• Energy Research

Current climate and Pleistocene climatic changes are both known to be associated with geographical patterns of diversity. We assess their associations with the European Scarabaeinae dung beetles, a group with high dispersal ability and well-known adaptations to warm environments. By assessing spatial stationarity in climate variability since the last glacial maximum (LGM), we find that current scarab richness is related to the location of their limits of thermal tolerance during the LGM. These limits mark a strong change in their current species richness-environment relationships. Furthermore, northern scarab assemblages are nested and composed of a phylogenetically clustered subset of large-range sized generalist species, whereas southern ones are diverse and variable in composition. Our results show that species responses to current climate are limited by the evolution of assemblages that occupied relatively climatically stable areas during the Pleistocene, and by post-glacial dispersal in those that were strongly affected by glaciations.

This study uses species distribution modeling and physiological and functional traits to predict the impacts of climate change on native freshwater fish in the Murray-Darling Basin, Australia. We modelled future changes in taxonomic and functional diversity in 2050 and 2080 for two scenarios of carbon emissions, identifying areas of great interest for conservation. Climatic-environmental variables were used to model the range of 23 species of native fish under each scenario. The consensus model, followed by the physiological filter of lethal temperature was retained for interpretation. Our study predicts a severe negative impact of climate change on both taxonomic and functional components of ichthyofauna of the Murray-Darling Basin. There was a predicted marked contraction of species ranges under both scenarios. The predictions showed loss of climatically suitable areas, species and functional characters. There was a decrease in areas with high values of functional richness, dispersion and uniqueness. Some traits are predicted to be extirpated, especially in the most pessimistic scenario. The climatic refuges for fish fauna are predicted to be in the southern portion of the basin, in the upper Murray catchment. Incorporating future predictions about the distribution of ichthyofauna in conservation management planning will enhance resilience to climate change.

Abstract.  1. The effects of climate change on species’ ranges have been usually inferred using niche‐based models creating bioclimatic envelopes that are projected into geographical space. Here, we apply an ensemble forecasting approach for niche models in the Neotropical grasshopper Tropidacris cristata (Acridoidea: Romaleidae). A novel protocol was used to partition and map the variation in modelled ranges due to niche models, Atmosphere‐Ocean Global Circulation Models (AOGCM), and emission scenarios.2. We used 112 records of T. cristata and four climatic variables to model the species’ niche using five niche models, four AOGCMs and two emission scenarios. Combinations of these effects (50 cross‐validations for each of the 15 subsets of the environmental variables) were used to estimate and map the occurrence frequencies (EOF) across all analyses. A three‐way anova was used to partition and map the sources of variation.3. The projections for 2080 show that the range edges of the species are likely to remain approximately constant, but shifts in maximum EOF are forecasted. Suitable climatic conditions tend to disappear from central areas of Amazon, although this depends on the AOGCM and the niche model. Most of the variability around the mapped consensus projections came from using distinct niche models and AOGCMs.4. Although our analyses are restricted to a single species, they provide new conceptual and methodological insights in the application of ensemble forecasting and variance partition approaches to understand the origins of uncertainty in studies assessing species responses to climate change in the tropics.

Simulating South American biodiversity The emergence, distribution, and extinction of species are driven by interacting factors—spatial, temporal, physical, and biotic. Rangel et al. simulated the past 800,000 years of evolution in South America, incorporating these factors into a spatially explicit dynamic model to explore the geographical generation of diversity. Their simulations, based on a paleoclimate model on a 5° latitude-longitude scale, result in shifting maps of speciation, persistence, and extinction (or cradles, museums, and graves). The simulations culminate in a striking resemblance to contemporary distribution patterns across the continent for birds, mammals, and plants—despite having no target patterns and no empirical data parameterizing them. Science , this issue p. eaar5452

Climate change and species invasions interact in nature, disrupting biological communities. Based on this knowledge, we simultaneously assessed the effects of climate change on the native distribution of the Amazonian fish Colossoma macropomum as well as on its invasiveness across river basins of South America, using ecological niche modeling. We used six niche models within the ensemble forecast context to predict the geographical distribution of C. macropomum for the present time, 2050 and 2080. Given that this species has been continuously introduced into non-native South American basins by fish farming activities, we added the locations of C. macropomum farms into the modeling process to obtain a more realistic scenario of its invasive potential. Based on modelling outputs we mapped climate refuge areas at different times. Our results showed that a plenty of climatically suitable areas for the occurrence of C. macropomum occurrence are located outside the original basins at the present time and that its invasive potential is greatly amplified by fish farms. Simulations of future geographic ranges revealed drastic range contraction in the native region, implying concerns not only with respect to the species conservation but also from a socio-economic perspective since the species is a cornerstone of artisanal and commercial fisheries in the Amazon. Although the invasive potential is projected to decrease in the face of climate change, climate refugia will concentrate in Paraná River, Southeast Atlantic and East Atlantic basins, putting intense, negative pressures on the native fish fauna these regions. Our findings show that short and long-term management actions are required for: i) the conservation of natural stocks of C. macropomum in the Amazon, and ii) protecting native fish fauna in the climate refuges of the invaded regions.

For each 500-year time interval from 800 Ka (years ago) to the present (1600 time steps), we used a paleoclimate model to assign to each of the 4820 map cells an estimate of the mean temperature of the warmest and coolest quarters and the mean daily precipitation of the wettest and driest quarters. These four factors, on two environmental axes (annual temperature and annual precipitation) characterize the changing climate in each grid cell over the time-course of the simulation.The database consists of the paleoclimate data used in this simulation. It is composed of one text file for each climate variable: (1) minimum annual precipitation, (2) maximum annual precipitation, (3) minimum annual temperature, and (4) maximum annual temperature. Within each file, each row represents a single map cell (4820 in total). The first two columns are the geographical coordinates of each grid cell (latitude and longitude in decimal degrees). The succeeding columns describe the climate variable at each time slice of the series, at successive 500-year intervals. Each column is labeled Tx, where x is thousands of years before present. For example, column “T795.5” of file “PrecipAvgAnnualMax.txt” contains the map cell data for maximum annual precipitation at 795.5kya. Supplement to: Rangel, Thiago F; Edwards, Neil R; Holden, Philip B; Diniz-Filho, José Alexandre F; Gosling, William D; Coelho, Marco Túlio P; Cassemiro, Fernanda A S; Rahbek, Carsten; Colwell, Robert K (2018): Modeling the ecology and evolution of biodiversity: Biogeographical cradles, museums, and graves. Science, 361(6399), eaar5452