Date Published: June 13, 2019
Publisher: Public Library of Science
Author(s): Maria Teresa Ferreira, Pedro Cardoso, Paulo A. V. Borges, Rosalina Gabriel, Eduardo Brito de Azevedo, Rui Bento Elias, Mary Peacock.
Climate change is causing shifts in species distributions worldwide. Understanding how species distributions will change with future climate change is thus critical for conservation planning. Impacts on oceanic islands are potentially major given the disproportionate number of endemic species and the consequent risk that local extinctions might become global ones. In this study, we use species climate envelope models to evaluate the current and future potential distributions of Azorean endemic species of bryophytes, vascular plants, and arthropods on the Islands of Terceira and São Miguel in the Azores archipelago (Macaronesia). We examined projections of climate change effects on the future distributions of species with particular focus on the current protected areas. We then used spatial planning optimization software (PRION) to evaluate the effectiveness of protected areas at preserving species both in the present and future. We found that contractions of species distributions in protected areas are more likely in the largest and most populated island of São Miguel, moving from the coastal areas towards inland where the current protected areas are insufficient and inadequate to tackle species distribution shifts. There will be the need for a revision of the current protected areas in São Miguel to allow the sustainable conservation of most species, while in Terceira Island the current protected areas appear to be sufficient. Our study demonstrates the importance of these tools for informing long-term climate change adaptation planning for small islands.
Protected areas are created nowadays not only to maintain iconic landscapes and seascapes and ensure biodiversity conservation, but also to play a key part in the mitigation of, and/or adaptation to, climate change . A common assumption is that successful conservation within protected areas is possible when these areas are managed to buffer against the processes that threaten them . However, it is becoming clear that in addition to providing sustainable management of habitats and ecosystems, effective conservation strategies need to mitigate the impacts of climate change . The main question is whether species range retention areas or critical areas for dispersal are covered by existing protected areas and whether there are tools to identify critical areas for biodiversity conservation in a changing climate . Furthermore, the threats imposed by climate change often compound conventional threats associated with habitat degradation, pollution, poaching, and spread of alien invasive species . Conservation planning is thus facing a major challenge: the need to identify climate refugia for conservation  as well as to account for new and dynamic threats emerging from climate change and their interactions with other stressors .
Of the 179 analyzed species, 23 were SIE’s 13 of which are coastal species. The results from overlaying the species potential distributions with the current protected areas showed that the average coverage percentage is 53±16%, with only the Bryophytes in Terceira Island having values above 44±13%, while the remainder values average around 30% for the three taxonomic groups (Table 1).
The proportion of species climate potential distribution inside the current PA’s was found to increase from the 1961–1990 period to the 2080–2099 period (Table 1), especially for Terceira. This happens because the potential distribution of the species actually decreases from one time period to the other, and proportionately the percentage of the species distribution that is covered by the current PA’s increases. However, when we compare the species potential distribution only inside the PA’s (Table 2), there is actually a decrease by over 33±5% for Terceira Island for example. This shows how important it is to have all the information possible in order to make well-founded recommendations when it comes to PAs.
In this work, our model projections for most endemic species studied in Terceira and São Miguel Islands suggests that there will be a decrease in distribution with climate change. This has implications for the conservation of these species, being at risk of either disappearing or reducing their distribution dramatically. Evaluating the suitability of the current protected areas has shown that these may not meet the needs of species in the future, especially on São Miguel. This type of analysis can be done for other islands of the Azores as well. We have shown that tools like the software PRION useful for delineating changes to species distributions under climate change. Climate change will likely affect species future distributions and the optimization of protected areas is a necessity in global change scenarios. Reaching the decision makers with this information is therefore of the upmost importance.