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

Abstract

Aim: 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. Location: Sweden. Methods: We applied ensembles of species distribution models based on citizen science data for six species of red-listed old-forest indicator fungi confined to spruce dead wood. 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. Results: With 3.6% of forest area set-aside from production and assuming no climate change, overall habitat suitabilities for all six species were projected to increase in response to maturing spruce in set-aside forest. However, 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 16% 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 of six species increasing. Main conclusions: There is interspecific variation in the importance of future macroclimate 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.