Assessing global warming vulnerability of restricted and common plant species in alpine habitats on two oceanic islands

Abstract

Climate change is modifying plant communities and ecosystems around the world. Alpine ecosystems are of special concern on oceanic islands, due to their characteristic higher endemicity rate, small area and undergoing severe climate change impact in the last few decades. During recent decades there has been increasing interest in the effects of climate change on biodiversity and a range of methods have been developed to assess species vulnerability. However, new insights are necessary to obtain useful information for species management on oceanic islands. Here in the alpine area of two oceanic islands (Tenerife and La Palma) we evaluate the drivers that best explain the vulnerability of 63 endemic species along three scenarios, covering recent past to present and two future projections (2041–2060 and 2061–2080. The selected drivers were: loss of fundamental niche area, persistence of fundamental and realized niches, and the adaptive capacity constraints. We assess whether the drivers of risk and vulnerability for common, restricted and rare species are significantly different, and the influence of fundamental niche size. Our results indicate that management must be widely distributed over the species, and not only focus on restricted species. Evidence for this was that drivers directly deriving from climate change showed no significant differences in their impact on the rarity groups identified. Vulnerability depends partially on the fundamental niche size area, showing a more complex picture where constraints on the adaptive capacity of the species have a strong enough influence to modify the effects of the characteristic drivers of climate change.