Changes in the Community

No life in the BLAST zone: no community, no soil.

Primary Succession

• Development of a community that has not supported life before.

• Rocks, sand dunes, volcanic islands

• Formation of soil

Primary Succession

• Development of a community that has not supported life before.

• Rocks, sand dunes, volcanic islands

• Formation of soil

Secondary Succession

• Secondary succession is the rebuilding of an ecosystem after a disturbance that damages or takes out all or part of the existing community, BUT leaves the soil.

• Floods, tornados, fires

• Secondary succession, as with primary succession, tends to result in the transition of a community from the original pioneer species to climax community.

• Climax Community: is a stable group of plants and animals that is the end result of succession.

• The rate of secondary succession is much faster than primary succession.

Succession in Water

Look familiar?? Which line represents primary succession? Secondary?

Limiting Factors for PopulationGrowth

• Density Dependent Factors- factors such as predation, competition, availability of food. Depends on how many organisms there are in a certain area.

• Density Independent Factors- Factors such as natural disasters- do not depend on how many organisms there are in an area.

• All biological populations experience exponential growth (see graph below), NOT linear growth.