Responses of Mediterranean-climate vegetation to drought and climate change across scales in California

California's climate is projected to have more droughts and heatwaves in the future. A combination of heat and drought stress may significantly affect vegetation health of the Mediterranean ecosystems than drought stress alone. Based on multi-source remote sensing and surface data, we investigated the impacts of drought and climate change on the Mediterranean-climate vegetation of California at different scales, i.e. the entire state, southern California, and Los Angeles urban area. For entire California, we find that a hydroclimatic dipole regulated by El Niño-Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) intensifies the aridity in southern California compared to the north. At a regional scale of southern California, we utilized a bootstrapping regression model to analyze the geographical influences on the relationships between vegetation and drought. Results suggest a warmer climate can significantly increase vegetation sensitivity to drought. In addition, soil texture and elevation seem to also play an important role in adjusting the wildland vegetation susceptibility to drought. In the Los Angeles urban area, we find socioeconomic conditions is the decisive influence in intensifying or mitigating the vegetation response to water-scarce seasons and years. The projected hotter climate in the 21^st century may reshape the future landscapes of the coupled human-natural system in California by exacerbating drought severity and duration, differentiating mortality, and increasing wildfires.