Chaparral Shrub Hydraulic Traits, Size, and Life History Types Relate to Species Mortality during California’s Historic Drought of 2014

摘要: Chaparral is the most abundant vegetation type in California and current climate change models predict more frequent severe droughts that could impact plant community structure. Understanding factors related to species-specific drought mortality essential such changes. We predicted life history type, hydraulic traits, size would be ability of species survive drought. evaluated these a mature chaparral stand during 2014, which has been reported as last 1,200 years. measured tissue water potential, native xylem specific conductivity, leaf percentage loss chlorophyll fluorescence for 11 February was exceptionally dry following protracted Mortality among dominant ranged from 0 93%. Total density reduced 63.4% relative dominance shifted after negatively correlated with fluorescence, but not percent conductivity conductivity. The model best explained included main indicated larger plants had greater survival 2 species. In general, resistance water-stress induced cavitation showed levels. Despite adult resprouters typically being vulnerable cavitation, results suggest their extensive root systems enable them better access soil moisture avoid harmful levels dehydration. These are consistent hypothesis short-term high intensity have strongest effect on shallow-rooted dehydration tolerant species, whereas deep-rooted avoiding fare short-term. Severe can drive changes structure result differential