Abstract
The increase of aridity in Mediterranean region limits the ecosystem ability in sequestering carbon and efficiency in using water. Using 20 years (2000-2020) of satellite-derived observations of gross primary productivity (GPP), canopy greenness (NDVI), crop water stress (CWSI), evapotranspiration (ET), and water-use efficiency (WUE), combined with the Standardized Precipitation-Evapotranspiration Index (SPEI), we aimed to (1) identify the earliest drought-sensitive indicators and ecosystem-specific response times, (2) quantify cumulative sensitivities across vegetation types to establish resilience benchmarks, and (3) characterize the temporal propagation pathways through which thermal and physiological stress (CWSI) co-varies with changes in GPP, water flux, and ecosystem efficiency across vegetation types. CWSI is most sensitive satellite-based drought indicator, responding within 0-1 month across most biomes and detecting physiological stress before declines in GPP or NDVI. Croplands and grasslands showed the strongest and fastest responses (|R_max| up to 0.38 with lags of 1-3 months), whereas forests displayed weaker but delayed responses (lags of 4-8 months). The analysis of cumulative sensitivities revealed prolonged drought integration in semi-arid shrublands (6-10 months), intermediate durations in croplands and grasslands (2-4 months), and shorter durations in forests (1-3 months). These results provide an empirical basis for integrating CWSI into regional drought monitoring frameworks and inform adaptive management strategies for Mediterranean ecosystems under future climate extremes.