Rarity, geography, and plant exposure to global change in the California Floristic Province

Abstract Aim Rarity and geographic aspects of species distributions mediate their vulnerability to global change. We explore the relationships between rarity geography exposure climate land use change in a biodiversity hotspot. Location California, USA. Taxa One hundred six terrestrial plants. Methods estimated four traits: range size, niche breadth, number habitat patches, patch isolation; three mean elevation, topographic heterogeneity, distance coast. used distribution models measure exposure—predicted continuous suitability within currently occupied habitat—under scenarios. Using regression models, decision‐tree variance partitioning, we assessed rarity, geography, Results Rarity, greenhouse gas emissions scenario explained >35% >61% for exposure. While traits (range size patches) were most important explaining change, (elevation heterogeneity) more strongly associated with species' Main conclusions Species restricted sizes low heterogeneity across predicted be exposed while at elevations loss via However, even some broadly distributed projected lose >70% suitable due if they are geographically vulnerable areas, emphasizing need consider both assessments.