Drought intensity affects radial growth and recovery of P. schrenkiana at varying elevations in the Western Tianshan Mountains, China

Abstract

As climate change intensifies, forests increasingly face the challenges posed by more frequent and severe droughts. However, the impacts of drought intensity on post-drought growth recovery and compensatory growth in trees remain poorly understood. Understanding the mechanisms through which drought influences tree radial growth and accurately assessing how growth responds to different drought intensities is essential for forecasting forest dynamics. In this study, we used correlation analysis to identify the climatic limiting factors for the radial growth of P. schrenkiana Fisch. & C. A. Mey. (P. schrenkiana) across three elevations in the Western Tianshan Mountains of China. We assessed the impact of drought intensity on radial growth. By analyzing the growth resistance, recovery, and resilience of P. schrenkiana in relation to drought intensity, we quantified post-drought growth trajectories. Our key findings are as follows: 1) Drought stress is the primary factor limiting the radial growth of P. schrenkiana. 2) Tree growth responses vary significantly with elevation and drought intensity. As drought intensity increased, both resistance and recovery decreased. 3) Compensatory growth occurred following moderate and severe droughts at all elevations. However, this was not observed in the first year after extreme droughts. These findings highlight the importance of the first post-drought year in determining the recovery trajectory of P. schrenkiana radial growth.