Topography-dependent climatic sensitivities in spruce tree growth in the Changbai Mountain, Northeast China

Key message We explored topography-dependent variations of spruce (Picea jezoensis var. komarovii) growth in response to climatic change, and abrupt decline in its climatic sensitivities to temperature under global warming in the Changbai Mountain, Northeast China. Variations in the mountain slope direction, being different in radiation intensity and soil moisture, might exert a profound influence on the growth-climate relationship, which potentially brings indeterminacy in sensitivity to temperature under climate warming. To better understand the spatial variation in this influence, we used dendrochronological methods to determine the relationship between the radial growth of spruce (P. jezoensis var. komarovii) and climate in three aspects at an elevation of approximate 1200 m in the Changbai Mountain. The results indicated obvious correlations among the three spruce chronologies, and the radial growth presented more positive correlations with spring temperature (rather than summer or winter temperature), with April temperature on the south-facing slope and negative with precipitation on the north- and west-facing slopes. Despite the sensitivities to temperature were abruptly declined by the increasing temperature, the year- occurrences were inconsistent with records from 1996, 1995 and 1989 on the north (in May), west (in May) and south (in Apr), respectively. The negative relationship with May precipitation has become stronger since 1982 on the north and west for the increasing amount of precipitation. Therefore, given the declined sensitivity of spruce growth to climate warming, which can be shown among three different slopes, the divergent point would be difficult to precisely disentangle in investigating the temporal stability base on the variation in species, habitat and data analytical method.

Automated summary

The study explores the variations of spruce growth in response to climate change in the Changbai Mountain, Northeast China, noting an abrupt decline in sensitivity to temperature under global warming. Different slopes exhibit different relationships between spruce growth and climate, with positive correlations with spring temperature on the south-facing slope and negative correlations with precipitation on the north- and west-facing slopes. Despite the declining sensitivity to temperature, the relationships between spruce growth and climate variables have shifted over time, making it difficult to precisely determine the effects of climate change on spruce growth across different slopes.