Most photosynthesis takes place near the surface of aquatic systems. Provides the most stable aquatic environment. Absorbs and holds large quantities of solar heat and helps to stabilize the earth's atmosphere. Contains a relatively constant supply of nutrient materials and dissolved salts. Serves as a habitat for a large number of diverse organisms.
Ecosystems tend to change with time until a stable system is formed.
The type of ecosystem that is formed depends on the climatic limitations of a given geographical area. Each community modifies its environment, often making it more difficult for itself and, apparently, more favorable for the following community which infiltrates the first community over a period of years. The climax community of a region is always named by its dominant plant species. A climax community persists until a catastrophic change of a major biotic or abiotic nature alters or destroys it. After the original climax community has been destroyed, succession occurs once again leading to a climax community.