An integrated model-data fusion framework to map the vulnerability of forest ecosystems to climate change in Greece

By shifting the structure and function of forest ecosystems, global change threatens their ability to provide key ecosystem services for human well-being. Lowland and mountainous Mediterranean forests are experiencing climate-related pressures that lead to changes in tree mortality, fire regime and their primary productivity. Understanding and mapping Mediterranean forest vulnerability to climate change is thus important for designing efficient adaptive management policies at the regional and country-level scale. In this project we developed an integrated framework that accounts for four (4) key components of forest vulnerability, i.e. drought mortality, wildfire frequency change, habitat suitability shrinkage and primary productivity shift. To do so, we combine dendro-ecological tree-ring data, fire risk and species distribution modelling, as well as regionally parameterized process-based simulations of forest gross and net primary productivity under two climate change scenarios, for the ten most ecologically and economically important tree-taxa in Greece, including evergreen needleleaf (EN), deciduous broadleaf (DB) and evergreen broadleaf (EB) representative species. In terms of drought triggered mortality, a relatively higher vulnerability of EN species (compared to DB and EB species), particularly at lower elevation emerged from the analysis of tree-ring data. Wildfire vulnerability was projected to be higher at lowland forests. Vulnerability related to habitat suitability changes was greater for mountainous DB and EN species. Simulated changes in primary productivity suggest a higher vulnerability at the lower elevation limits of species distribution. By combining the different vulnerability components, we provide species-specific vulnerability maps at a spatial resolution of ca 9 km, suitable for designing forest mitigation policies under different climate change scenarios.