Blind spots in traditional approaches to conservation prioritization in a climate change context

Climate change affects biodiversity faster than conservation assessments can be conducted. This issue calls for approaches that support decisions on conservation prioritization, such as species phylogenetic relationships or diversity and endemism metrics. However, these traditional approaches often neglect some important aspects, limiting their effectiveness. We used desiccation-tolerant vascular plants (DT plants) to investigate the effectiveness of such approaches to prioritize species and areas for conservation. We used climate data and modeled the distribution of all DT plants recognized to date to evaluate if species phylogenetic relationships can depict similarities in species sensitivity and exposure to climate change, and to evaluate if centers of diversity and endemism for DT plants can indicate regions prone to climate change. We found that the species phylogenetic relationships weakly explains species sensitivity to climate change, although it can, to some extent, describe trends in species exposure to climate change. We also found that centers of diversity and endemism for DT plants are not necessarily the most prone ones to climate change. We suggest a limited effectiveness of phylogenetic relationships and of diversity and endemism metrics for conservation prioritization, once these approaches might overlook vulnerable species and regions exposed to climate change. We discuss that a better understanding of the mechanisms of diversity would help to identify situations in which closely related species show lower ecological differences than distantly related species, when phylogenetic relationships is a more relevant approach in a conservation context. We also suggest that more efficient conservation strategies in centers of diversity and endemism of DT plants should focus on species sensitivity and adaptive capacity to climate change, rather than the magnitude of climate change.