Spatial heterogeneity of tree-growth responses to climate across temperate forests in Northeast Asia

Abstract

Ongoing climate change is having profound impacts on the growth and distribution of trees worldwide. However, there remain substantial gaps in our understanding of how environmental factors influence tree-growth responses to climate at larger scales, which is critical for identifying regions susceptible to the impacts of climate change. In this study, we aimed to reveal the main environmental factors that determine the spatial heterogeneity of tree-growth sensitivity to temperature, precipitation, and drought across temperate forests in Northeast Asia (30–45° N, 124–146° E). Utilising an extensive tree-ring network of 101 chronologies of 22 tree species, across 79 sites, we found that local climate, and especially climate water deficit, plays a dominant role in shaping the spatial heterogeneity of tree-growth sensitivity, while geospatial variables were less important. Our analysis revealed a pervasive pattern of increased tree susceptibility to drought across Northeast Asian forests. Specifically, at sites experiencing high climate water deficit, tree growth was consistently reduced across both broadleaved and coniferous species under conditions of low precipitation, elevated temperatures, and increased dryness during the growing season. Our findings suggest that ongoing climate warming may further negatively affect tree-growth performance, especially at drier sites, across Northeast Asian forests.