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

Although anthropogenic activities affect the ecological conditions of mountain lakes worldwide, 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 enabled conceptualization of hypothetical impacts of multiple indicators used to quantify ecosystem services. Results indicate that increasing temperatures influence almost all ecosystem service indicators, impacting negatively water availability in particular, but also exerting positive effects on recreation. Changes in water use have mostly negative impacts, specifically on indicators related to habitat and aesthetics. For indicators such as trophic state, water clarity, water availability, riparian vegetation complexity, and nitrate content, up to six pressures may interact. Overall, the 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, whereas 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 emphasize interdisciplinary assessments in bridging limnological parameters to ecosystem service indicators, to better connect the pressures of global change to human benefits derived from mountain lakes. This information is useful for mitigating or adapting to the impacts of change.