Ecological successions

In the oxbow lakes formed by channel cut-off along meandering rivers, flowing waters become stagnant and then become invaded by submerged aquatic vegetation (hydrophytes), which is itself dominated and then replaced by emergent vegetation (helophytes). These helophyte communities, such as reed beds, will in turn be invaded by marshland shrubs, which themselves may be replaced by hygrophilic forest communities. Likewise, herbaceous plants will become established on a newly deposited sand bar, followed by shrub thickets, which will tend to eliminate them, and these will in turn be replaced by larger trees. Of course, these changes in vegetation are accompanied by changes in the conditions of the habitat (e.g. nature of the soil, water depth) and animal populations. This is a very general phenomenon known as ecological succession.