Grazing capacity of littoral meadows and reedbeds at Lake Mikri Prespa

Contrary to the various range types in terrestrial ecosystems, the grazing capacity of wet meadows and reedbeds has not been studied extensively in our country. Its estimation constitutes an important parameter for the proper management of littoral meadows with grazing, especially in wetlands where grazing is used or can be used to the benefit of both livestock-farming and the conservation of threatened habitats and wildlife species. This issue is particularly important for the aquatic fauna of Lake Mikri Prespa, where the surfaces of wet meadows have considerably decreased because of the expansion of dense reedbeds at their expense. The present work includes results of an experiment that took place at the western lakeshore from 1997 to 2000. In the end of each season, samplings were conducted in paired plots (grazed / ungrazed above-ground or emergent biomass) in four vegetation zones that are influenced in different ways by the fluctuating lake water level. The grazing capacity and percent used by the buffaloes presented major differences between the seasons and the vegetation zones. In the lower zones, these two parameters were considerably influenced by the extent of the seasonal fluctuation of the water level. The mean annual grazing capacity of the littoral meadow types (including reedbeds) was calculated to 2.2 buffalo units per ha (BU/ha). In the framework of a subsequent experiment at another littoral site, the stocking density used was 4.5 BU/ha. This grazing pressure led to the creation of a wet meadow type on a reed-dominated surface, while the grazing pressure of 2.2 BU/ha is considered suitable for its maintenance.