Evolutionary correlates of extinction risk in Chinese angiosperm

Abstract

China is widely known for its rich plant diversity, being a home for over 32,000 species of vascular plants. Approximately 11 % of them are threatened and require urgent conservation efforts. Although the major cause of species disappearance is known, the human activity does not affect all species equally. In our study we tested whether, at the family level, the risk of extinction is related to the evolutionary history and the total geographical range of the comprising family species. We gathered threat status data, evolutionary history information and range data for 27,102 Chinese angiosperm species representing 233 families. Using several Bayesian statistical approaches, we found that families with lower diversification rates had smaller geographic ranges, and that family diversification rate and geographic range size were strongly negatively associated with extinction risk. In contrast, the effect of family age on extinction risk, when its indirect effect through geographic range size was accounted for, was significantly positive. Our findings highlight the importance of considering evolutionary history in understanding the extinction dynamics and prioritization of species for protection. Our results imply that a special attention in conservation decisions should be given to species from the families with low diversification rates, old age and limited geographic ranges.