Chapter 17: Change in Communities Flashcards
- Increases in sea level
- Warmer temperatures
- Pollution
- Reduced light availability
- Fires
- Floods
- Wind/rain/snow storms
- Volcanic activity
Abiotic agents of change
- Competition
- Mutualism/symbiosis
- Predation/herbivory
- Foundation species
- Keystone species
- Disease/parasitism
- Digging/burrowing
- Trampling
Biotic agents of change
Ecosystem engineers are an example
Interaction between biotic and abiotic factors
Event that directly injures or kills individuals to give opportunity to others
Disturbance
A factor that reduces growth of an important physiological process reducing growth reproduction or survival of some individuals
Stress
Agents vary in…
Intensity, frequency, and extent
The process of change in species composition over time as a result of agents of change
Succession (ex. open canopy to closed forest)
Pioneer species, intermediate species, climax species
Primary succession
Cycle restarting after primary succession
Secondary succession
Sand deposition builds up and succession is seen in levels - farther from the beach is farther along community
Cowles - space for time substitution
A community is a superorganism - growth toward a stable end point maintained indefinitely
Clements
A community is a collection of individuals - Individualistic view of succession
Gleason
Animals influence direction of succession
Elton
At each stage, species change the conditions to favour the next stage
Facilitation model
Changes are neutral to later stages, later succession occurs due to species tolerating the environment the way it is
Tolerance model
