Ecosystems and Interactions

Producers, Consumers, and Decomposers

Biotic and Abiotic Factors in Ecosystems

Levels of Ecological Organization: Organism to Ecosystem

Limiting Factors and Carrying Capacity

Ecological Succession: Primary and Secondary

Community Interactions: Competition and Predation

Food Chains, Food Webs, and Trophic Levels

Symbiosis: Mutualism, Commensalism, and Parasitism