The temperate rainforests distributed along the Pacific coast of North America represent the largest remaining amount of this rainforest type on Earth. Temperate rainforests in this region are characterized by high productivity and relevant ecosystem services such as carbon sequestration and wild salmon runs. These rainforests also show high dependencies on climatic parameters associated with cool, moist climates. Hence, projected increases in temperatures and changes in precipitation patterns by 2080 may severely affect this ecosystem that is already threatened by land‐use pressures.
Two model approaches were applied to investigate shifting climate niches of eight major tree species, two lichen species, and changes in dominant vegetation types. We predicted current and future potential distributions of focal species as well as future vegetation stability by using climate niche and dynamic vegetation models. Climate data from three downscaled general circulation models and two emission scenarios were used to capture uncertainty inherent to climate predictions.
Obtained results show climate niche losses in southern parts of the temperate rainforests and polewards shifts in their northern regions for the majority of modeled species. Coast redwood, in particular, shows high vulnerability to climate change since nearly its entire baseline climate niche is
predicated to be lost. Moreover, potential areas of vegetation stability and future climatic refugia maintaining intact forests were identified.
Main conclusions derived from our modeling results are: (1) protect source populations in intact areas of stable climate as these are best expected to sustain climate change; (2) maintain and restore landscape connectivity especially in highly fragmented areas enabling dispersal; (3) reduce non‐climatic
ecosystem stressors, thus, strengthening ecosystem resilience; and (4) incorporate climate change into reserve management and design by protecting local climate refugia.