The ecological significance of organochemical compounds in Sphagnum

carpets work as a sponge which holds water very well and creates a permanently wet soil. Their characteristic cell wall structure gives them a high cation exchange capacity which at the same time acidifies the environment and traps nutrients. The production of organochemical compounds such as phenolics and uronic acids contributes to the suppression of vascular plant growth, as well as litter decomposition. Sphagnum species form thick lawns in bog hollows and dense, compact stands in hummocks. They create a hostile environment for other plant growth forms, and only specialized, slow-growing phanerogams survive in these conditions (During & Van Tooren 1990; Van Breemen 1995). The success of the genus in this respect has been attributed to several properties. Their morphology and anatomy makes Sphagnum by animals is known to be almost totally absent in bogs (Clymo & Hayward 1982), and decomposition of peat moss litter is notably slow, even if the material is transferred to a more favourable environment (Coulson & Butterfield 1978; Johnson & Damman 1993). Sphagnum