Responses of radial growth of two coniferous species to climate factors in western Sichuan Plateau, China

Abstract

Based on the method of tree-ring chronology, we established ring-width standard chrono-logies of Abies faxoniana and Sabina saltuaria in Liangtaigou, Lixian County, western Sichuan Province, and their regional composite chronology (RC) to study the responses of radial growth of those two coniferous species to climate change, which provided a basis for the protection and mana-gement of forest ecosystems in this region under the background of global warming. The results showed that the RC contained the common climatic information of two individual chronologies, which had higher signal-to-noise ratio and expressed population signal. The correlation analysis showed that three chronologies had a good consistency in the response to climate factors. All chronologies were significantly correlated with temperature, with S. saltuaria being more sensitive to temperature changes. Relative humidity had stronger limiting effect on both species than precipitation in May and October. After the abrupt warming in 1994, the correlation between ring-width chrono-logy of A. faxoniana and monthly mean temperature shifted obviously from negative to positive in some months, which indicated the radial growth of A. faxoniana showed unstable in response to temperature. However, the radial growth of both species showed different broadening trend and the sensitivity to temperature response was weakened.