We’ve just published a new multinomial model of projected impacts of climate change on Bay Area vegetation (download here). Maybe the most intriguing result of the model is the prediction that vegetation on north-facing slopes and warmer winter sites (close to the coast) are projected to exhibit more vegetation change in response to future climates. So perhaps these sites will be refugia in the sense that they are occupied by species that are declining in a warmer and drier climate, but they may still be quite dynamic over time.
See the TBC3 web site on our vegetation modeling for applications of the model to counties and landscape units in the Bay Area.