Unveiling the future of relict Mediterranean mountain peatlands by integrating the potential response of ecological indicators with environmental suitability assessments

Mediterranean mountain peatlands are unique ecosystems because of their distinct hydrology and environmental conditions, as well as being home to a vast array of rare and endemic species. Due to anthropogenic activities and ongoing climate change, mountain peatlands are one of the most endangered ecosystems in Mediterranean areas. Climate scenarios for the western Mediterranean area estimate a sharp decrease in annual precipitation and an upsurge in temperature, which may disrupt the structure and functioning of ground-water-dependent ecosystems. To predict how the environmental suitability of Mediterranean mountain peatlands would be impacted by climate-induced changes, a microscale climatic model was used to downscale 2 m hourly air temperature to a high spatial resolution of 100 m in protected area of North Portugal. The environmental suitability was assessed based on bioclimatic indices associated with mountain peatland indicator species. Climate change projections envisage a decline in the environmental suitability of Mediterranean mountain peatlands and their indicator species, which could compromise this relict ecosystem probability of occurrence. Specifically, environmental suitability was considered highly sensitive to increases in temperature, namely when coupled with decreases in precipitation, resulting in significant reshaping of potential evaporation, evapotranspiration, and soil water content of the areas where peatlands actually occur. Also, the importance of microclimatic information for detecting change in ecosystems that are more vulnerable to climate change and in defining the best management options and conservation priorities is highlighted. Considering their vital role in the conservation of biodiversity and provider of ecosystem services, actions to mitigate and restore Mediterranean mountain peatlands are urgent.