| A | B |
|---|
| Niche | Describes an organism’s use of resources and functional role in a community |
| tolerance | an organism's ability to survive and reproduce under changing environmental conditions |
| Specialist | organisms with very restricted tolerance ranges |
| Generalists | organisms that are able to live in a wide array of habitats |
| Competition | Organisms compete when they seek the same limited resource….food, space, light, water |
| Intraspecific competition | competition among members of the same species |
| Interspecific competition | competition among organisms of two or more different species |
| Competitive exclusion | one species can entirely exclude another from using resources. |
| Resource partitioning | competing species partition, or divide, the resource they use in common by specializing in different ways |
| Character displacement | when resource partitioning leads to evolution of physical characteristics among the competing species that reflect their specialized role in the environment. |
| Predation | The process by which a predator hunts, kills, and consumes prey |
| coevolution | the process by which two species evolve in response to changes in each other |
| Parasitism | One organism (the parasite) relies on another (the host) for nourishment or for some other benefit |
| Herbivory | An animal feeding on a plant |
| Mutualism | a relationship in which two or more species benefit |
| Commensalism | a relationship in which one species benefits while the other is unaffected |
| Primary Producers (Autotrophs) | Capture energy from the sun or from chemicals and store it in the bonds of sugars, making it available to the rest of the community |
| chemosynthesis | Energy from chemicals is captured by some bacteria |
| photosynthesis | Energy from the sun is captured by plants, algae, or bacteria |
| Consumers (Heterotrophs) | Rely on other organisms for energy and nutrients |
| Herbivores | plant-eaters |
| Carnivores | meat-eaters |
| Omnivores | combination-eaters |
| Detritivores and decomposers | recycle nutrients within the ecosystem by breaking down nonliving organic matter |
| trophic level | An organism’s rank in a feeding hierarchy |
| biomass | the mass of living tissue a trophic level contains. |
| Food chain | Linear series of feeding relationships |
| Food web | Shows the overlapping and interconnected food chains present in a community |
| Keystone species | Species that have strong and/or wide-reaching effects on a community |
| succession | Severe disturbances can cause permanent changes to a community and initiate a predictable series of changes |
| Primary Succession | occurs when there are no traces of the original community remaining, including vegetation and soil |
| Pioneer species | Well adapted for colonization: spread quickly, spores or seeds that can travel long distances |
| Secondary Succession | Occurs when a disturbance dramatically alters a community but does not completely destroy it |
| Invasive species | Nonnative organisms that spread widely in a community |
