Community Ecology and Species Richness Patterns

Community

Assemblage of populations in the same location.

Community ecology

Study of species interactions forming functional communities.

Species richness

Number of species in a community.

Latitudinal gradient

Species richness increases from polar to tropical regions.

Topographical variation

Mountainous areas increase habitat diversity and richness.

Peninsular effect

Species richness decreases with distance from land.

Intermediate disturbance

Moderate disturbances enhance species richness.

Time hypothesis

Communities gain species diversity over time.

Area hypothesis

Larger areas support more species and habitats.

Productivity hypothesis

Higher plant production leads to greater species richness.

Intermediate-disturbance hypothesis

Optimal species richness at intermediate disturbance levels.

Primary succession

Community development on newly exposed sites.

Secondary succession

Recovery on sites with existing biological legacy.

Climax community

Final stable community after succession.

Facilitation

Early species modify environment for later species.

Inhibition

Early colonists hinder establishment of later species.

Tolerance

Species establish without altering conditions for others.

Species-area effect

Relationship between area size and species diversity.

Evapotranspiration rate

Rate predicting tree species richness in ecosystems.

Disturbance types

Includes droughts, fires, floods, and hurricanes.

Egler's work

Study on floral succession and species tolerance.

Marine intertidal zone

Area where early colonists dominate space.

Clements' theory

Succession has a distinct endpoint in climax community.

Species interactions

Relationships affecting community structure and dynamics.