Distribution and richness of amphibians under different climate change scenarios in a subtropical region of South America

摘要

Amphibians are a valuable indicator group to study potential impacts of climate change (CC) because reproduction is closely linked to the availability of fresh water. Climate projections for the humid subtropical region of South America predict an increase in temperature towards the southwest and an increasing of precipitation during the rainy season and decreasing during the dry season. In this context, we aimed to predict the changes in the distribution range of amphibian species and the variation in their richness. In addition, we attempted to determine the most vulnerable species in terms of the extent of habitat loss and the overlap of optimal species distributions by contrasting present and future species range. We modelled the current and future distribution of 55 amphibian species using an inductive approach to model the ecological niche with three different algorithms. We used WorldClim data for current climate and IPPC5 climate projections from Global Climate Model for two greenhouse gas concentrations at 2050. Depending on the CC scenario, between 48 and 57% of the species showed a decrease in their optimal distribution, and 9-10% of them are likely to be affected by further population fragmentation. We identified three types of patterns of change in the geographical distribution of the optimal areas: (I) reduction, (II) displacement, and (III) increase in their distribution range. Future new areas with favourable conditions may not be reached due to the low dispersion tendency of amphibians. For this reason, it is important to identify those current favourable areas that are maintained in the different future scenarios. In this sense, this study allows to highlight priority areas for the conservation of the studied species and to identify those being highly vulnerable to the predicted scenarios. Our results contribute to the knowledge of how different future climates scenarios could affect the conservation of the studied amphibian species and provide key information for the development of strategies and public policies for management and biodiversity conservation.