Grazing intensity and ecosystem services in the alpine region

In the alpine summer-grazing area, grazing intensity is one of the most important management variables controlling vegetation and ecosystem services. In spite of this, grazing intensity is difficult to quantify on large, heterogeneous alpine pastures. For this reason, local grazing intensity on two alpine summer dairy farms in the canton of Obwalden and in the Lower Engadine, Switzerland, were quantified by means of GPS tracking. The two farms differed in terms of environmental conditions and grazing management. Local grazing intensity on both farms was strongly determined by natural conditions such as slope of the terrain, forage quality, and distance to sheds and water sources. An effect of grazing management on local grazing intensity was only detectable on the farm where strict rotational grazing is practised. On this farm, a negative correlation was also found between grazing intensity and plant species richness. By contrast, ecosystem services on the summer-grazing farm with large pasture plots and free-range grazing were largely determined by environmental conditions and pasture management. This shows that strict grazing management is necessary in order to control the provision of ecosystem services on summer-grazing pastures via grazing intensity.