UAV-based habitat condition assessment of Prime Hoverfly Areas (PHAs) boosts their conservation

Summary

Hoverflies, the second most important pollinator group, essential for terrestrial ecosystems sustainability, are severely threatened by habitat degradation - the key driver of their decline. We examined the impact of variable microhabitat characteristics on hoverfly species richness within the identified Prime Hoverfly Area (PHA), on Mt. Stara Planina, Serbia. Potential vs recent species richness of hoverflies was studied, and an unmanned aerial vehicle (UAV) was used to map three different study sites. Detailed UAV-based habitat classification, the Map of the Natural Vegetation of Europe (EPNV), Geographical Information Systems (GIS) and Machine Learning (ML) were applied to quantify different microhabitat conditions. The results revealed that the highest degradation in habitat condition occurred due to a high anthropogenic pressure which led to hoverfly species richness decline. The established framework is applicable for other species or groups of species which are highly dependent on microhabitat conditions and their habitat conservation planning and management.