Synergies between biodiversity conservation and drinking water protection in an agriculture dominated landscape – Case study of the Lower Savinja Valley in Slovenia

Abstract

The growing world population and global market competition are putting pressure on high-yield food production, reducing the space available for low-intensity agricultural practices that support high biodiversity. In search of synergies between different environmental policy instruments, the potential of drinking water protection zones (WPZ) for high nature value (HNV) farmland conservation and connectivity in the Lower Savinja Valley in Slovenia was examined. In drinking water protection zones, restrictions of fertilizer and pesticide use are enforced, which have demonstrated beneficial effects on biodiversity. Overall, HNV farmland covered 25.8% of the area, of which 6% was protected in almost equal proportions by Natura 2000 sites and WPZ. Zonation prioritization assigned higher average scores to cells in WPZ compared to Natura sites and unprotected areas indicating high value of WPZ for HNV connectivity. The proportion of WPZ receiving the highest Zonation prioritization scores ranged from 23% to 70% depending on connectivity scale. Simulation of conversion of arable to HNV farmland on WPZ added 58.2 ha, and increased overall HNV farmland cover in the Lower Savinja Valley from 25.8% to 26.3%, further reinforcing the importance of WPZ for connectivity. Drinking water protection zones under different levels of protection cover approximately 20% of the territory of Slovenia. Given their large extent, we suggest that when planning for HNV farmland conservation and ecological networks within intensive agriculture dominated landscapes, WPZ should be evaluated for their potential and integrated into planning. Analysis focused on the spatial configuration of HNV farmland but lacked information on habitat quality, species presence and management practices in WPZ. Further studies of the effect of WPZ management restrictions on biodiversity are needed.