Active forest restoration to promote oak regeneration: deadwood manipulation as innovative NBS

Pedunculate oak (Quercus robur L.) is a primary species in European forest ecosystems, playing a key role in supporting biodiversity and maintaining ecosystem functionality. Recent silvicultural strategies increasingly promote the share of oak species in managed forest stands to enhance resilience in the face of climate change. Nevertheless, the natural regeneration of oak stands remains problematic. Despite periodic mast years, successful seedling establishment is rare, hampering the sustainable management and conservation of oak-dominated forests. Here we present an ongoing experiment conducted on 10 hectares of oak-dominated mixed-species forest located on a mesic site. The study tests various combinations of silvicultural interventions, including selective thinning and gap cutting (primarily by removing alien tree species), in conjunction with the creation of deadwood elements (logs, snags, branch piles) derived from the residual material of the forest operations. Such elements were employed as NBS to promote seedlings survival and growth, assuming that these approaches can enhance the local microclimate by reducing thermal stress and improving humidity conditions, as well as provide protection against browsing. We replicated selective thinning and gap cutting in six different areas, artificially creating deadwood elements where planting oak seedlings in their proximity. Control seedlings have been planted in non-intervention areas. Seedling survival, growth, and microclimate conditions are being monitored over the next two seasons. Preliminary findings already indicate differences between the experimental treatments. The outcomes will support the identification of the most effective NBS for promoting oak regeneration, providing useful information for sustainable management practices in European oak forests.