The marked increase in drought extreme frequency in drylands raises concerns about the stability and sustainability of forest productivity. However, the responses of forests to climate extremes in drylands such as Inner Asia have received limited attention thus far despite their importance for forest sustainability and ecosystem services. After examining the changes on tree growth observed during and after droughts as well as the relations of growth increments associated with climate wetness at 32 forest sites across Inner Asia, we found that the growth compensation by climate wetness can reach 278% in Inner Asia (tree growth increasing 0.39 mm during climate wetness vs decreasing 0.14 mm during droughts), 2.5 times higher than the global average of 93%, reflecting the adaptation of forests in water-deficient areas to high-frequency climate extremes. However, we further observed fading extra-compensation of climate wetness on tree growth since the 1980s, namely decreasing growth enhancements occurring during wet periods, while significantly increasing growth declines occurring during dry periods. Fading extra-compensation on tree growth was leading to persistent and pervasive declines on tree growth rate in the study area. Our results indicate that this fading extra-compensation of climate wetness will weaken the resistance of forests to droughts and potentially reduce the carbon sink strength of forests in Inner Asia.

旱地干旱极端频率的显着增加引发了人们对森林生产力稳定性和可持续性的担忧。然而，尽管森林对森林可持续性和生态系统服务的重要性，但迄今为止，森林对内亚等旱地极端气候的反应受到的关注有限。在研究了干旱期间和之后观察到的树木生长变化以及内亚 32 个森林地点与气候湿度相关的生长增量关系后，我们发现内亚气候湿度的生长补偿可以达到 278%（树在气候潮湿期间增长增加 0.39 毫米，而在干旱期间减少 0.14 毫米），比全球平均水平 93% 高 2.5 倍，反映了缺水地区的森林对高频极端气候的适应。然而，我们进一步观察到自 1980 年代以来气候湿度对树木生长的额外补偿逐渐减弱，即在潮湿时期发生的生长增强减少，而在干旱时期发生的生长下降显着增加。减少对树木生长的额外补偿导致研究区域树木生长率持续和普遍下降。我们的研究结果表明，这种减弱的气候湿度额外补偿将削弱森林对干旱的抵抗力，并可能降低内亚森林的碳汇强度。而在干旱时期发生的增长下降显着增加。减少对树木生长的额外补偿导致研究区域树木生长率持续和普遍下降。我们的研究结果表明，这种减弱的气候湿度额外补偿将削弱森林对干旱的抵抗力，并可能降低内亚森林的碳汇强度。而在干旱时期发生的增长下降显着增加。减少对树木生长的额外补偿导致研究区域树木生长率持续和普遍下降。我们的研究结果表明，这种减弱的气候湿度额外补偿将削弱森林对干旱的抵抗力，并可能降低内亚森林的碳汇强度。