Trade-offs between economic profitability, erosion risk mitigation and biodiversity in the management of uneven-aged Abies alba Mill. stands

Multi-objective forest planning methods were used to assess the trade-offs between three ecosystem services: timber production, erosion protection and biodiversity. The use of trade-off analysis helps to define proper weights for the management objectives and evaluate the feasibility of obtaining economic profit from timber while controlling the erosion risk and maintaining biodiversity of Abies alba Mill. Forests provide several ecosystem services (ES), many of which are in trade-off. The assessment of relationships between ES helps to optimize forest management. This study analyses the trade-offs between timber production, erosion protection and biodiversity in uneven-aged mountain forest of Abies alba Mill. Multi-functional forest management was optimized using a simulation-optimization software. Timber production was measured with present value, erosion risk was modelled as a function of stand structure, and biodiversity was dealt with by setting a minimum number of 10 large trees (dbh > 60cm) per hectare as a requirement. Optimizations were conducted for slopes of 10%, 45% and 80% and cutting cycles of 10, 30 and 50 years. Discount rate 2% was used in all optimizations. Trade-offs were evaluated with production possibility boundaries. We found relevant trade-offs between timber production and erosion protection, which depended on the slope steepness and the length of the cutting cycle. Trade-offs were marginal on 10% slope (50-year cycle) and large on 80% slope (10-year cycle). Biodiversity constraint reduced both economic profits and erosion protection values. In multifunctional mountain forest, defining proper weights for ecosystem services that are in trade-off is important for satisfying different management objectives in a sustainable way.