Asymmetric adaptation of dryland vegetation to a warming and drying climate over two decades in Xinjiang, China: Evidence from satellite observations

Arid-zone vegetation may adapt to climate warming and increased precipitation by adjusting photosynthetic capacity and modifying its temperature–precipitation response. However, shifts in optimal temperature (Topt) and precipitation (Popt) values over recent decades remain poorly quantified. In this study, we provide empirical evidence based on satellite-derived vegetation indices and climatic data, showing that from 2000 to 2020, the arid regions of Xinjiang exhibited significant greening, with over 60% of the area showing stable or improving vegetation activity. During this period, Topt increased at a rate of 0.028 °C yr⁻1, while Popt decreased at 0.034 mm yr⁻1. The rising Topt aligns with the trend of increasing air temperatures, whereas the declining Popt contrasts with rising mean precipitation, highlighting the distinct response to the warming and decrease in precipitation trend in regulating vegetation dynamics in arid environments. These findings suggest that vegetation in arid zones is actively acclimating to warming and decrease in precipitation conditions, potentially mitigating the adverse impacts of climate change on ecosystem productivity more than previously anticipated.