Virtual fences for conservation management in semi-natural grasslands: A case study from northern Europe

Semi-natural grasslands have great cultural and biodiversity value, but are threatened by land use change and abandonment. Grazing is essential to successful management of semi-natural grasslands, but its implementation for targeted nature conservation requires temporally and spatially varied management intensity. Virtual fence technology, where grazing animals wear GPS-tracked collars and are controlled by invisible digital boundaries, represents a potentially valuable tool for nature conservation management of these environments. This case study explores how virtual fences can be used for ecologically-tailored management of semi-natural grasslands. By combining GPS-based movement data from cattle with drone-based NDVI analyses, and field inventories of flowering plants and pollinators, the relationships between grazing patterns, vegetation, and conservation goals were analysed. The results show that virtual fences can regulate grazing pressure and create variation in vegetation structure and flower abundance in the short term. We found no clear link between pollinators and grazed and temporarily ungrazed areas with lower and higher flower abundance respectively, possibly due to high variation in pollinator numbers between consecutive survey days, and the mobility of flying insects across the virtual fence line. The combination of GPS data on livestock residence patterns and drone technology on changes in vegetation over this time period provides important information about interactions between the animals and the vegetation. The study demonstrates that virtual fencing has potential value for precision-oriented conservation and adaptive grazing planning.