Climatic factors of radial growth of Pinus tabulaeformis in eastern Gansu, northwest China based on Vaganov–Shashkin model

Abstract

ABSTRACT Compared with traditional research methods, research based on physiological processes could provide more interactions between the radial growth of trees and climate factors. The Vaganov–Shashkin model (VS-oscilloscope) was applied to simulate tree-ring formation in semi-arid eastern Gansu, China and its response to climate variables during the past several decades. Three simulated tree-ring width series are significantly correlated to the corresponding measured tree-ring chronologies during their common periods (p < 0.001). The growth rate due to soil moisture dominates the radial growth of trees in the main growing season, and growth rate due to temperature limits tree growth at the start and end of the growing season. Simulation results show that soil moisture significantly affects tree-ring width in extremely wide and narrow rings years (p < 0.01). Correlation analysis between measured tree-ring chronologies and monthly climate data and divided periods simulation results show that the limiting effect of soil moisture on the radial growth of Pinus tabulaeformis under warm and dry conditions is significantly enhanced. Our results provide useful knowledge for improving the protection of forests in ecologically fragile areas and mitigating the adverse effects of warmer climate in the future.