The costs of providing tomorrow’s forest ecosystem services: A framework for assessing harvesting methods and management costs under future forest dynamics

Forest management across Europe is confronted with a broad range of uncertainties, including the ecological and economic implications of silvicultural adaptation strategies. Especially in regions with limited forest accessibility, silvicultural constraints, and challenging topographic conditions, the economically viable potential for multifunctional management of forest ecosystem services is determined by its costs. In Swiss mountain forests, for example, costs for timber harvesting and extraction regularly exceed timber revenues; nevertheless, forest management is considered essential to sustain the forests’ protective function against gravitational hazards. Especially under future forest dynamics, it remains unexplored to what extent timber production alone is sufficient to cover forest management costs. Thus, for long-term assessments of management costs across various biogeographic conditions, structured frameworks that integrate both dynamic forest modelling and operational considerations are required to assess potential economic barriers for future forest management.

To close this gap, we present a comprehensive framework to assess socio-economically best suitable timber harvesting methods (BEST) and corresponding harvesting costs in response to long-term forest dynamics. Across the Swiss National Forest Inventory (NFI), we integrated (i) dynamic simulations of alternative management strategies under climate change using the forest model MASSIMO, (ii) technical assessments of state-of-the-art harvesting methods, and (iii) timber harvesting productivity models allowing the estimation of associated harvesting costs.

Our results revealed considerable temporal shifts in BEST portfolios that were mediated by an interplay of varying topographic conditions, differences in forest accessibility, as well as current forest composition and corresponding forest trajectories – for example, with higher shares of air- and cable-based harvesting methods being assigned within the Alpine regions. Further, considerable shifts in harvesting costs in response to long-term forest dynamics were observed. For example, in the Jura, the proportion of managed NFI plots with harvesting costs of < 50 CHF m^-3 decreased from approx. 80 % (year 2023) to 50 % (year 2113) under a management strategy aiming for constant growing stocks. Over the simulation period, mean timber harvesting costs remained comparatively stable in the Swiss Prealps and Alps, whereas long-term increases were modelled for both the Jura and Plateau. Notably, harvesting costs under BEST were consistently lower than those estimated under the continuation of currently applied methods (i.e. as documented within the NFI), highlighting the potential for increased cost efficiency through shifts in harvesting methods.

We conclude that climate- and management-induced shifts in forest dynamics may affect the economically viable potential for forest ecosystem service provision. Especially in regions where management costs outweigh timber revenues, economic assessments and decision-support tools need to adopt a supply-cost perspective by accounting for shifts in harvesting methods and associated costs. Further, the development of strategies aiming for forests’ adaptation to climate change needs to consider their long-term economic and technical implications to proactively identify real-world barriers to successful implementation.