Ecology involves the interactions between the biotic and the abiotic components
of the environment that form ecosystems. Matter and energy flow through these
systems as populations maintain equilibrium, undergo growth, or experience
change due to succession.

Supporting Ideas:
1. Ecological stability is affected by abiotic and biotic factors. Populations can
survive within a limited range for each abiotic factor.
2. Water, carbon, oxygen, and nitrogen cycle through ecosystems in
biogeochemical cycles.
3. In an ecosystem, energy flows from producers through consumers to
decomposers. As energy is transferred from one trophic level to the next, some
energy is lost.
4. There are a number of ways in which species interact: symbiotic relationships
(parasitism, commensalism, and mutualism), competition, and predation.
5. Abiotic factors determine the distribution of organisms in large ecosystems called
biomes. The biosphere is composed of a number of terrestrial and aquatic
biomes.
6. Ecological succession involves an orderly change of physical conditions and
biotic communities in an ecosystem. The climax community represents the final
stage of an ecological succession.
7. Competition and predation, availability of resources, seasonal changes, natural
disasters, or human activity, are factors that may limit population growth and
size.