Download Communities - Choteau Schools

Communities
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.
Tolerance
• The ability of an organism to withstand
fluctuations in biotic or abiotic
environmental factors.
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.
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.
Climax Community
• A stable, mature community that
undergoes little or no change.
• May last for hundreds of years.
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.