1. Chapter 3 Communities and Biomes
Section 1
Communities

2. Limiting Factors
Any biotic or abiotic factor that restricts the existence, numbers, reproduction, or distribution of organisms.
Factors that limit one population directly may also have an indirect affect on other populations.

3. Tolerance
The ability of an organism to withstand fluctuations in biotic or abiotic environmental factors.

4. Succession
The orderly, natural changes and species replacements that take place in the communities of an ecosystem.
Occurs in stages.
Each stage has conditions suitable for some organisms but not for others.
Takes decades to centuries to occur.

5. Primary Succession
The colonization of barren land by communities of organisms.
The first species to colonize in barren areas are called pioneer species.
Pioneer species eventually die out.
After some time, the community reaches equilibrium.

6. Climax Community
A stable, mature community that undergoes little or no change.
May last for hundreds of years.

7. Secondary Succession
The sequence of changes that takes place after an existing community is severely disrupted in some way.
Because soil already exists, secondary succession may take less time than primary succession to reach a climax community.