All Flashcards
What are the steps of primary succession?
- 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).
Outline the process of secondary succession.
- Disturbance occurs (e.g., fire). 2. Pioneer species (grasses/weeds) colonize. 3. Other plants establish. 4. Faster progression to climax community.
How do lichens contribute to soil formation?
Lichens use weathering and erosion to break down rock, creating soil.
What are the general steps of primary succession?
- Rock broken down by pioneer species. 2. Soil forms. 3. Grasses take root. 4. Shrubs and trees compete. 5. Hardwood trees form a forest.
What are the general steps of secondary succession?
- Disturbance occurs. 2. Grasses and weeds colonize. 3. Shrubs and young trees grow. 4. Fast-growing trees develop. 5. Climax community forms.
Define ecological succession.
The process of change in the species structure of an ecological community over time.
What is a climax community?
The final, stable stage of ecological succession where the ecosystem has reached a balance.
Define primary succession.
Ecological succession that begins in essentially lifeless areas, where soil has not yet formed.
What are pioneer species?
The first organisms to colonize a barren environment in primary succession.
Define secondary succession.
Ecological succession that occurs on substrate that previously supported vegetation before a disturbance.
What is a keystone species?
A species that has a disproportionately large effect on its environment relative to its abundance.
Define indicator species.
A species whose presence, absence, or abundance reflects the health of an ecosystem.