A quantitative approach to the understanding of social-ecological systems: a case study from the Pyrenees

Mountains are social-ecological systems exposed to multiple climatic and socioeconomic drivers. The Pyrenees are a clear example of the concomitant challenges that these regions face, as they are exposed to stressors linked to depopulation, an economic shift towards tourism, and climate change. To understand how these multiple stressors affect the system's resources, it is useful to study them from a social-ecological system (SES) perspective. Focusing on a Pyrenean SES, we use piecewise structural equation modeling and network analysis to quantitatively describe the interactions between water resources, biodiversity, and the social and economic elements of the system. Our results show that the current economic focus and dependency on tourism severely impact water resources and biodiversity. Future climatic scenarios forecast a worsening of the pressures on the hydrological system and may threaten winter tourism. Actions to alleviate the pressures on water and biodiversity and to increase socioeconomic resilience are a priority. We argue that such actions will have to include both a diversification of the region's touristic offer and of the economy, coupled with a more sustainable use of water resources. Our findings highlight the importance of studying the interactions and causal relationships between SES elements. This can help gain a comprehensive understanding of how the SES functions and its sustainability challenges.