Sensitivity of Three Dominant Tree Species from the Upper Boundary of Their Forest Type to Climate Change at Changbai Mountain, Northeastern China

Abstract We quantified the growth dynamics and climatic responses of three tree species that have dominated Changbai Mountain: Korean pine (Pinus koraiensis), Yeddo spruce (Picea jezoensis), and Erman's birch (Betula ermanii). Standardization curves and moving correlations were used to assess growth rate trends and analyze changes in growth-climate relationships of trees at their upper forest boundaries and individual species elevation limits, respectively. Contrasting growth patterns were observed between trees at each upper forest boundary and species-specific upper elevation limits. Korean pines and Yeddo spruces grew faster at their upper forest boundaries than at their individual species limits. A higher growth rate of Erman's birches at their forest upper boundary only occurred before 1960. Relative to the strong effect of temperature on tree growth at individual upper elevation limits, the stable effect of precipitation and changing effect of temperature on tree growth were observed at the upper forest boundaries. Temperature increases have had a significantly negative effect on Korean pine and Erman's birch since 1980, whereas temperature increases were associated with Yeddo spruce growth. This study elucidated the differential growth patterns and temporal changes in climate–growth relationships of these species between their upper forest boundaries and elevation limits.