Influence of thinning intensity and frequency on the provision of ecosystem services in Mediterranean mountain pine forests under climate change scenarios

Thinnings are silvicultural operations that repetitively reduce tree density to improve the ecological, economic, and social benefits of the stands. Thus, the correct choice of the thinning regime can enhance stand structure and the provision of various ecosystem services throughout the rotation period. In this study, we use a modelling approach to evaluate stand dynamics and the provision of ecosystem services (mushroom production, wood for timber, carbon storage, blue water, and habitat for biodiversity) in Mediterranean mountain pine forests under different thinning regimes – defined by intensity and frequency – and under two different climate change scenarios. We implemented the thinning regimes using SORTIE-ND, an individual-based model that simulates forest dynamics, and then we integrated models developed for the study area to calculate the provision of services. We used as a case study a Pinus sylvestris and a Pinus nigra stand and we evaluated the effect of the thinning regime, in terms of intensity and frequency, the effect of climate change, and the effect of forest type over a rotation period. Our results show that overall, the production of mushrooms, timber, and carbon decreased with increasing intensity and shortening frequency, while the blue water increased under those conditions. The application of thinnings favoured the habitat for biodiversity by producing more large dead trees and faster. Large timber was better supported by a thinning regime with heavy intensity and shorter frequencies. We found synergies between the production of mushrooms, timber, and carbon, while blue water is in a trade-off relationship with these services. Biodiversity showed a weak relationship with the rest of studied services. Furthermore, our results have shown that climate change will lower the production of ecosystem services under the most severe climate predictions. Based on our results, we can conclude that our modelling approach is a useful and efficient tool for answering questions that would otherwise require long-term studies, and that it can provide useful information to guide management efforts to adapt forest management to the challenges of climate change.