Protecting temperate old‐growth forests as biotic microrefugia amid climate change

Abstract In times of climate change and biosphere degradation, leveraging the potential of forests to support carbon storage and biodiversity is crucial. Besides providing critical habitats for rare and specialist taxa, temperate old‐growth forests are characterized by high biomass, deadwood, and structural complexity, making them a key asset for mitigating climate change. These unique ecological conditions make temperate old‐growth forests more resilient to drought, temperature fluctuations, and other disturbances compared to younger stands. Thus, by maintaining stable microclimatic conditions on the forest floor, old‐growth forests can act as “biotic microrefugia,” buffering understorey species against climatic extremes. Yet, old‐growth forests are not immune to risks: habitat loss, fragmentation, and climate‐driven changes in disturbance regimes threaten their capacity to act as refugia. Conservation efforts must therefore combine the strict protection of remaining temperate old‐growth forest patches with the restoration of connectivity between them, through managing younger stands so they acquire characteristics of old‐growth forest. Functionally connected networks of protected old‐growth forest patches would help to reduce climate impacts on forest species, prevent biodiversity loss, and make a contribution toward reaching the goal of protecting 30% of land by 2030.