| A | B |
|---|
| Community | two or more populations of different species occupying the same geographical area |
| Community ecology | the study of how different species interact within communities |
| Competitive exclusion | species who utilize the same resources cannot coexist indefinitely; "one niche, one species" |
| Condensation | process of changing from a gas to a liquid |
| Consumer | organism that cannot create energy-rich molecules but obtains its food by eating other organisms |
| Deforestation | removal of trees from a forested area without adequate replanting |
| Demographic Transition | hypothesis that countries, as they become industrialized, have declines in death rates followed by declines in birth rates |
| Desertification | conversion of rangeland, rain-fed cropland to desert-like land, with a drop in agricultural productivity of 10% or more; caused by a combination of overgrazing, soil erosion, prolonged drought, and climate change |
| Dioxin | a synthetic, organic chemical of the chlorinated hydrocarbon class; one of the most toxic compounds known to humans, having many harmful effects, including induction of cancer and birth defects, even in extremely minute concentrations; has become a widespread environmental pollutant because of the use of certain herbicides that contain dioxin as a contaminant |
| Ecology | the study of how organisms interact with one another and with their environment |
| Ecological succession | a directional, cumulative change through time in the species that occupy a given area |
| Ecosystem | a system of interdependent organisms which share the same habitat |
| Energy pyramid | shows the amount of energy available at each feeding level in an ecosystem |
| Energy flow | 1) energy cannot be created or destroyed; it can only be changed from one form to another. 2) whenever energy is transformed, there is a loss of energy through the release of heat |
| Environment | biotic (other organisms) and abiotic (physical factors) |
| Evaporation | when liquid water changes into water vapor, which is a gas, and enters the atmosphere |
| Food chain | shows how each living thing gets its food |
| Food web | interrelated food chains in an ecological community |
| Gross primary productivity | the rate at which primary producers capture and store energy per unit time |
| Habitat | where a species normally lives |
