hydrosere

hydrosere The sequence of plant communities (see sere) occurring during the change from shallow open water to forest or bog. The process commences with accumulations of silt, enabling initial colonization by submerged or floating plants, such as water lilies and pondweeds, depending on the rate of flow and nutrient status of the water. As silting increases and organic debris is deposited, reeds, sedges, and similar plants begin to appear, forming a swamp. Organic matter builds up as peat, and conditions progressively become drier, creating a stage called a fen, dominated by herbaceous species, and then a carr, in which shrubs and small trees predominate. Eventually, the substrate is sufficiently stable to support the larger trees of mature forest species. In conditions of high rainfall or low evaporation a different hydrosere may occur. The rate of peat formation may be sufficiently high to create a bog, i.e. a permanently waterlogged raised site that receives all its water and nutrient inputs from rainfall or other precipitation.