Yao Ying, Fu Bojie, Liu Yanxu, Zhang Yao, Ding Jingyi, Li Yan, Zhou Sha, Song Jiaxi, Wang Shuai, Li Changjia, Zhao Wenwu
State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China.
State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Natl Sci Rev. 2024 Aug 9;11(10):nwae274. doi: 10.1093/nsr/nwae274. eCollection 2024 Oct.
Compound hot-dry events cause more severe impacts on terrestrial ecosystems than dry events, while the differences in recovery time (ΔRT) between hot-dry and dry events and their contributing factors remain unclear. Both remote sensing observations and eddy covariance measurements reveal that hot-dry events prolong the recovery time compared with dry events, with greater prolongation of recovery time in drylands than in humid regions. Random forest regression modeling demonstrates that the difference in vapor pressure deficit between hot-dry and dry events, with an importance score of 35%, is the major factor contributing to ΔRT. The severity of stomatal restriction exceeds that of non-stomatal limitation, which restricts the vegetation productivity that is necessary for the recovery process. These results emphasize the negative effect of vapor pressure deficit on vegetation recovery during hot-dry events and project an extension of drought recovery time considering elevated vapor pressure deficit in a warming world.
复合型热干事件对陆地生态系统造成的影响比干旱事件更为严重，然而热干事件与干旱事件之间恢复时间的差异（ΔRT）及其影响因素仍不明确。遥感观测和涡度相关测量均表明，与干旱事件相比，热干事件会延长恢复时间，且干旱地区恢复时间的延长幅度大于湿润地区。随机森林回归模型显示，热干事件与干旱事件之间的水汽压亏缺差异（重要性得分35%）是导致ΔRT的主要因素。气孔限制的严重程度超过了非气孔限制，这限制了恢复过程所需的植被生产力。这些结果强调了水汽压亏缺对热干事件期间植被恢复的负面影响，并预测在气候变暖导致水汽压亏缺升高的情况下，干旱恢复时间将会延长。
