Towards sustainable management of forest residues in the southern Apennine Mediterranean mountain forests: a scenario-based approach

Key message: Managing forest residues according to the carbon content of the soil helps to minimize the ecological footprint of their removal. Context: In Mediterranean mountain ecosystems, unsustainable harvesting of wood residues might contribute to land degradation, carbon, and nutrient depletion in forest soils. Aims: This study aimed to assess the amount of forest biomass residues that should be left on-site to minimize the depletion of soil fertility. Methods: We estimated the availability of biomass residues in the public forest land of the Basilicata region of Southern Italy by collecting stand-scale inventory attributes from forest management plans. Subsequently, we quantified the amount of forest biomass residue released by implementing a scenario-based approach. Results: Approximately 5800 m3 year−1 of forest residues could be potentially available for bio-based industries at the regional scale within the next 10 years. Such residues mainly belong to broadleaved forest types, having a high variability in their soil organic stock (228.5–705.8 Mg C ha−1) and altitudinally spanning from 400 to 1500 m a.s.l. In these forests, the simulated scenarios displayed a wide range of average harvestable residues from 2.5 to 5.5 m3 ha−1, containing approximately 1.1 to 2.1 Mg ha−1 of organic carbon. Conclusion: Our study suggests that forest management plans are a useful source of information to estimate the available forest biomass residues consistently. In southern Mediterranean mountain forests, the management of forest residues according to soil carbon content helps to minimize the environmental impact and increase their sustainability