Abstract
We performed Ecological Niche Models (ENMs) to generate climatically suitable areas for anurans in the Brazilian hotspots, the Atlantic Forest (AF), and Cerrado (CER), considering the baseline and future climate change scenarios, to evaluate the differences in the alpha and beta diversity metrics across time. We surveyed anuran occurrence records and generated ENMs for 350 and 155 species in the AF and CER. The final predictive maps for the baseline, 2050, and 2070 climate scenarios, based on an ensemble approach, were used to estimate the alpha (local species richness) and beta diversity metrics (local contribution to beta diversity index and its decomposition into replacement and nestedness components) in each ~50 × 50 km grid cell of the hotspots. Climate change is not expected to drastically change the distribution of the anuran richness gradients, but to negatively impact their whole extensions (i.e., cause species losses throughout the hotspots), except the northeastern CER that is expected to gain in species richness. Areas having high beta diversity are expected to decrease in northeastern CER, whereas an increase is expected in southeastern/southwestern CER under climate change. High beta diversity areas are expected to remain in the same AF locations as the prediction of the baseline climate, but the predominance of species loss under climate change is expected to increase the nestedness component in the hotspot. These results suggest that the lack of similar climatically suitable areas for most species will be the main challenge that species will face in the future. Finally, the application of the present framework to a wide range of taxa is an important step for the conservation of threatened biomes.
Highlights
Current global climate is approximately 0.85°C warmer than 100 years ago and has a projected increase of 1.5–2°C in the mean temperature by 2100 (IPCC, 2014; Pecl et al, 2017)
The first expected impact of climate change on the Atlantic Forest (AF) and CER anurans is the extinction of 42 species (37 species in the AF and five in the CER) by means of their complete loss of climatically suitable areas by 2050 and 2070
Melo, and Loyola (2014) and Loyola et al (2014) already documented predicted extinctions of some AF anurans by 2050, either in a smaller (Lemes et al, 2014; : nine out of 430 species analyzed – 2.09%) or a higher proportion (Loyola et al, 2014: 52 out of 431 species – ~12%) than that recorded (37 out of 350 species: 10.57%). These percentage differences may be accounted for the differences in the study designs and performed modeling techniques, but the important message here is that if these anurans no longer have physiological, morphological, or behavioral adaptations to accommodate to novel climatic conditions, or whether they are unable to change their particular timing of life-history events to avoid the months with unfavorable climates (Bellard et al, 2012), they are presumed to contract their ranges until extinction due to the fact that they have no climatically suitable area predicted by 2050 and/or 2070
Summary
The use of ENMs to assess the impacts of climate change on the species distribution has been predominantly performed on a species-specific basis (e.g., Martins, Silva, de Marco, & Melo, 2015; Nabout, Oliveira, Magalhães, Terribile, & de Almeida, 2011; Vasconcelos, 2014; Vasconcelos & Nascimento, 2016), there is an increasing use of ENMs to generate richness estimates from each species model of a given taxa when occurrence records are available for a high number of species (e.g., Brown & Yoder, 2015; García- Roselló et al, 2014; Vasconcelos, Rodríguez, & Hawkins, 2012) In such cases, the species individual response is evaluated, but different community ecology metrics can be assessed regarding the influence of different climate change scenarios. We make use of ENMs to generate the climatically suitable area of the species, considering the baseline and future climate change scenarios, in order to answer the following questions: (a) How is climate change expected to change the anuran richness gradients in the AF and CER? (b) Where, in the geographical space, are the areas located with predicted losses and gains in species richness? (c) How is climate change expected to change the location of areas
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
