Land use changes could modify future negative effects of climate change on old-growth forest indicator species

Abstract

Climate change is expected to have major impacts on terrestrial biodiversity at all ecosystem levels, including reductions in species-level distribution and abundance. We aim to test the extent to which land use management, such as setting-aside forest from production, could reduce climate-induced biodiversity impacts for specialist species over large geographical gradients. We applied ensembles of different kind of species distribution models based on Citizen Science Data (CSD) for six red-listed old-forest indicator species of wood-inhabiting fungi. We tested the effect on species habitat suitabilities of alternative climate change scenarios and varying amounts of forest set-aside from production over the coming century. With the current allocation of 3.6% of forest area set-aside from production in Sweden, habitat suitabilities in set-aside forest initially increased over the first one-two decades in response to maturing forest, before the negative impact of climate change became evident. Overall habitat suitabilities for all six species were projected to decline under climate change scenario RCP4.5 (intermediate-low emissions), with even greater declines projected under RCP 8.5 (high emissions). Increasing the amount of forest set-aside to close to the Aichi Biodiversity Target 11 aim of ≥17% resulted in significant increases in overall habitat suitability, with one species showing an increase. A further increase to 32% forest set-aside resulted in considerably more positive trends, with three out of six species increasing. There is inter-specific variation in the importance of future macro-climate and resource availability on species occurrence. However, large-scale conservation measures, such as increasing resource availability through setting aside forest from production, could reduce future negative effects from climate change, and early investment in conservation is likely to reduce the future negative impacts of climate change on specialist species.