Uneven-aged management options to promote forest resilience for climate change adaptation: effects of group selection and harvesting intensity

International audience& Context Climate change is expected to increase forest vulnerability through disturbances such as windstorms and droughts. Forest managers are therefore investigating strat-egies to increase forest resistance and resilience, especially by promoting uneven-aged and mixed forests through group selection, and by reducing stand stocking and large trees proportion. However, there is little information on the long-term impacts of these two practices. & Aims The objectives of this study were (1) to develop an original silviculture algorithm designed for uneven-aged man-agement and (2) to use it to assess the effects of the above-mentioned management methods in long-term simulations. & Methods We simulated individual and group selection tech-niques in order to study the effects of group size, harvesting intensity and their interactions on wood production, stand heterogeneity, and regeneration in mountain spruce–fir for-ests. We used the spatially explicit individual-based forest model Samsara2 to simulate forest dynamics. & Results Our simulation results confirmed the positive ef-fect of group selection practices on structure diversity and regeneration but not on spruce maintenance. Increasing harvesting intensity enabled forest destocking but decreased structure diversity and led to non-sustained yields for the most intensive scenarios. & Conclusion As adaptation measure, we thus recommend moderate group selection harvesting creating 500 m 2 gaps