid of numbers | shows relative abundance of organisms at each trophic level |
biogeochemical cycles | involve living organisms and geologic and chemical factors |
Hydrologic cycle | all processes that account for the circulation of water through bodies of water, air, and land |
gaseous cycle | circulation of a gas thru the environment, primarily in the atmosphere, as materials circulate from the air, thru the land and water, and back again |
nitrogen fixation | process by which certain kinds of bacteria, either free-living in the soil or living in nodules (swellings) on plant roots, convert nitrogen to ammonia |
sedimentary cycles | involve materials that move primarily from the land to the oceans and back to land again |
ecosystem services | functions or processes of a natural ecosystem that provide benefits to human societies |