All Flashcards
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.
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.