Areas Of Climatic Suitability Research Articles

Mycorrhizal fungi as critical biotic filters for tree seedling establishment during species range expansions

AbstractGlobal warming has been shifting climatic envelopes of many tree species to higher latitudes and elevations across the globe; however, unsuitable soil biota may inhibit tree migrations into these areas of suitable climate. Specifically, the role of mycorrhizal fungi in facilitating tree seedling establishment beyond natural species range limits has not been fully explored within forest ecosystems. We used three experiments to isolate and quantify the effects of mycorrhizal colonization and common mycorrhizal networks (CMN) on tree seedling survival and growth across (within and beyond) the elevational ranges of two dominant tree species in northeastern North America, which were associated with either arbuscular mycorrhiza (AMF, Acer saccharum) or ectomycorrhiza (EMF, Fagus grandifolia). In order to quantify the influence of mycorrhiza on seedling establishment independent of soil chemistry and climate, we grew seedlings in soils from within and beyond our study species ranges in a greenhouse experiment (GE) as well as in the field using a soil translocation experiment (STE) and another field experiment manipulating seedling connections to potential CMNs (CMNE). Root length colonized, seedling survival and growth, foliar nutrients, and the presence of potential root pathogens were examined as metrics influencing plant performance across species' ranges. Mycorrhizal inoculum from within species ranges, but not from outside, increased seedling survival and growth in a greenhouse setting; however, only seedling survival, and not growth, was significantly improved in field studies. Sustained potential connectivity to AMF networks increased seedling survival across the entire elevational range of A. saccharum. Although seedlings disconnected from a potential CMN did not suffer decreased foliar nutrient levels compared with connected seedlings, disconnected AM seedlings, but not EM seedlings, had significantly higher aluminum concentrations and more potential pathogens present. Our results indicate that mycorrhizal fungi may facilitate tree seedling establishment beyond species range boundaries in this forested ecosystem and that the magnitude of this effect is modulated by the dominant mycorrhizal type present (i.e., AM vs. EM). Thus, despite changing climate conditions beyond species ranges, a lack of suitable mutualists can still limit successful seedling establishment and stall adaptive climate‐induced shifts in tree species distributions.

Climatic suitability and development potential of facility agriculture at county-level in China

Facility agriculture is a modern cultivation system that utilizes certain facilities and engineering techniques to create a suitable environment for crops growth, which can ensure China's national food security and human nutrition. Both beneficial and limited climatic conditions have influenced the development for facility agriculture. In this study, 12 dominant factors were distilled by using Maximum Entropy model (MaxEnt) to quantify climatic suitability of facility agriculture and its variation in counties across China in 1991–2020. The climatic suitable areas for facility agriculture were mainly distributed in the southern part of Northeast China, North China, central China, southern part of Southwest China, and northern part of East China, especially during 2000–2020. There was a general fluctuating upward trend in the climatic suitability of facility agriculture in traditional advantageous production areas such as Jiangsu, Shandong, Hebei, and Liaoning. Positive trends in the changes of climatic suitability were detected in central and eastern China where rapid development of facility agriculture could be realized through scientific planning and layout. Western provinces such as Gansu, Shaanxi, and Inner Mongolia were highlighted as considerable development potential for facility agriculture, with the perspective of developing energy-saving solar greenhouses in especial. These distribution characteristics and potential changes of climate suitability would help to optimize production layout and achieve green and sustainable development of facility agriculture.

Genotype x Environment Interaction and Stability of Heading Time and Grain Yield of 12 Open Pollinated Sorghum Varieties across Different Agro-ecological Zones in Burkina Faso

Sorghum is the most important crop grown in Burkina Faso and is a staple food for millions of people in rural areas. However, sorghum grain production is mainly from local varieties which are low yielding. Introduced exotic varieties were high yielding but low adopted due to bad grain quality for local dishes. Therefore, it is important to popularize new varieties that meet farmer’s needs. We assessed the agronomic performance and stability of 12 sorghum varieties in different agro-ecological zones in Burkina Faso. Studies were conducted in one location (Kamboinse research station) during 2022 and in six locations (Farako-Bâ, Kamboinse, Fada, Sabou, Zoula and Andemtenga) during rainy season 2023. Twelve sorghum varieties including checks (Kapelga, ICSV 1049) were evaluated in a randomized complete block design with genotypes as studied factors. Agromorphological parameters along with midge damage and number of Striga plants were collected in all the sites. Genotypes, environments and genotype × environment interactions were significant for heading time and grain yield. The varieties had different heading times and different grain yields within environments and across the six environments. The GGE biplot discriminated the study areas into a unique mega-environment for heading time and three mega-environments for yield potential. The majority of varieties yielded more than the average sorghum yield in sub-Sahara Africa, however low yielding varieties were found in environments affected by biotic and abiotic constraints. Some high yielding varieties (Sariaso 43 = 3960.94 kg/ha, 014-SB-EPDU-1004 = 3681.64kg/ha, Sariaso 42 = 3478,52 kg/ha and Sariaso 39 = 3427.73 Kg/ha) were clearly identified in constraintless mega-environments of Kamboinse and Farako-Ba. In conclusion, the GGE biplot analysis revealed that Sariaso 43 was the best genotype that combined suitable heading time and high grain yield across environments. The best performing genotypes for heading time were Sariaso 39 and PR3009B for grain yield. Identified high yielding varieties will be submitted for released and cultivation in suitable agro climatic areas.

Climatically robust multiscale species distribution models to support pronghorn recovery in California.

We combined two climate-based distribution models with three finer-scale suitability models to identify habitat for pronghorn recovery in California now and into the future. We used a consensus approach to identify areas of suitable climate now and future for pronghorn in California. We compared the results of climate models from two separate hypotheses about their historical ecology in the state. Under the migration hypothesis, pronghorn were expected to be limited climatically by extreme cold in winter and extreme heat in summer; under the niche reduction hypothesis, historical pronghorn of distribution would have better represented the climatic limitations of the species. We combined occurrences from GPS collars distributed across three populations of pronghorn in the state to create three distinct habitat suitability models: (1) an ensemble model using random forests, Maxent, classification and regression Trees, and a generalized linear model; (2) a step selection function; and (3) an expert-driven model. We evaluated consensus among both the climate models and the suitability models to prioritize areas for, and evaluate the prospects of, pronghorn recovery. Climate suitability for pronghorn in the future depends heavily on model assumptions. Under the migration hypothesis, our model predicted that there will be no suitable climate in California in the future. Under the niche reduction hypothesis, by contrast, suitable climate will expand. Habitat suitability also depended on the methods used, but areas of consensus among all three models exist in large patches throughout the state. Identifying habitat for a species which has undergone extreme range collapse, and which has very fine scale habitat needs, presents novel challenges for spatial ecologists. Our multimethod, multihypothesis approach can allow habitat modelers to identify areas of consensus and, perhaps more importantly, fill critical knowledge gaps that could resolve disagreements among the models. For pronghorn, a better understanding of their upper thermal tolerances and whether historical populations migrated will be crucial to their potential recovery in California and throughout the arid Southwest.

Diving into warming oceans: Assessing 3D climatically suitable foraging areas of loggerhead sea turtles under climate change

Climate change impacts on marine species have been mainly studied considering only the sea surface despite the fact that most species depend on habitats at different depths. With sea temperatures warming unevenly across depths, identifying critical marine habitats while considering the three-dimensionality of the seascape is a major conservation challenge. Unfortunately, this research field remains largely unexplored and only few examples permit the identification of vertically coherent areas. Here, we developed a climate niche-based framework to delineate critical areas across different depths and assess their consistency over space and time. We use loggerhead sea turtles as a model species to identify climatic suitable areas for the present and future three-dimensional marine space of the Mediterranean Sea, using temperatures from three bathymetric layers of 5 m, 25 m and bottom neritic waters. We analyzed both juvenile and adult sea turtles, which use different depth-related habitats. Our analysis revealed that the coherence among thermal suitable habitats of different depths varied across the different life stages. Although near-surface habitats of juvenile sea turtles spanned across a vast area of the Mediterranean, their water-column habitats were spatially restricted. Near-surface, deep and water-column habitats of adults shared similar distribution patterns. Under future conditions, all types of three-dimensional habitats seemed to primarily maintain thermal stability, however, even opposite changes were predicted for different depths. Our study provides an advanced spatial mapping of sea turtle habitats, highlighting the significance of the three-dimensional marine space and how the selection and combination of specific bathymetric zones may impact patterns in distribution.

Invasion risk of the currently cultivated alien flora in southern Africa is predicted to decline under climate change

Alien species can have massive impacts on native biodiversity, ecosystem functioning, and human livelihoods. Assessing which species from currently cultivated alien floras may escape into the wild and naturalize is essential for efficient and proactive ecosystem management and biodiversity conservation. Climate change has already promoted the naturalization of many alien plants in temperate regions, but whether it is similar in (sub)tropical areas is insufficiently known. In this study, we used species distribution models for 1527 cultivated alien plants to evaluate current and future invasion risks across different biomes and 10 countries in southern Africa. Our results confirm that the area of suitable climate is a strong predictor of naturalization success among the cultivated alien flora. In contrast to previous findings from temperate regions, however, climatic suitability is generally predicted to decrease for potential aliens across our (sub)tropical study region. While increasingly hotter and drier conditions are likely to drive declines in suitability for potential aliens across most biomes of southern Africa, in some the number of potential invaders is predicted to increase under moderate climate change scenarios (e.g. in dry broadleaf forests and flooded grasslands). We found that climatic suitability is expected to decline less for aliens originating from continents with the tropical biome or from the Southern Hemisphere. In addition, we found that the climatically suitable area will decline less for aliens that have already naturalized in the region. While the number of potential invaders may decrease across southern Africa under future climate change, our results suggest that already naturalized aliens will continue to threaten native species and ecosystems.

Climate Change Potentially Leads to Habitat Expansion and Increases the Invasion Risk of Hydrocharis (Hydrocharitaceae).

Climate change is a crucial factor impacting the geographical distribution of plants and potentially increases the risk of invasion for certain species, especially for aquatic plants dispersed by water flow. Here, we combined six algorithms provided by the biomod2 platform to predict the changes in global climate-suitable areas for five species of Hydrocharis (Hydrocharitaceae) (H. chevalieri, H. dubia, H. laevigata, H. morsus-ranae, and H. spongia) under two current and future carbon emission scenarios. Our results show that H. dubia, H. morsus-ranae, and H. laevigata had a wide range of suitable areas and a high risk of invasion, while H. chevalieri and H. spongia had relatively narrow suitable areas. In the future climate scenario, the species of Hydrocharis may gain a wider habitat area, with Northern Hemisphere species showing a trend of migration to higher latitudes and the change in tropical species being more complex. The high-carbon-emission scenario led to greater changes in the habitat area of Hydrocharis. Therefore, we recommend strengthening the monitoring and reporting of high-risk species and taking effective measures to control the invasion of Hydrocharis species.

Empirical estimation of habitat suitability for rare plant restoration in an era of ongoing climatic shifts

Accurate estimates of current and future habitat suitability are needed for species that may require assistance in tracking a shifting climate. Standard species distribution models (SDMs) based on occurrence data are the most common approach for evaluating climatic suitability, but these may suffer from inaccuracies stemming from disequilibrium dynamics and/or an inability to identify suitable climate regions that have no analogues within the current range. An alternative approach is to test performance with experimental introductions, and model suitability from the empirical results. We used this method with the Haleakalā silversword (Argyroxiphium sandwicense subsp. macrocephalum), using a network of out-plant plots across the top of Haleakalā volcano, Hawaiʻi. Over a ~ 5-year period, survival varied strongly across this network and was effectively explained by a simple model including mean rainfall and air temperature. We then applied this model to estimate current climatic suitability for restoration or translocation activities, to define trends in suitability over the past three decades, and to project future suitability through 2051. This empirical approach indicated that much of the current range has low suitability for long-term successful restoration, but also identified areas of high climatic suitability in a region where plants do not currently occur. These patterns contrast strongly with projections obtained with a standard SDM, which predicted continued suitability throughout the current range. Under continued climatic shifts, these results caution against the common SDM presumption of equilibrium between species’ distributions and their environment, even for long-established native species.

A fragile future for pink birds: habitat suitability models predict a high impact of climate change on the future distribution of flamingos

ABSTRACT Climate change is one of the most impactful global phenomena, affecting multiple ecosystems, particularly wetlands and water bodies, as well as important species that depend on these areas. Flamingos are unique and distinctive species that live exclusively in these environments and are highly impacted by any changes in their breeding or non-breeding wetlands. To address and measure the direct impact that future climatic changes could have on the distribution of the six extant species of flamingos, I used citizen science data and climatic variables to construct habitat suitability models. These models were used to predict the future gain or loss of climatic suitability areas in the short, medium, and long term, under four different Shared Socioeconomic Pathways and eight Global Circulation Models. The results predicted that five out of the six species of flamingos will experience continued loss of habitat over the next few decades in all scenarios. Dramatic changes in distribution are expected for all species. The data also indicate a higher impact of climate change on more habitat restrictive species and on wetlands along the borders of their distributions. Finally, the research highlights the importance of combined efforts from public communities, scientists, and policymakers to create mitigation and conservation plans that could avoid the intensification of climate change effects on wetlands and prevent the future reduction of flamingo populations.

Spatial changes to climatic suitability and availability of agropastoral farming systems across Kenya (1980–2020)

Productive global agriculture is under a convergence of pressures, and particularly climate change and population growth. The impact is especially stark in East Africa where crop production is mostly rain-fed and population growth rates are among the highest in the world. Our objective for this study was to understand how climate change and population growth have impacted the size of agropastoral areas across Kenya over 40 years. Climate-suitable areas for all primary crops decreased 28% over the study period. Climate-suitable areas for primary crops increased 3% in highly productive counties, decreased 25% in moderately productive counties, and decreased 62% in low productive counties. Climate-suitable areas over the study period decreased 13% for ranching areas, 21% for dairying areas, 24% for mixed crop and ranching areas, and 28% for mixed crop and dairying areas, while climate-suitable areas for pastoralism increased 12%. Population across Kenya more than tripled over the study period, while population relative to climate-suitable areas for crops increased nearly fourfold, and population relative to climate-suitable areas for pastoralism nearly tripled. Population relative to available climate-suitable areas for crops more than doubled in highly productive counties, increased more than four-fold in moderately productive counties, and was nearly 15 times higher in low productive counties. Examining the cumulative effects of climate change and population growth on agricultural sectors across Kenya can help to develop policies and strategies to reach the UN Sustainable Development Goals.

Modelling of fossil and contemporary data suggest the Broad‐toothed rat (Mastacomys fuscus) currently occupies a small part of its available climatic niche: Implications of paleontological data for conservation of a threatened species

AbstractWe use fossil, sub‐fossil and contemporary records of the Broad‐toothed rat, Mastacomys fuscus, to model changes in its range over the last 21 thousand years. Mastacomys fuscus was exposed to, and flourished in, a much broader range of environmental conditions in the recent past than it occupies today. It also currently occupies a much smaller range than it did in the Late Pleistocene. Apart from a weak response to sea‐level rise in the Holocene, the decline of M. fuscus does not correlate with known climate change. Instead, the contraction of the species' distribution on mainland Australia to high‐elevation areas occurred recently and rapidly. Small changes in the 1000 year BP and present‐day projected distributions imply some contraction of the area of suitable climate to higher elevations of the mainland subspecies M. f. mordicus, up to 2200 m above sea level. However, M. f. mordicus also persists near sea level at Cape Otway (southwestern Victoria) and from sea level to 1500 m above sea level at Barrington Tops (eastern New South Wales, Australia). This suggests suitable habitat may still exist in coastal Victoria and the central Tablelands/Blue Mountains areas. This research highlights the importance and value of using sub‐fossil data to understand changes in the distribution and niche occupation of threatened species as the basis for conservation planning.

Conservation challenges to the useful neotropical palm Babaçu (Attalea pindobassu Bondar) in the face of climate change

Babaçu (Attalea pindobassu Bondar) is a native palm of Brazil's Caatinga Domain. The species has significant socioeconomic value to local communities in the Chapada Diamantina, Northeast Brazil, who employ it for cosmetic, food, and handicraft purposes. We investigated the suitability of habitats of babaçu using Ecological Niche Modeling under current and future climate scenarios, SSP2-4.5 (optimistic) and SSP5-8.5 (pessimistic), to understand the effects of land use and climate change on the potential distribution of A. pindobassu, and to evaluate the effectiveness of the current network of protected areas (PAs) in long-term conservation of the species. The current distribution model predicted climate suitability of 68,754 km², consisting of 8.04% of the Caatinga area. Our results demonstrate a recent suppression of vegetation cover in the areas of climatic suitability. According to the models designed for SSP2-4.5 scenarios, the suitability areas are being reduced over the years when compared to the current model: (i) 2040 reduction of 23.94%; (ii) 2060 reduction of 50.7%; (iii) 2080 reduction of 64.73%; (iv) 2100 reduction of 75.21%. For SSP5-8.5 scenarios, the generated models showed a more accentuated reduction in all evaluated periods: (i) 2040 reduction of 37.27%; (ii) 2060 reduction of 60.46%; (iii) 2080 and 2100 reduction of 100%, indicating probable extinction of the species. A low percentage of climate suitability areas was observed within the PAs, in the current scenario and in the future scenarios. The creation of germplasm banks for ex situ conservation, creation and expansion of PAs, and monitoring of natural populations is crucial to ensure the sustainability of this palm's resources for local communities into the future.

Geographic distribution and climatic niche comparison between diploid and polyploid cytotypes of a South American genus Lessingianthus H.Rob. (Vernonieae, Asteraceae)

The distribution of ploidy levels and their ecological associations were studied using the genus Lessingianthus (Vernonieae, Asteraceae) as a model system. This genus is very complex from a cytogenetic point of view, with high cytotype diversity at the interspecific and intraspecific levels and with a continuous distribution throughout South America. So far, no previous studies have summarized chromosome count data for Lessingianthus or addressed the cytogeography of the genus. In this study, the ploidy levels of Lessingianthus species were determined by chromosome counts during mitosis and ecological niche modelling (ENM) was used to compare the environmental associations of the diploid and polyploid cytotypes. In total, 28 chromosome counts and six ploidy levels (2x, 4x, 6x, 8x, 10x, and 11x) were recorded. Among these counts, the chromosome numbers for three hexaploids with 2 n = 96 (L. parvifolius, L. vepretorum and L. “bolivianensis” sp. ined.) and one decaploid taxon with 2 n = 160 (L. roseus) were reported for the first time. In addition, a new cytotype for L. laniferus (2 n = 6x = 96) was also reported. The cytogeographic analysis resulted in detecting two geographic zones with high diversity of cytotypes and species. The ENMs showed that the areas of climatic suitability of diploids and polyploids are similar in extent, as well as the climatic requirements, showing high values of niche overlap within the environmental space. Our findings suggested that polyploidization in Lessingianthus has not caused expansion to novel environmental conditions and phylogenetic niche conservatism (PNC) may explain the lack of niche differentiation between diploids and polyploids.

Tamarixia radiata global distribution to current and future climate using the climate change experiment (CLIMEX) model

The phloem-limited bacteria, “Candidatus Liberibacter asiaticus” and “Ca. L. americanus”, are the causal pathogens responsible for Huanglongbing (HLB). The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae) is the principal vector of these “Ca. Liberibacter” species. Though Tamarixia radiata Waterston (Hymenoptera: Eulophidae) has been useful in biological control programmes against D. citri, information on its global distribution remains vague. Using the Climate Change Experiment (CLIMEX) model, the potential global distribution of T. radiata under the 2050s, 2070s, and 2090s for Special Report on Emissions Scenarios A1B and A2 was defined globally. The results showed that habitat suitability for T. radiata covered Africa, Asia, Europe, Oceania, and the Americas. The model predicted climate suitable areas for T. radiata beyond its presently known native and non-native areas. The new locations predicted to have habitat suitability for T. radiata included parts of Europe and Oceania. Under the different climate change scenarios, the model predicted contraction of high habitat suitability (EI > 30) for T. radiata from the 2050s to the 2090s. Nevertheless, the distribution maps created using the CLIMEX model may be helpful in the search for and release of T. radiata in new regions.

Geometric morphometrics and ecological niche modelling for delimitation of Triatoma pallidipennis (Hemiptera: Reduviidae: Triatominae) haplogroups

A recent phylogenetic analysis of Triatoma pallidipennis, an important Chagas disease vector in Mexico, based on molecular markers, revealed five monophyletic haplogroups with validity as cryptic species. Here, we compare T. pallidipennis haplogroups using head and pronotum features, environmental characteristics of their habitats, and ecological niche modeling. To analyze variation in shape, images of the head and pronotum of the specimens were obtained and analyzed using methods based on landmarks and semi-landmarks. Ecological niche models were obtained from occurrence data, as well as a set of bioclimatic variables that characterized the environmental niche of each analyzed haplogroup. Deformation grids for head showed a slight displacement towards posterior region of pre-ocular landmarks. Greatest change in head shape was observed with strong displacement towards anterior region of antenniferous tubercle. Procrustes ANOVA and pairwise comparisons showed differences in mean head shape in almost all haplogroups. However, pairwise comparisons of mean pronotum shape only showed differences among three haplogroups. Correct classification of all haplogroups was not possible using discriminant analysis. Important differences were found among the environmental niches of the analyzed haplogroups. Ecological niche models of each haplogroup did not predict the climatic suitability areas of the other haplogroups, revealing differences in environmental conditions. Significant differences were found between at least two haplogroups, demonstrating distinct environmental preferences among them. Our results show how the analysis of morphometric variation and the characterization of the environmental conditions that define the climatic niche can be used to improve the delimitation of T. pallidipennis haplogroups that constitute cryptic species.

Modeling climate change impacts on potential global distribution of Tamarixia radiata Waterston (Hymenoptera: Eulophidae)

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Liviidae), is an efficient vector of “Candidatus Liberibacter” species, the causative agents implicated in citrus greening or huanglongbing (HLB). HLB is the most devastating citrus disease and has killed millions of citrus trees worldwide. Classical biological control using Tamarixia radiata Waterston (Hymenoptera: Eulophidae) against ACP has been successful in some regions. Climatic conditions are critical in determining suitable areas for the geographical distribution of T. radiata. However, paucity of information on climate change impacts on the global spread of T. radiata restricts international efforts to manage ACP with T. radiata. We investigated the potential global distribution of T. radiata using 317 native and non-native occurrence records and 20 environmental data sets (with correlation coefficients (|r| > 0.7)). Using the Maximum Entropy model, these data were analyzed for two shared socioeconomic pathways (SSPs) and two time periods (2030s and 2050s). We showed that habitat suitability for T. radiata occurred in all continents except Antarctica. However, the highly suitable areas for T. radiata were found in parts of the Americas, Asia, Africa and Oceania. The climate suitable areas would increase until the 2050s. The predictions showed that mean temperature of coldest quarter and precipitation of warmest quarter were the most important environmental variables that influenced the distribution of T. radiata. The model reliably predicted habitat suitability for T. radiata, which can be adapted in classical biological control programs to effectively manage ACP in an environmentally friendly manner.

New Distributional Records and Characterization of the Climatic Niche of Lepturges (Lepturges) limpidus Bates, 1872 (Coleoptera, Cerambycidae): Sink or Source Population?

A growing number of cases of the spread and establishment of non-native species outside their previously known ranges has been reported in recent years. Here we report new distributional records of Lepturges (Lepturges) limpidus Bates, 1872 (Cerambycidae) from Argentina and investigate whether these records could represent established populations. We constructed ellipsoid envelope models to characterize climatic niches of L. limpidus, identified areas of climatic suitability, investigated the status of new records as climatic outliers, and evaluated its dependency on its known hostplant as a limiting factor for the beetle distribution. Results indicate widespread climatic suitability in the Neotropical Region, and new records are not outliers with regard to the climatic profile of L. limpidus. Association with its known hostplant is non-dependent, indicating that the species might utilize different hosts plants. New records likely represent established populations, but targeted surveys should be carried out to detect new arrivals and enable the installation of mitigation and control measures.

Risk of infection of white-nose syndrome in North American vespertilionid bats in Mexico

Emerging diseases in wildlife pose challenges for conservation due to their usually rapid spread and high cause of mortality. The transmission of these diseases is a complex ecological process that involves interactions between groups of individuals, particularly in gregarious species. White-nose syndrome, caused by the fungus Pseudogymnoascus destructans, is increasingly infecting species of vespertilionid North American bats causing, in some cases, high population mortality. In this study, we modeled ecological niches projected as potential distributions for three strains of P. destructans (Asian, European and North American) and a group of species of verpertilionid bats in North America. Our model showed that the ecological niches of North American and Asian fungi strains are projected to expand into new geographic areas, with statistical significance between the two strains. In addition, our model identified the presence of all three strains of fungi in areas where the fungus has previously been documented as well as new suitable climatic areas for the establishment of P. destructans in North America: large regions of the central USA and highlands of Mexico in the Peninsula of Baja California, the Sierra Madre Occidental and Oriental, and Transvolcanic Mexican Belt. Our models identified 10 species of vespertilionid bats distributed similarly to P. destructans. Bats had a high risk of infection with WSN and a strong likelihood of dispersing the fungus.

Climate change and human activities promoted speciation of two endangered langurs (François' langur and white-headed langur)

Climate oscillations may drive the divergence of ancestral species through climatic suitability isolation, effective population contraction, and the cessation of gene flow. However, traditional ecological niche models fail to consider gene flow and the historical demography of a species, and thus provide limited insight into how climate oscillations affect species divergence. We analyzed the impact of climate change and human activities on the divergence of two langur species, François' langur (Trachypithecus francoisi) and white-headed langur (T. leucocephalus) using Maxent models and genomic data. Our results indicate that 1) although gene flow occurred between François’ langurs and white-headed langurs during the Last Interglacial (LIG, 140–120 Kya), the two species showed disparate climatic suitability; 2) both taxa were characterized by a decrease in effective population size and a cessation of gene flow during the Last Glacial Maximum (LGM, 26.5–19 Kya), which promoted speciation of the two langurs; and 3) The effective population size and areas of climatic suitability for both species increased from the LGM to the present. More recently, human activities severed the geographical link between the two species, leaving no opportunity for gene flow. Climate oscillation, population isolation, and in situ evolution in refugia appear to have played a critical role in limiting gene flow between these two langur species, however human activities have contributed to species differentiation. Overall, our results demonstrate how climatic oscillations and human activities drive speciation, providing a new perspective on species divergence and conservation.

Analysis of niche shift and potential suitable distributions of Dendrobium under the impact of global climate change.

Dendrobium is a valuable traditional Chinese herb that contains active ingredients such as polysaccharides and alkaloids that have anti-aging, antioxidant, and immunomodulating effects. The appropriate distribution range of Dendrobium should be predicted from the perspective of ecological niche theory in order to preserve and utilize medicinal plant resources. In this study, Dendrobium nobile, Dendrobium officinale, and Dendrobium moniliforme were selected to predict the potential suitable distributions and ecological niche shifts. A comparison of 19 environmental variables of the three Dendrobium species revealed three climatic factors that differed significantly when the species were compared two at a time. The principal component analysis was carried out in order to screen seven climatic factors for ecological niche shift analysis. All three Dendrobium species were found to have a very similar ecological niche, but with a relatively small range of variability regarding certain climatic factors. Finally, the current and future suitable areas for these three Dendrobium species in China were predicted using the MaxEnt model and ArcGIS using the two representative concentration pathways (RCP 2.6 and 8.5). Overall, the analysis of the climatic factors' comparisons, niche shift, and current and future suitable areas of these three Dendrobium species provides a basis for medicinal plant resource conservation and utilization, and our methods could be applied to the study of other similar valuable medicinal plants.