| A | B |
|---|
| actual evapotranspiration | amount of water annually transpired by plants and evaporated from a landscape |
| biogeochemical cycle | nutrient circuits which involve both biotic and abiotic components of ecosystems |
| biological magnification | retained substances become more concentrated with each link in the food chain |
| critical load | amount of added nutrient usually nitrogen or phosphorus that can be absorbed by plants without damaging ecosystem integrity |
| decomposer | saprotrophic fungi and bacteria that absorb nutrients from nonliving organic material |
| detritivore | consumer that derives its energy from nonliving organic material |
| detritus | Dead organic matter |
| ecosystem | organisms in a given area as well as the abiotic factors with which they interact |
| eutrophication | nutrients |
| greenhouse effect | warming of planet Earth due to the atmospheric accumulation of carbon dioxide |
| green-world hypothesis | terrestrial herbivores consume relatively little plant biomass because they are held in check by a variety of factors including predators parasites and disease |
| gross primary production (GPP) | total primary production of an ecosystem |
| limiting nutrient | element that must be added for production to increase in a particular area |
| net primary production (NPP) | gross primary production of an ecosystem minus the energy used by the producers for respiration |
| primary consumer | organism in the trophic level of an ecosystem that eats plants or algae |
| primary producer | autotroph usually a photosynthetic organism |
| primary production | amount of light energy converted to chemical energy (organic compounds) by autotrophs in an ecosystem during a given time period |
| production efficiency | fraction of food energy that is not used for respiration |
| secondary consumer | member of the trophic level of an ecosystem consisting of carnivores that eat herbivores |
| secondary production | amount of chemical energy in consumers’ food that is converted to their own new biomass during a given time period |
| tertiary consumer | member of the trophic level of an ecosystem consisting of carnivores that eat mainly other carnivores |
| trophic efficiency | percentage of production transferred from one trophic level to the next |
| turnover time | time required to replace the standing crop of a population or group of populations |
