Divergent Climate Sensitivities of the Alpine Grasslands to Early Growing Season Precipitation on the Tibetan Plateau

Warming is expected to intensify hydrological processes and reshape precipitation regimes, which closely related water availability for terrestrial ecosystems. Effects of the inter-annual changes on plant growth are widely concerned. However, it not well-known how responds intra-annual regime changes. Here, we compiled reanalysis climate data (ERA5) four satellite-based vegetation indices, including Normalized Difference Vegetation Index (NDVI), Enhanced (EVI), Solar-induced Chlorophyll Fluorescence (SIF), Modified Triangular (MTVI2), evaluate response alpine grasslands (including meadow steppe) change especially regimes Tibetan Plateau. We found monthly over steppe significantly increased in growing season (May–September), but only early (May–June) (MJP) during past decades (1979–2019). The (vegetation indices changes) was dominated by temperature, driven steppe. On scale, temperature sensitivity generally decreased both In increase MJP, mid-growing (July–August) (MGNDVI, MGEVI, MGSIF, MGMTVI2) (p < 0.01) while its 0.01). infer that more MJP may be result enhanced evapotranspiration, at expense soil moisture even induces “drought” season. This elevate community acquisition capacity through altering root mass allocation composition, consequently regulating divergent sensitivities Our findings highlight inadequate regard as an indicator conditions growth, limit our understanding acclimatization plants change.