Predicting the impacts of climate change on threatened endemic spermatophyte distributions in the Canary Islands

Abstract

Climate change is unequivocal and impacts biodiversity on a global scale. Climatic predictions announced substantial variations in environmental conditions in the near future, with unpredictable effects on the survival of species. In this context, biodiversity hotspots are key regions to preserve, especially oceanic islands that exhibit high endemism levels combined with high extinction rates. In the Canary Islands, the endemic vascular flora is under considerable threat, and its fate under predicted climatic conditions remains unknown. In this master’s thesis, we investigated the impact of climate change on 69 threatened spermatophytes species distributions endemic to the Canary Islands and assessed the effectiveness of the Canarian protected area network. We used ensemble of small models to (i) predict the suitable range of such species under three future climatic scenarios, from the most optimistic (SSP1-2.6) to the worst-case scenario (SSP5-8.5) and a midway between (SSP3-7.0), and (ii) assess the overlap between predicted suitable ranges with the currently protected area circumscription. The models projected an average loss of 78 %, 85 % and 82 % of the suitable area and an average elevation shift upward of 103 meters, 230 meters and 223 meters for all species under SSP1-2.6, SSP3-7.0 and SSP5-8.5, respectively. Current protected areas were found to cover 61.5 % of the present suitable range and 61.5 %, 63.8 % and 62.5 % of the predicted suitable ranges under SSP1-2.6, SSP3-7.0 and SSP5-8.5, respectively. As expected for insular biodiversity, the loss of most endemic species is likely to occur in the coming decades. For that reason, effective conservation measures and drastic reductions of our carbon emissions are essential.