As climate warms, wildfires will become more frequent and intense with longer, drier fire seasons. How ecosystems respond to these changes will shape future ecosystems of California and determine their capacity to take up and store CO2 and regulate hydrologic processes. Resilience of vegetation to wildfire, including both rates of regrowth within vegetation types and transitions among vegetation types, is crucial to understand as these processes strongly affect carbon and water cycles as well as biodiversity and long-term ecosystem resilience. Observational studies have found that warming and associated fire and drought can drive rapid vegetation shifts. Major, widespread impacts are especially likely when multiple disturbances compound; for example, the 2012-2016 extreme drought triggered dramatic tree mortality across the state (Young et al. 2017), which contributed to higher fire severity in subsequent wildfires (Wayman and Safford 2021). There is increasing evidence that recent large wildfires have produced vegetation shifts from forest to montane chaparral (Shive et al. 2018), particularly when combined with increasing aridity (Young et al. 2019).