Response stability of radial growth of Chinese pine to climate change at different altitudes on the southern edge of the Tengger Desert

Abstract

In recent decades, the climate in northwest China has warmed significantly, especially since the 1980 s, and there has been a period of rapid temperature increase and abundant precipitation since 2010. This has a profound impact on the species structure, distribution and productivity of forest ecosystems. The results of many studies indicate that the response of radial tree growth to global climate change is nonlinear at high altitudes and high latitudes in the Northern Hemisphere. However, altitudinal trends of tree radial growth response to climate change need to be investigated at different locations because of existing local variability in site-specific climatic conditions. Therefore, tree ring chronologies at high (2562 m), middle (2446 m) and low (2328 m) altitudes of Changling Mountain on the southern edge of the Tengger Desert were established to investigate the response to climate change. The results indicated that the interannual variation trends of the basal area increment (BAI) of Chinese pine (Pinus tabulaeformis) at the three altitudes showed first increases, then decreases, and then showed increases again. Trees at the high altitude showed a significant decline in 1997, and those at the middle and low altitudes significantly declined after 1982, while all trees showed growth after 2010. The radial growth of Chinese pine at the three altitudes was mainly restricted by drought stress, but the radial growth at the middle and low altitudes was more restricted by mean temperature and mean maximum temperature. Chinese pine showed unstable responses to climatic factors at the three altitudes, with the middle and high altitudes showing a more stable response to precipitation in the previous year. The drought resistance of Chinese pine first increased and then decreased under drought events, while the resilience first decreased and then increased with climate change. The relationship between trees and climatic factors, as well as the growth pattern and resistance of trees, change with climate change, resulting in differences in survival strategies and adaptability to future climate conditions among trees at the three altitudes.