Drought Timing Differentiates the Drought Responses of Vegetation Growth on the Tibetan Plateau

作者：Zekai Meng, Xiuchen Wu, Yang Li, Xiaona Wang · 发表于：Journal of Geophysical Research Biogeosciences · 年份：2024 · DOI：10.1029/2024jg008179 · 被引用次数：12 · 研究领域：Environmental and Agricultural Sciences、Remote Sensing in Agriculture、Climate variability and models

Abstract The Tibetan Plateau, with its great hydrothermal gradients and diverse ecosystems, is considered vulnerable to climate change. Extreme drought can have detrimental effects on carbon sequestration in terrestrial ecosystems by disrupting plant eco‐hydrological processes. Such effects are presumed to vary and depend on the vegetation types, environmental factors and drought properties. The drought timing has been widely highlighted in drought studies at both regional and site scales. However, the systematic insight into the impact of drought timing on the ecosystem functioning over the Tibetan Plateau remains unclear. In this study, we investigated the responses of vegetation greenness to meteorological drought and attributed them to the drought properties, climatic and edaphic factors. We found that the timing of drought plays a predominant role in regulating vegetation drought responses on the Tibetan Plateau. Notably, we observed significant differences in vegetation responses between late growing season drought and non‐late growing season drought. In addition to drought timing, soil moisture and long‐term hydrothermal conditions also played a significant role. Furthermore, our study revealed that alpine grassland was more sensitive to the drought timing, soil moisture and sand content than woody plants. We discovered a significant interplay between rainfall at hottest quarter and drought timing, with the role of drought timing weakening as the rainfall at hottest qu...