How do anthropogenic pressures affect the provision of ecosystem services of small mountain lakes?

Abstract

Anthropogenic activities affect ecological conditions of mountain lakes worldwide. However, the impacts on human wellbeing in terms of ecosystem services provided by lake ecosystems remain unclear. This study identified potential impacts of anthropogenic pressures on seven key ecosystem services of small mountain lakes. The Driver-Pressure-State-Impact-Response framework was applied to conceptualise hypothetical impacts of multiple indicators used to quantify ecosystem services. The results indicate that increasing temperatures influence almost all ecosystem service indicators, having in particular negative impacts on water availability, but also some positive effects on recreation and research. Changes in water use have mostly negative impacts, specifically on indicators related to habitat and aesthetic. For indicators such as trophic state, water clarity, water availability, riparian vegetation complexity, nitrate content up to six pressures may interact. Overall, greatest impacts can be expected on the ecosystem services habitat, water, aesthetic and existence. To support targeted management strategies, two contrasting groups of mountain lakes were distinguished, accounting for socio-ecological differences related to recreational and agricultural use. Lakes of low suitability for human use (i.e., high and/or remote) are mostly affected by large-scale drivers such as climate change, while lakes of high suitability for human use (i.e., low and/or easily accessible) are more often affected by pressures exerted by changes in local water use. These findings suggest that future research should set more efforts in interdisciplinary assessments, bridging limnological parameters to ecosystem service indicators, to improve the understanding of global change pressures on human benefits derived from mountain lakes. This information can be used to mitigate or adapt to adverse impacts of changing environmental conditions and to develop sustainable management strategies.