Abstract ID: 3.12213 | Accepted as Talk | Talk/Oral | TBA | TBA

Natural reforestation through secondary succession is one of the dominant ecological processes in mountain areas of developed countries. Given its complexity and variability, a harmonized approach for data collection and landscape-scale analysis is needed. Within the GeoLUCA project, we collected 114 case studies from the European Alps (50,000 km2) across six countries (Austria, France, Germany, Italy, Slovenia, Switzerland) spanning from the first half of the 19th century to 2022. We selected the European Alps as representative of the heterogeneous global change effects on forests due to the availability of LULCC data since the 19th century. We harmonized the LULCC data derived from historical cadasters (1800s), aerial photos (1950s-1980s-2020s), and satellite imagery (2000s-2020s) to obtain binary forest/non-forest gridded maps at a 10-m spatial resolution. Our aim was to identify the most important socio-ecological drivers of reforestation and discuss implications for planners and managers. We adopted change detection analyses, landscape metrics, and multivariate statistical models to understand landscape dynamics and quantify the role of drivers. Natural reforestation after abandonment in the European Alps was observed in all case studies, but with high local-scale heterogeneity. Climate and land-use abandonment were the dominant drivers of reforestation patterns. Reforestation rate was greatest on south-facing slopes of dry landscapes within remote and sparsely populated municipalities. The GeoLUCA geodatabase proved to be fundamental to capture the nonlinearity of past land-use/cover change over an area dominated by strong topographic gradients and extreme heterogeneity in socio-economic spatial patterns. We plan to adopt such a collection as a starting point for several ecological studies in the mountain range, such as treeline dynamics, species distribution, and ecosystem service characterization.