A Review of Ungulate Impacts on the Success of Climate-Adapted Forest Management Strategies

Climate change is modifying the dynamics of forests and threatens the supply of ecosystem services from managed forests. In response, managers are developing climate-adapted strategies, mostly focusing on changes in abiotic conditions. Ungulate populations, however, also impact forest integrity and productivity, and the effects of ungulate browsing likely interact with the effects of climate change. This raises the issue of whether climate-adapted strategies will be compatible with abundant ungulate populations. Here, we endeavour to (1) review if/how climate-adapted strategies currently consider ungulates and (2) to highlight how browsing could affect the success of these strategies, using a systematic mapping protocol and available knowledge of ungulate browsing. We identified 57 references discussing climate-adapted forest management that mentioned ungulates, almost exclusively in boreal and temperate forests. The majority (35/57) of these considered browsing to be a threat to climate adaptation. Ungulates could especially prevent the achievement of changes in tree species composition or forest state desired to increase forest resilience. Browsing could also interact with the success of proposed climate-adapted approaches (e.g., nature-based silvicultural approaches and assisted migration), based on known effects of browsing. Potential interactions between large ungulate populations and climate-adapted forest management are sometimes considered but are not a large part of adaptation strategies. More empirical and modeling data would be beneficial, especially on the interactive effect of climate variables and browsing on tree regeneration. Without this, the climate-adapted strategies implemented today could result in future regeneration failures and exacerbate the pressure on forests.