Vegetation und ökologie eines Sphagnum-Moores in Südbrasilien

In the mountainous rainy climate of the Serra Geral in Southern Brazil, peat bogs have developed, characterized by a cover of Sphagnum pulchricoma over peat layers, about 2 meters thick. In one of these bogs, located in the National Park 'Aparados da Serra', 950 meters above sea-level, vegetation, stratigraphy and chemistry of the peats were examined. The physiognomy and floristic composition of the vegetation show clear relationships with the andine and subantarctic region. Grasses, often growing as tussocks, (Agrostis, Calamagrostis, Briza) on peats, rich of minerals (Table 1) alternate with types of vegetation, poor of species and characterized by wideleaved tall herbs and ferns (Table 2). On sites with up-welling groundwater a vegetation is growing which resembles that of the hollows in raised bogs of Central Europe. It consists of Mayaca sellowiana, Eryngium floribundum and Plantago gigantea (Table 3). The rosette plants Eryngium pandanifolium and Eriocaulon ligulatum as well as the low-growing tree fern Blechnum imperiale are striking in their appearance. The abundant growth of the species, the concentration of their roots in the upper 20 cm of the soil as well as the very close C/N relation and the high conductivity values of the amorphous and well decomposed peats (Table 5) allow the conclusion that there is a great micro-biological activity in spite of the permanently high ground water level, thereby mobilizing the high N-reserves of the upper peat layer. An accumulation of peat similar to that of the raised bogs, does not exist. Finally the close relationship between the bog genesis and the questions about vegetation history of this region (grass land-Araucaria-forest distribution in Southern Brazil) is discussed.