Ecosystems  Individuals and populations do no live along in nature but in association with at least a few, and usually a great many, ordered, machine-like organizations which use energy and raw materials in their operation.  This community of plants and animals, together with the environment that controls it, is called an ecosystem

Communities  Plants and animals that live together and make up the biological part of an ecosystem

Habitat & Niche The specific kind of environment occupied by the individuals of a species

Cycles 

Biotic Succession Changes in composition of vegetation at a given location through time

Food Chain  The series of organisms through which food energy moves before it is completely expended   

Food Web  A complex set of interlocking food chains

Biomass  Weight of living organisms in an ecosystem

Carrying Capacity

Limiting Factors

Natural Phenomena