Generate Species Distribution Models Research Articles

Climate change increases threat to plant diversity in tropical forests of Central America and southern Mexico.

Global biodiversity is negatively affected by anthropogenic climate change. As species distributions shift due to increasing temperatures and precipitation fluctuations, many species face the risk of extinction. In this study, we explore the expected trend for plant species distributions in Central America and southern Mexico under two alternative Representative Concentration Pathways (RCPs) portraying moderate (RCP4.5) and severe (RCP8.5) increases in greenhouse gas emissions, combined with two species dispersal assumptions (limited and unlimited), for the 2061-2080 climate forecast. Using an ensemble approach employing three techniques to generate species distribution models, we classified 1924 plant species from the region's (sub)tropical forests according to IUCN Red List categories. To infer the spatial and taxonomic distribution of species' vulnerability under each scenario, we calculated the proportion of species in a threat category (Vulnerable, Endangered, Critically Endangered) at a pixel resolution of 30 arc seconds and by family. Our results show a high proportion (58-67%) of threatened species among the four experimental scenarios, with the highest proportion under RCP8.5 and limited dispersal. Threatened species were concentrated in montane areas and avoided lowland areas where conditions are likely to be increasingly inhospitable. Annual precipitation and diurnal temperature range were the main drivers of species' relative vulnerability. Our approach identifies strategic montane areas and taxa of conservation concern that merit urgent inclusion in management plans to improve climatic resilience in the Mesoamerican biodiversity hotspot. Such information is necessary to develop policies that prioritize vulnerable elements and mitigate threats to biodiversity under climate change.

Comparison of IUCN and species distribution modeling-estimated ranges of shorebirds in Coastal Mainland China

Large areas of unsuitable habitat are often included within the extent of occurrence (EOO) of species, such as the EOO defined by the IUCN (EOOiucn), because the techniques used to estimate the EOO of species often depend on topological methods that do not account for ranges of environmentally suitable habitat. Assessments of the EOO of species are important because they are used in conservation status evaluations. We generated species distribution models in MaxEnt using citizen science data for 8 shorebird species inhabiting China’s coasts from multiple open data sources along with environmental variables to estimate the EOO of these species (EOOm). We then compared EOOm and EOOiucn and assessed the conservation status of these species according to the distribution of national nature reserves. EOOm was generally smaller than EOOiucn for the 8 shorebird species. Over 80 % of the EOOm of the 8 shorebird species did not fall within any national nature reserves, revealing large conservation gaps. Some of unprotected EOOm of these species overlaps with high human footprint area, especially in the Bohai Bay and the Jiangsu–Shanghai coastal region. Our results highlight the need for strengthened conservation effort for unprotected EOOm showing little overlap with national nature reserves, especially in the Bohai Bay and Jiangsu–Shanghai coastal regions.

Diversity of Nearctic Dragonflies and Damselflies (Odonata)

Rarely have studies assessed Odonata diversity for the entire Nearctic realm by including Canada, the United States, and Mexico. For the first time, we explored Odonata diversity in this region according to a definition of natural community assemblages and generated species distribution models (SDMs). Species occurrence data were assembled by reviewing databases of specimens held by significant Odonata repositories and through an extensive search of literature references. Species were categorized as forest-dependent or non-forest-dependent, as lentic or lotic-dependent, and according to conservation status. Predicted distributions were stacked for all species across their entire ranges, including areas outside of the Nearctic. Species richness and corrected weighted endemism (CWE) were then calculated for each grid cell. We found a pattern of greater species richness in the eastern portion of the Nearctic, which can be explained by the higher aquatic habitat diversity at micro and macroscales east of the Rocky Mountains, promoting niche partitioning and specialization. In the Nearctic region, the southeastern US has the highest number of endemic species of dragonflies and damselflies; this degree of endemism is likely due to glacial refuges providing a foundation for the evolution of a rich and unique biota.

Spatial Distribution, Temporal Changes, and Knowledge Gaps in Basking Shark (Cetorhinus maximus) Sightings in the California Current Ecosystem

Among the largest fish species, the basking shark (Cetorhinus maximus) is found circumglobally in temperate and tropical waters. Though historical documents have recorded their presence in the California Current Ecosystem (CCE), basking sharks are now only rarely observed in this part of their range. We compiled recent and historical data from systematic surveys (1962–1997) and other sources (1973–2018) to (i) examine temporal patterns of basking shark sightings in the CCE, and (ii) determine the spatial, temporal, and environmental drivers that have affected basking shark presence and distribution here for the last 50 years. We first calculated variation in basking shark sightings and school size over time. We then generated species distribution models using the systematic survey data and evaluated the performance of these models against the more recent non-systematic sightings data. The sightings records indicated that the number of shark sightings was variable across years, but the number and probability of sightings declined in the mid-1980s. The systematic survey data showed up to nearly 4,000 sharks sighted per year until the 1990s, after which there were no sightings reported. In parallel, there was more than a 50% decline in school size from the 1960s to the 1980s (57.2 to 24.0 individuals per group). During the subsequent decades in the non-systematic data (>1990), less than 60 sharks were sighted per year. There were no schools larger than 10 reported, and the mean school size in the last decade (2010s) was 3.53 individuals per group. Low sea surface temperature and high chlorophyll a concentration increased sightings probability, and prevailing climatic oscillations (El Nino-Southern Oscillation index, North Pacific Gyre Oscillation, Pacific Decadal Oscillation) were also correlated with basking shark presence. Lastly, we observed a significant shift in the seasonality of sightings, from the fall and spring during the systematic survey period to the summer months after the 2000s. We conclude by offering suggestions for future research and conservation efforts; specifically, coordinating the documentation of fisheries mortalities and sightings throughout the Pacific basin would facilitate more robust population estimates and identify sources of mortality. Additionally, monitoring shark fin markets and developing region-specific genetic markers would help ensure that convention on international trade in endangered species (CITES) regulations are being followed.

Connectivity of priority areas for the conservation of large carnivores in northern Mexico

The loss and fragmentation of habitat has negative effects on populations of large carnivores, but ecological corridors that allow dispersal of individuals among habitat remnants mitigate these effects. Our objectives were to identify 1) priority areas for the conservation of three species of large carnivores in northern Mexico, 2) the corridors that can maintain connectivity between them, and 3) pinch points signifying habitat loss that threatens connectivity. We generated species distribution models using MaxEnt and GLM to obtain a consensus model for each species. We applied an inverse function to the probability gradient of the consensus models to calculate the resistance and identify the corridors between priority areas. With Linkage Mapper software, we generated the corridors, calculated their centrality and that of the priority areas, and identified the areas where the corridors are narrower (i.e., pinch points). Finally, we identified the main anthropic fragmentation elements in the most important corridors. We identified 6 priority areas for jaguar, 20 for puma and 21 for black bear, with 5 corridors for jaguar, 22 for puma and 29 for black bear. The pinch points were produced by agricultural fields, human settlements, roads, or combinations of these factors. Depending on the element of fragmentation in each corridor, we propose specific strategies at the pinch points, e.g., applying restoration programs, including wildlife crossings to mitigate road killed cases, promoting payment programs for environmental services or compensation in cases of conflict, to increase the support of local inhabitants for conservation.

Modelling and predicting freshwater mussel distributions in the Midwestern USA

AbstractHistorically diverse and abundant freshwater mussel communities in the Midwestern USA, as elsewhere in the world, are in substantial decline. An understanding of mussel distributions, habitat requirements and biodiversity is required to develop and optimize mussel conservation efforts.Maxent was used to generate species distribution models (SDMs) based on a wide range of environmental variables. Binary predictions were generated using two approaches. Species richness (SR) was estimated through model stacking and evaluated with an independent dataset derived from intensive sampling. Two measures of species endemism were estimated. Factors important for mussel occurrence were identified and geospatial analyses characterized spatial patterns of predicted SR and endemism at multiple spatial scales.SDMs generally performed at ‘fair’ or better levels (0.7 < AUC < 1). Stream size, climate and land use were important to mussel occurrence. SR estimates were positively and significantly correlated with observed SR in a separate dataset. SR and endemism hot and cold spots varied across spatial scales.This study introduces a novel background selection process for aquatic SDMs that considers sampling biases, species records relative to stream size and species' geographical ranges. The results provide valuable insight into species status and distributions, important and actionable factors influencing mussel occurrence, and spatial patterns of highly diverse or endemic regions. This study demonstrates how synthesizing SDMs can inform regional, multi‐species efforts for conserving freshwater mussel diversity.

Protected area networks do not represent unseen biodiversity

Most existing protected area networks are biased to protect charismatic species or landscapes. We hypothesized that conservation networks designed to include unseen biodiversity—species rich groups that consist of inconspicuous taxa, or groups affected by knowledge gaps—are more efficient than networks that ignore these groups. To test this hypothesis, we generated species distribution models for 3006 arthropod species to determine which were represented in three networks of different sizes and biogeographic origin. We assessed the efficiency of each network using spatial prioritization to measure its completeness, the increment needed to achieve conservation targets, and its specificity, the extent to which proposed priority areas to maximize unseen biodiversity overlap with existing networks. We found that the representativeness of unseen biodiversity in the studied protected areas, or extrinsic representativeness, is low, with ~ 40% of the analyzed unseen biodiversity species being unprotected. We also found that existing networks should be expanded ~ 26% to 46% of their current area to complete targets, and that existing networks do not efficiently conserve the unseen biodiversity given their low specificity (as low as 8.8%) unseen biodiversity. We conclude that information on unseen biodiversity must be included in systematic conservation planning approaches to design more efficient and ecologically representative protected areas.

Testing climate tracking of montane rodent distributions over the past century within the Great Basin ecoregion

Geographic ranges of many taxa have shifted poleward or up-slope under warming. Little is known, however, about the consistency of these dynamics among multiple mountains within a species’ geographic range. We assess climate tracking over the past century for four montane rodents, across the Ruby Mountains and Toiyabe Range within the Great Basin ecoregion of western North America. To do this, we generated species distribution models (SDMs, Maxent) in each mountain range during historical (1923–1940) and modern (2005–2015) time periods. Nineteen bioclimatic variables were derived from 800 m resolution monthly PRISM climate group data. SDMs trained on historic occurrences and climate were projected onto modern climates to estimate expected species distributions along each elevational gradient. Occurrence-based Observed Modern SDMs were compared to these Expected Modern SDMs, with congruence between the two representing the degree of climate tracking. Climate tracking predicted up-slope range expansions and contractions in the Ruby Mountains, while stasis or down-slope contractions were predicted in the Toiyabe Range. Observed Modern SDMs rarely matched climate tracking expectations, and the same species showed variable responses among mountains. Deviations are partially explained by changes in the contribution of temperature vs. precipitation over time. Additionally, optimal niche space in the Ruby Mountains shifted in elevation, but shifted in both elevation and latitude in the Toiyabe Range. Our results indicate that data from one elevational gradient may not be predictive of range dynamics elsewhere, even across similar environmental conditions and habitats, even for the same species. Conservation efforts will be better served by strategies that consider both inter- and intraspecific variation in responses to climate change over space and time.

Climate change and bird extinctions in the Amazon

In recent years, carbon dioxide emissions have been potentiated by several anthropogenic processes that culminate in climate change, which in turn directly threatens biodiversity and the resilience of natural ecosystems. Tropical rainforests are among the most impacted biological realms. The Belém endemism center, which is one of the several endemism centers in Amazon, is located in the most affected area within the so-called “Deforestation Arc.” Moreover, this region harbors a high concentration of Amazonian endangered bird species, of which 56% of them are considered to be under the threat of extinction. In this work, we sought to evaluate the current and future impacts of both climate change and deforestation on the distribution of endemic birds in the Belém Area of Endemism (BEA). Thus, we generated species distribution models for the 16 endemic bird species considering the current and two future gas emission scenarios (optimistic and pessimistic). We also evaluated climate change impacts on these birds in three different dispersal contexts. Our results indicate that BAE, the endemic taxa will lose an average of 73% of suitable areas by 2050. At least six of these birds species will have less than 10% or no future suitable habitat in all emission scenarios. One of the main mechanisms used to mitigate the impacts of climate change on these species in the near future is to assess the current system of protected areas. It is necessary to ensure that these areas will continue being effective in conserving these species even under climate change. The “Gurupi Mosaic” and the “Rio-Capim” watershed are areas of great importance because they are considered climate refuges according to our study. Thus, conservation efforts should be directed to the maintenance and preservation of these two large remnants of vegetation in addition to creating ecological corridors between them.

Cryptic speciation in gentoo penguins is driven by geographic isolation and regional marine conditions: Unforeseen vulnerabilities to global change

AbstractAimThe conservation of biodiversity is hampered by data deficiencies, with many new species and subspecies awaiting description or reclassification. Population genomics and ecological niche modelling offer complementary new tools for uncovering functional units of phylogenetic diversity. We hypothesize that phylogenetically delineated lineages of gentoo penguins (Pygoscelis papua) distributed across Antarctica and sub‐Antarctic Islands are subject to spatially explicit ecological conditions that have limited gene flow, facilitating genetic differentiation, and thereby speciation processes.LocationAntarctica and sub‐Antarctic area.MethodsWe identify divergent lineages for gentoo penguins using ddRAD‐seq and mtDNA, and generated species distribution models (SDMs) based on terrestrial and marine parameters.ResultsAnalyses of our genomic data supports the existence of four major lineages of gentoo penguin: (i) spanning the sub‐Antarctic archipelagos north of the Antarctic Polar Front (APF); (ii) Kerguelen Island; (iii) South America; and (iv) across maritime Antarctic and the Scotia Arc archipelagos. The APF, a major current system around Antarctica, acts as the most important barrier separating regional sister lineages. Our ecological analyses spanning both the terrestrial (breeding sites) and marine (feeding sites) realms recover limited niche overlap among the major lineages of gentoo penguin. We observe this pattern to correspond more closely with regional differentiation of marine conditions than to terrestrial macroenvironmental features.Main conclusionsRecognition of regional genetic lineages as discrete evolutionary entities that occupy distinct ecological niches and also differ morphologically should be considered a priority for conservation. Gentoo penguins provide a good example of how conservation policy can be directly impacted by new insights obtained through the integration of larger genomic datasets with novel approaches to ecological modelling. This is particularly pertinent to polar environments that are among the most rapidly changing environments on earth.

La Relevancia de la Conservación del Nicho para la Estimación de Áreas Potenciales de Invasión por Especies de Plantas Exóticas

Niche conservatism is considered a fundamental assumption to generate species distribution models and to estimate areas of invasion risk. These models estimate the climatic requirements of an invasive species and place these requirements outside its native region, thus, if the species has not changed its niche, possible areas of high risk of invasion are identified. This paper analyzes the concept of niche conservatism and its implications of the use of this theoretical assumption in estimating the risk of invasion. It was found that niche conservatism is repeated in many taxonomic groups, is a pattern that varies along a continuum and is affected by the scale or reference point on which it is working. The niche conservatism assumption is not always met, there are exceptions, which should be considered when using species distribution models to predict areas at risk of being invaded, otherwise these areas could be underestimated.

Evolutionary history of Neotropical savannas geographically concentrates species, phylogenetic and functional diversity of lizards

AbstractAimUnderstanding where and why species diversity is geographically concentrated remains a challenge in biogeography and macroevolution. This is true for the Cerrado, the most biodiverse tropical savanna in the world, which has experienced profound biodiversity loss. Previous studies have focused on a single metric (species composition), neglecting the fact that ‘species’ within the biome are often composed of cryptic species. In order to identify biodiversity hotspots more robustly and across multiple dimensions we integrate functional, spatial and new phylogeographic data for the Cerrado lizard fauna by (a) mapping the spatial patterns of species and phylogenetic diversity; and (b) using endemism measures to identify areas of unique diversity. We then quantify the extent to which existing protected areas represent the diversity.LocationBrazilian savanna (Cerrado).MethodsWe generated species distribution models using distribution records for all Cerrado lizard species. These, combined with mitochondrial DNA phylogenies and natural history data, allowed us to map species richness, phylogenetic and functional diversity and phylogenetic and weighted endemism. Phylogenetic endemism maps were then cross‐referenced against protected areas to calculate the amount of evolutionary history preserved within these areas.ResultsThe central region of the Cerrado, a vast and climatically stable plateau, stands out as important under all biodiversity metrics. Including evolutionary relationships in biodiversity assessment, we detected four regional hotspots with high concentration of spatially restricted evolutionary diversity. Protected areas cover only 10% of the Cerrado area and hold 11.64% of the summed phylogenetic endemism of all lizards in the biome.Main ConclusionsWe highlighted both stable (Chapada dos Veadeiros and Serra do Espinhaço plateaus) and environmentally heterogenous regions (Araguaia and Tocantins valleys) as hotspots of evolutionary diversity. The creation and/or manipulation of areas for conservation are essential for the conservation and survival of the rich and endemic lizard fauna of the Cerrado.

Do hotspots fall within protected areas? A Geographic Approach to Planning analysis of regional freshwater biodiversity

Abstract Identification of biodiversity hot spots is necessary for developing conservation strategies. The south‐eastern U.S.A. harbours high aquatic biodiversity; however, this diversity is threatened as a result of anthropogenic activities. We report patterns of fish and mussel biodiversity, locate hotspots of diversity and endemism, and identify gaps in protection of these hotspots. Maxent was used to generate species distribution models for native fish and mussel species in river basins throughout east Texas. Stacked species distribution models were used to assess spatial patterns of biodiversity and examine the concordance between fish and mussel hotspots. A Geographic Approach to Planning analysis was used to identify areas of high conservation concern. Predicted geographical variation in species richness of mussels corresponds to patterns shown in fish; however, there was discordance among endemicity hotspots between the two taxa. Because overall endemicity was low in both groups, species richness is likely to be the more informative measure of biodiversity at these regional scales. While hotspots represent a small percentage of the study area, almost all richness and endemicity hotspots (>95%) in east Texas occur outside of protected areas. The results of this study suggest that protected areas designated based on terrestrial habitat may fail to protect aquatic biodiversity. Studies such as this provide a baseline for development of conservation and management strategies for protection of regional freshwater biodiversity, while also suggesting that designating conservation lands should include consideration of both terrestrial and aquatic biodiversity.

Predicting the potential hybridization zones between native and invasive marmosets within Neotropical biodiversity hotspots

The human-induced introductions of marmoset species (Callithrix genus) threaten the native species persistence within Brazilian biodiversity hotspots. Invasive marmosets can hybridize with native congeners reducing the genetic integrity on native populations. However, no study quantified the spatial extent of these invasions and which species can be impacted by a hybridization process. Here, we predicted the range expansion and hence the potential geographic overlap between Callithrix species, particularly in Atlantic Forest and Cerrado, to discuss management strategies. We hypothesized that marmosets endemic to the Atlantic Forest are more threatened by invasive congeners than other marmosets. We generated species distribution models for six Callithrix species using four algorithms, six environmental layers and 445 georeferenced localities extracted from literature published since 2000. Suitability maps for each species were binarized using a 20-percentile threshold and overlapped to predict invasion and quantify hybridization potential risks. All Callithrix species had potential to expand their range within the Atlantic Forest although suitable habitats for C. flaviceps and C. kuhlii were more limited. C. jacchus and C. penicillata have already expanded their range to different biomes and our model shows that they can spread even further. The potential hybridization zones were identified within the distribution range of all species, and more markedly within Atlantic Forest species ranges. For assuring the ecosystem equilibriums, we urge to prevent the biological invasions and to control the human-induced Callithrix introductions and expansions within Neotropical hotspots.

Species distribution modelling supports “nectar corridor” hypothesis for migratory nectarivorous bats and conservation of tropical dry forest

AbstractAimThe Mexican long‐tongued bat (Choeronycteris mexicana), Mexican long‐nosed bat (Leptonycteris nivalis) and lesser long‐nosed bat (Leptonycteris yerbabuenae) (Phyllostomidae: Glossophaginae) undertake long‐distance migrations from south‐central Mexico to the south‐western United States. It is proposed that these bats migrate along a nectar corridor of columnar cacti and Agave species, but this has not been tested with independent data and the spatiotemporal nature of this relationship is poorly understood. Our goal was to test this nectar corridor hypothesis and determine the relative importance of food plant and abiotic variables to the distribution and seasonal movements of these migratory nectarivores.LocationMexico and the south‐western United States.MethodsWe generated species distribution models (SDMs) of documented food plants for these bats. We then created SDMs for each bat following a model selection approach, using food plant and abiotic predictor variables. We modelled migration pathways for C. mexicana and L. yerbabuenae using circuit theory and seasonal SDMs based on seasonally available food plants.Main conclusionsFood plants were more important than climatic and topographic variables in shaping the distribution of these bats. The most important predictors of distribution were Agave, columnar cacti and species richness of food plants. Species richness of food plants was the most consistently important variable, but the components of this diversity varied by bat species: Choeronycteris mexicana was influenced by Agave and cacti; Leptonycteris nivalis was influenced solely by Agave; Leptonycteris yerbabuenae was influenced more generally by cacti, Agave and C3 plants. Migration models for C. mexicana and L. yerbabuenae provided independent support for the nectar corridor hypothesis and indicate shifts in relative importance of specific food plants throughout the year. These results suggest that conservation of these bats should focus more broadly on management for species richness of food plants, especially in tropical dry forests.

Diversity, Endemism, Species Turnover and Relationships among Avifauna of Neotropical Seasonally Dry Forests

Neotropical seasonally dry forests (NSDF) are widely distributed across Latin America and the Caribbean. They possess important levels of species richness and endemism but few studies have assessed the diversity patterns and ecological relationships between the entire avifauna of these threatened forests. Thus, in order to analyse the macro-ecological patterns and the community structure of NSDF avifaunas, we generated species distribution models describing the current geographical distribution of 1,298 bird species inhabiting NSDF. We assessed species richness gradients in terms of distance from the Equator using both linear and polynomial regressions. Then, based on a matrix composed of the presence or absence of species in 563 quadrants, we performed cluster analyses (considering the Simpson dissimilarity index [βSIM] as a distance measure) to identify the main NSDF regions and describe the avifaunal affinities among them. For the identified groups, we estimated the dissimilarity values, using both an ANOSIM test and the βSIM index. Overall, we observed the lack of an equatorial peak for species diversity of NSDF avifauna in the latitudinal gradient and identified 12 avifaunistic groups. The βSIM index among the NSDF avifaunal groups ranged from 0.05-0.73, showing statistically significant differences (R = 0.894, p = 0.001) in species composition among them. Species shared between two or three NSDF groups comprised a higher proportion (∼38%) than those exclusive to each group (∼23%). Only 35 species were shared between the 12 groups. This information supports a separation of the NSDF avifauna into two major groups (northern and southern), as well as the idea of connections during recent geological time among the NSDF in southeastern South America (the so-called Pleistocene Arc Hypothesis). We provide a scientific framework to contextualise the importance of each NSDF nuclei in terms of their avifauna, supplying an ecological basis for future conservation decisions in order to protect their diversity. —Prieto-Torres, D.A., Rojas-Soto, O.R., Santiago-Alarcon, D., Bonaccorso, E. & Navarro-Siguenza, A.G. (2019). Diversity, endemism, species turnover and relationships among avifauna of neotropical seasonally dry forests. Ardeola, 66: 257-277.

The Need of Species Distribution Models Metadata: Using Species Distribution Model to Address Decision Making on Climate Change

Anthropogenic-induced climate change has already altered the conditions to which species have adapted locally, and consequently, shifts of occurrence areas have been previously reported (Chen et al. 2011). Anticipating the results of climate change is urgent, and using these results efficiently to guide decision-making can help to build strategies to protect species from those changes. Therefore, our objective is to propose the use of climate change impact assessments, obtained through species distribution models (SDMs), to guide decision making. The emphasis will be on data that could help determine the potentially vulnerable species and the priority areas, which could act as climate refuges, as well as wildlife corridors. SDMs are based on species occurrence points, available mainly from biological collections and observations (Franklin 2010). When combined with geospatially explicit layers of abiotic or biotic data (e. g. temperature, precipitation, land use), which defines the ecological requirements of species under study, it can generate species distribution models. These models are projected in the form of maps indicating areas where the species can find the most suitable habitats and, therefore, where one can most likely find them. To support public policies decision, the generation of robust and reliable model is an important factor. A minimum number of six occurrence points is a mandatory requirement, with non-overlapping area as a filter criteria. Unfortunatelly, in Brasil, as well as in Latin America in general, this type of data is scarce. Thus, with SDMs, four types of decision making information data regarding priority species and areas could be obtained (Fig. 1). Size of potential occurrence areas: species that have a small area of occurrence are potentially vulnerable, since they present endemism, usually living in restricted environmental conditions. In this case, any small change in environmental conditions can result in the extinction of the impacted species. Thus, this region needs to be protected. Difference between current and future area: species presenting the most significant reduction in potential areas should be prioritized by decision-makers. This measurement could be used as an indication of vulnerability. Even species that have no predicted area reduction or an increase could be prioritized in management programs due to its role in the complex interaction networks of ecosystem services, such as pollinators, seed dispersers or disease control. These species could be more resilient to network interaction changes due climate, and possibly are better able to provide their services in the extreme unfavorable climate scenarios. Areas that maintain higher species diversity in future scenarios: their protection could be prioritized in restoration and conservation programs. Especially in cases involving multiple species, those areas could be considered as climate refuges by decision-makers. Additionally, for the reconstruction and use of SDM published in peer-reviewed journals, it is necessary that all pieces of information about models, its generation, ensemble methods, data cleaning and data quality criteria applied should be available. The availability of the four above mentioned types of information can help on decision-making strategies aiming the protection of priority species and areas. In conclusion, SDMs present essential information about the present and future impacts of projected climate change and their derived data could be preserved using a standard controlled vocabulary.

Androctonus genus species in arid regions: Ecological niche models, geographical distributions, and envenomation risk.

Aim:The objective of this study was to establish environmental factors related to scorpion species occurrence and their current potential geographic distributions in Morocco, to produce a current envenomation risk map and also to assess the human population at risk of envenomation.Materials and Methods:In this study, 71 georeferenced points for all scorpion species and nine environmental indicators were used to generate species distribution models in Maxent (maximum entropy modeling of species geographic distributions) version 3.3.3k. The models were evaluated by the area under the curve (AUC), using the omission error and the binomial probability. With the data generated by Maxent, distribution and envenomation risk maps were produced using the “ESRI® ArcGIS 10.2.2 for Desktop” software.Results:The models had high predictive success (AUC >0.95±0.025). Altitude, slope and five bioclimatic attributes were found to play a significant role in determining Androctonus scorpion species distribution. Ecological niche models (ENMs) showed high concordance with the known distribution of the species. Produced risk map identified broad risk areas for Androctonus scorpion envenomation, extending along Marrakech-Tensift-Al Haouz, Souss-Massa-Draa, and some areas of Doukkala-Abda and Oriental regions.Conclusion:Considering these findings ENMs could be useful to afford important information on distributions of medically important scorpion species as well as producing scorpion envenomation risk maps.

Current and future distribution of Aedes aegypti and Aedes albopictus (Diptera: Culicidae) in WHO Eastern Mediterranean Region

BackgroundAedes-borne diseases as dengue, zika, chikungunya and yellow fever are an emerging problem worldwide, being transmitted by Aedes aegypti and Aedes albopictus. Lack of up to date information about the distribution of Aedes species hampers surveillance and control. Global databases have been compiled but these did not capture data in the WHO Eastern Mediterranean Region (EMR), and any models built using these datasets fail to identify highly suitable areas where one or both species may occur. The first objective of this study was therefore to update the existing Ae. aegypti (Linnaeus, 1762) and Ae. albopictus (Skuse, 1895) compendia and the second objective was to generate species distribution models targeted to the EMR. A final objective was to engage the WHO points of contacts within the region to provide feedback and hence validate all model outputs.MethodsThe Ae. aegypti and Ae. albopictus compendia provided by Kraemer et al. (Sci Data 2:150035, 2015; Dryad Digit Repos, 2015) were used as starting points. These datasets were extended with more recent species and disease data. In the next step, these sets were filtered using the Köppen–Geiger classification and the Mahalanobis distance. The occurrence data were supplemented with pseudo-absence data as input to Random Forests. The resulting suitability and maximum risk of establishment maps were combined into hard-classified maps per country for expert validation.ResultsThe EMR datasets consisted of 1995 presence locations for Ae. aegypti and 2868 presence locations for Ae. albopictus. The resulting suitability maps indicated that there exist areas with high suitability and/or maximum risk of establishment for these disease vectors in contrast with previous model output. Precipitation and host availability, expressed as population density and night-time lights, were the most important variables for Ae. aegypti. Host availability was the most important predictor in case of Ae. albopictus. Internal validation was assessed geographically. External validation showed high agreement between the predicted maps and the experts’ extensive knowledge of the terrain.ConclusionMaps of distribution and maximum risk of establishment were created for Ae. aegypti and Ae. albopictus for the WHO EMR. These region-specific maps highlighted data gaps and these gaps will be filled using targeted monitoring and surveillance. This will increase the awareness and preparedness of the different countries for Aedes borne diseases.

Climate change versus deforestation: Implications for tree species distribution in the dry forests of southern Ecuador.

Seasonally dry forests in the neotropics are heavily threatened by a combination of human disturbances and climate change; however, the severity of these threats is seldom contrasted. This study aims to quantify and compare the effects of deforestation and climate change on the natural spatial ranges of 17 characteristic tree species of southern Ecuador dry deciduous forests, which are heavily fragmented and support high levels of endemism as part of the Tumbesian ecoregion. We used 660 plant records to generate species distribution models and land-cover data to project species ranges for two time frames: a simulated deforestation scenario from 2008 to 2014 with native forest to anthropogenic land-use conversion, and an extreme climate change scenario (CCSM4.0, RCP 8.5) for 2050, which assumed zero change from human activities. To assess both potential threats, we compared the estimated annual rates of species loss (i.e., range shifts) affecting each species. Deforestation loss for all species averaged approximately 71 km2/year, while potential climate-attributed loss was almost 21 km2/year. Moreover, annual area loss rates due to deforestation were significantly higher than those attributed to climate-change (P < 0.01). However, projections into the future scenario show evidence of diverging displacement patterns, indicating the potential formation of novel ecosystems, which is consistent with other species assemblage predictions as result of climate change. Furthermore, we provide recommendations for management and conservation, prioritizing the most threatened species such as Albizia multiflora, Ceiba trichistandra, and Cochlospermum vitifolium.