The process of change in the species structure of an ecological community over time.

The final, stable stage of ecological succession where the ecosystem has reached a balance.

Ecological succession that begins in essentially lifeless areas, where soil has not yet formed.

The first organisms to colonize a barren environment in primary succession.

Ecological succession that occurs on substrate that previously supported vegetation before a disturbance.

A species that has a disproportionately large effect on its environment relative to its abundance.

A species whose presence, absence, or abundance reflects the health of an ecosystem.

The process of ecosystem change over time.

The final, stable stage of ecological succession.

The first organisms to colonize a barren environment in primary succession.

A species with a disproportionately large impact on its ecosystem relative to its abundance.

A species that reflects the health of its ecosystem.

Ecological succession starting from bare rock or no soil.

Ecological succession starting with existing soil after a disturbance.

The plants of a particular region or habitat.

The animals of a particular region or habitat.

Break down rock to form soil through weathering and erosion.

1. Rock broken down by pioneer species. 2. Soil forms. 3. Grasses and plants take root. 4. Shrubs and trees compete. 5. Hardwood trees form a forest (climax community).

1. Disturbance occurs (e.g., fire). 2. Pioneer species (grasses/weeds) colonize. 3. Other plants establish. 4. Faster progression to climax community.

Lichens use weathering and erosion to break down rock, creating soil.