2.6.5-.7 Succession

1. 2.6.5-.7 Succession

2. Succession is usually described as the orderly succession of communities to a climax community (biome) over time or as a sequence of communities (a sere) with each transitory community as a seral stage.

3. There are two main types of succession: • 1. Primary succession which begins with bare rock exposed by geologic activity • eg. sere: rock -> lichen -> moss -> grass -> shrub -> trees -> maple-beech -hemlock forest • 2. Secondary succession which begins on soil from which a previous community has been removed (by fire, agriculture, etc.)

4. Secondary succession can proceed much faster because the soil has already been prepared by the previous community

5. Differences between pioneer and climax communities

6. One thing that limits the carrying capacity, during succession for many organisms, is that the presence of these organisms (themselves) essentially alters the environment (eg. shade, pH, moisture, temperature, chemical composition) sufficiently so that it is no longer suitable for their own offspring to continue.

7. That is, the populations change the environment so drastically, both biotically and abiotically that it is now more suitable for other populations and less suitable for itself. This leads to the succession of one sere after another until a climax is reached and the changes in the environment are now not so drastic as to produce any further major changes.

8. Primary Succession

9. Succession in South Florida

10. the succession of a pond ecosystem to a meadow over 250 years.

11. The following charts summarize the major trends as the ecosystem undergoes succession.

12. Productivity

13. Mineral and Nutrient cycles