Impact of climate change on the distribution of a giant land snail from South America: predicting future trends for setting conservation priorities on native malacofauna

Abstract

Many land snails are vulnerable to climate change as a consequence of small Distribution ranges and poor dispersal. South America is a diverse region in terms of land snail fauna, but studies about the impacts of climate change on molluscan biodiversity are virtually nonexistent. Bioclimatic models provide an important tool to assess how habitat suitability may change in a warming planet. In this study, we examine potential impacts of climate change on a giant land snail (Megalobulimus sanctipauli) from the Atlantic Forest to predict future shifts in its potential distribution, and to identify protected areas that may contain suitable habitat for setting conservation priorities. Using a maximum entropy algorithm, we modeled the species´potential distribution across South America under current climatic conditions and projected the results onto two climate change scenarios for two time frames. A 2.17 % of South America on the Atlantic Forest was predicted to be currently suitable for the species, comprising the border area among Argentina, Brazil and Paraguay. Prognosis of future distribution showed a trend to a northern retraction, but a southern expansion of current potential range. More than 150 protected areas were identified to contain climatically suitable habitat for the species, but on the less optimistic outlook only ~1,545 km2 of protected areas (0.009 % of South America) would remain suitable for the species by the end of the century. Our findings are expected to improve understanding of climate change impacts on native giant land snails and to contribute in conservation efforts on this malacofauna.