The Decomposition of Emergent Macrophytes in Fresh Water

Publisher Summary This chapter discusses the sources of emergent plant organic matter reaching the fresh water and the impact of various agents of decomposition on it. The distinctive environmental features of emergent macrophyte swamp are also discussed. Detritus, the resource of decomposition, can originate from any nonpredatory loss of organic matter from any trophic level. The primary resources are those that are derived directly from the plant. They include litter and the soluble matter, which may be lost from plants while they are alive. The secondary resources are provided indirectly, for example, by the defecation or death of animals feeding on the litter. Weight loss from the litter exhibits a high initial rate, which subsequently declines. Although it is difficult experimentally to separate the two processes, the initial rapid decomposition is a case of leaching, the abiotic loss of soluble components. The later phase depends predominantly on the activities of decomposer organisms and is generally assessed as a breakdown rate, the speed at which weight is lost from contained or tethered litter.