Work package 4

There is need for a tool to increase our understanding of light-drought effects and - critically - predict biodiversity responses at large scale. In this final WP, the goal is to project forest understorey plant biodiversity changes in response to droughts and other climatic changes across Europe by the end of this century, taking canopy disturbance and novel light regimes into account. Incorporating the novel light regimes has never before been possible in spite of the potentially large effects on forest plant distributions. Now, CanopyChange will provide the necessary data to make this step change possible. For instance, (i) the novel light regimes can more strongly impact growth of some forest-floor species than others and (ii) the declined forest microclimate buffering following canopy disturbance can amplify drought impacts. It is thus more than likely that the incorporation of canopy disturbance will result in very different and more accurate projections of forest biodiversity to climatic changes by the end of this century. Integrating the extensive and diverse data collected by CanopyChange into such refined predictions will be challenging, but now feasible due to the recent developments in the field of joint species distribution modelling (jSDM). Specifically, the hierarchical modelling of species communities (HMSC) framework will be used (Ovaskainen & Abrego, 2020).