Submerged aquatic plants are found in this zone, but free-floating aquatic plants can also be found here. Approximately 6.6 feet is the depth to which aquatic plants can grow. As in other ecosystems, wetland and aquatic plant ecosystems possess their own unique ecology and successional patterns. Succession in ponds is marked by a sequence of plant communities that gradually replace each other until a pond matures and eventually disappears. In fact, the stages of succession in a body of water can be seen in the zonation of plants around it.
Succession begins with pioneer plants that colonize the body of water.
As these plants die, they release organic nutrients into the water thus enabling more plants to become established. Sediment gradually accumulates on the bottom of the body of water from the organic debris, which allows even more plants to become established. As the process continues, the body of water begins to diminish in circumference as the shore line begins to encroach on the middle of the pond. As this sediment builds up over time, the pond gradually changes into a swamp or marsh. The vegetation keeps encroaching to the center of the body of water, until it replaces the pond completely.