Datensatz

Zusammenfassung

Streamside wetlands cover large areas in the tropics because of high stream density, high discharge fluctuations, and, in the lowlands, a flat relief. In streams shaded by streamside forest, food webs depend on carbon input from the wetlands and the uplands because of low instream primary production. However, litter break down in tropical streams is slower than in temperate ones, because of low nutrient level and hard consistence of the litter. The aquatic shredder community is impoverished in species and in abundance. Litter break down in the wetlands and uplands by terrestrial organisms and the input of fine particulate and dissolved organic matter during spates and floods, but also the input of high valuable external food sources, e.g., terrestrial insects and fruit, seem to be more important for tropical streams than for temperate ones. Despite of a very small database on tropical stream organisms and dramatic taxonomic gaps, overall species diversity in tropical streams seem to be not higher than in temperate ones, however with differences within different plant and animal families. A greater biodiversity may occur in the streamside wetlands, probably related with the larger number of flood tolerant tree species. The importance of the River Continuum Concept and the Flood Pulse Concept for tropical streams and streamside wetlands is discussed. The role of an intact network of streamside wetlands for biodiversity in the landscape and the need for the protection of streamside wetlands is focussed.