1. Community Ecology Essential Standard
Bio.2.1 Analyze the interdependence of living organisms within their environments.

2. Symbiosis Symbiosis – close interactions among species
Predation, parasitism, competition, mutualism, and commensalism

3. Predation Predation - predator kills and consumes prey
Predator’s survival relies on ability to capture food
Prey’s survival relies on ability to avoid capture
Mimicry – harmless species resembles a harmful one
Camouflage – organisms blend into environment

4. Parasitism
Parasitism – one individual benefits and the other is harmed but not killed
Ex. Tick and dog; tapeworm and intestine

5. Competition
Competition – different species compete for same resources (niche overlap)
Competitive exclusion – one species is eliminated from community for same limited resource

6. Mutualism Mutualism – both species benefit from relationship
Ex. Pollinator and flower; crocodile and crocodile bird

7. Commensalism
Commensalism – relationship where one species benefits and the other is not affected

8. Properties of Communities
Species Richness – number of species the community contains
Species Diversity – number of species in relations to abundance of each species
Community Stability – resistance to change
Species richness improves community's stability
Figure: When the sea star was removed from an area where the sea stars had preyed on the mussels, the mussels crowded out many other competing species in the area. Predation by the sea star on the mussel promoted diversity by controlling the superior competitor – the mussel. (Species Stability)

9. Ecological Succession
Ecological Succession – gradual, sequential regrowth of species in an area
Primary succession – development of community where there was no previous life
Secondary succession – replacement of species that follows a natural disaster or human activity