Patterns and drivers of forest landscape change in the Apennines range, Italy

Human activities and natural processes over millennia have shaped the forest landscapes of European mountain ranges. In the Apennines, the second largest range in Italy, the post-World War II abandonment of traditional activities has led to forest expansion. Previous analyses of land use change related to forest landscape were performed for relatively small localities and used different sampling protocols. Consequently, a replicate landscape approach and a systematic sampling design were crucial for quantifying changes at the regional scale. We investigated land cover change and landscape configurational shifts comparing different slope exposures and altitudinal zones and discussed the main drivers affecting post-agricultural forest dynamics. We selected two paired study landscapes (North-East vs South-West) of 16 km(2) for each of 10 sites located along the entire range. We applied object-based classification to aerial photography from 1954 and 2012, resulting in 40 land cover maps. We assessed (i) overall landscape changes by computing land cover transitions, (ii) landscape patterns through key metrics, and (iii) reforestation dynamics through multivariate statistics and binomial generalized linear models (GLMs). Apennine landscape mosaics experienced structural simplification at lower elevation due to tree establishment in abandoned pastures, but a diffuse fragmentation of historical grasslands at higher elevation due to development of woody vegetation patches beyond the forest-grassland ecotone. Forest expansion occurred more rapidly at lower elevations, on steeper slopes, and closer to existing forests and cultivated areas. A replicate landscape approach proved useful for quantifying changes to forest cover and landscape structure along complex gradients of topography and land use history, following a diffuse agro-pastoral abandonment.