Wild Red Deer Benefit the Conservation of European Semi-Natural Open Habitats

Wild Red Deer Benefit the Conservation of European Semi-Natural Open Habitats

Traditional land use practices have shaped European landscapes for millennia. Agricultural intensification and declining popularity of pastoral farming in the past century have resulted in a tremendous loss of extensively used open landscapes and associated biodiversity. Today, conservation management needs to prevent secondary succession of many open habitats. Large or inaccessible target areas unsuitable for conventional conservation measures might benefit from grazing by wild herbivores, which do not require fencing nor regular welfare monitoring. In a military training area in Germany, we studied the quantitative and qualitative effects of wild red deer in two protected open habitat types (lowland hay meadows and European dry heaths) based on grazing exclusion experiments over three years. Using movable exclusion cages, we showed that the amount of biomass annually removed by red deer was similar to the forage removal in livestock-based conservation grazing systems. Mown grasslands were particularly attractive to red deer owing to enhanced productivity and forage quality, suggesting that red deer grazing activities can be influenced by mowing. In addition, we compared the vegetation development in grasslands and heathlands with and without red deer grazing using open and permanently fenced plots. Grassland plant diversity decreased in fenced plots. In both habitat types, different structural vegetation characteristics, e.g. increasing sward and litter height, indicated successional developments when red deer grazing was excluded. Our results substantiate that allowing red deer access to open landscapes could not only alleviate potential conflicts with forestry, but can also promote open vegetation structure and diversity, thus providing a valuable contribution to the conservation management of semi-natural habitats.