High Habitat Suitability Research Articles

East‒West genetic differentiation across the Indo-Burma hotspot: evidence from two closely related dioecious figs

BackgroundUnderstanding biodiversity patterns and their underlying mechanisms is of interest to ecologists, biogeographers and conservationists and is critically important for conservation efforts. The Indo-Burma hotspot features high species diversity and endemism, yet it also faces significant threats and biodiversity losses; however, few studies have explored the genetic structure and underlying mechanisms of Indo-Burmese species. Here, we conducted a comparative phylogeographic analysis of two closely related dioecious Ficus species, F. hispida and F. heterostyla, based on wide and intensive population sampling across Indo-Burma ranges, using chloroplast (psbA-trnH, trnS-trnG) and nuclear microsatellite (nSSR) markers, as well as ecological niche modeling.ResultsThe results indicated large numbers of population-specific cpDNA haplotypes and nSSR alleles in the two species. F. hispida showed slightly higher chloroplast diversity but lower nuclear diversity than F. heterostyla. Low-altitude mountainous areas of northern Indo-Burma were revealed to have high genetic diversity and high habitat suitability, suggesting potential climate refugia and conservation priority areas. Strong phylogeographic structure and a marked east‒west differentiation pattern were observed in both species, due to the interactions between biotic and abiotic factors. Interspecific dissimilarities at fine-scale genetic structure and asynchronized historical dynamics of east‒west differentiation between species were also detected, which were attributed to different species-specific traits.ConclusionsWe confirm hypothesized predictions that interactions between biotic and abiotic factors largely determine the patterns of genetic diversity and phylogeographic structure of Indo-Burmese plants. The east‒west genetic differentiation pattern observed in two targeted figs can be generalized to some other Indo-Burmese plants. The results and findings of this work will contribute to the conservation of Indo-Burmese biodiversity and facilitate targeted conservation efforts for different species.

Predicting the current and future distribution of pine woodland specialist plants in the Cairngorms National Park

The Caledonian pine forests of Scotland have declined significantly over the past century largely due to clearance for timber, fuel and grazing land. Approximately 1% of these native pinewoods remain from their historic extent, with a stronghold in the Cairngorms National Park. Creeping Lady’s-Tresses Goodyera repens (L.) R. Br., One-Flowered Wintergreen Moneses uniflora (L.) A. Gray and Twinflower Linnaea borealis L. favour this habitat, meaning that the clearance of pine woodland has resulted in widespread declines. There are multiple plantation schemes underway in the Cairngorms to reforest the Highlands, such as Cairngorms Connect, partly with the intent of assisting the recovery of pine woodland specialists. This study uses Maximum Entropy modelling (MaxEnt) to create species distribution models (SDMs), firstly to predict the current distribution for these species; thus, enabling land managers in the Cairngorms to target surveys with the hope of finding new populations. Secondly, future distribution models are created using different emissions scenarios to predict the regions of maximum habitat suitability for the study species, with the aim of visualising where pine woodland should be planted to ensure long-term habitat viability. The results showed that there are regions in the north and east of the Cairngorms which have the highest habitat suitability, currently and in the future. The creation of habitat corridors between these two regions should be a priority to prevent isolation between populations of pine woodland specialists. The high emissions pathway could increase the likelihood of isolation by significantly decreasing the habitat suitability between the most suitable areas.

Change in habitat suitability of the invasive Snowflake coral (Carijoa riisei) during climate change: An ensemble modelling approach

Global species range dynamics are intrinsically influenced by the interplay between human activities and climate compatibility. Snowflake coral (Carijoa riisei) is a soft octacoral species that belongs to the family Clavulariidae and can rapidly grow to colonise new habitats. This species has successfully colonised numerous habitats, displacing native species and disrupting the ecological balance in the introduced habitats. Recent investigations into species invasions in aquatic ecosystems suggest that anthropogenic activities and climate change will accelerate the introduction, establishment, and spread of invasive species to new habitats. In this study, we utilised ensemble species distribution modelling to investigate shifts in the invasive potential of Snowflake coral in current and future climatic settings on a global scale. Future distribution was forecasted using four Representative Concentration Pathways (RCPs 2.6, 4.5, 6.0, and 8.5) across two periods (2040–2050 and 2090–2100). The results accurately predicted the known distributional range of the species. Temperature, distance to the port, and bathymetry were identified as the three most significant predictor variables. The low and medium habitat suitability regions increased in all scenarios and periods. In the high habitat suitability category, only RCP 4.5 and RCP 6.0 in the 2090–2100 period exhibited an increase in percentage area. Under the worst-case climate scenario, RCP 8.5 (2090–2100), the high-suitability regions displayed a surprising decline in area percentage, which can be attributed to the temperature thresholds of the species. Our findings indicate that the species has a greater potential to spread under current climatic conditions than previously reported, and its expansion may further accelerate in the future. This highlights the urgent need for more intensive surveys employing advanced detection tools and the implementation of proactive management measures to protect vulnerable ecosystems that could be impacted by this species.

Ensemble species distribution modeling of Culex tarsalis (Diptera: Culicidae) in the continental United States.

West Nile virus (WNV) is the primary mosquito-borne disease in the United States and has had case reports every year since its introduction in 1999. As such, it is critical that we characterize the distribution of WNV vectors. Estimates of Culex tarsalis Coquillett species distribution, a major WNV vector, are scarce. We used ensemble distribution modeling to estimate habitat suitability for this species across the contiguous United States by consolidating presence data from four publicly available mosquito trapping data servers. The central plains region and much of the western US were estimated to have high habitat suitability. We identified multiple metrics of temperature and precipitation to be important in predicting the occurrence of Cx. tarsalis in a given geographic area. Furthermore, we observed habitat suitability for Cx. tarsalis to be significantly higher in areas with a high incidence of West Nile neuroinvasive disease compared to areas with low WN disease incidence, suggesting that Cx. tarsalis is present in regions with a high incidence of disease.

Suitable Habitats for Cicadella viridis and Evacanthus interruptus (Hemiptera: Cicadellidae) with Global Climate Change

Abstract Cicadella viridis (L.) and Evacanthus interruptus L. (Hemiptera: Cicadellidae) are two of the most important leafhopper pests worldwide. Identifying habitat suitability areas of these species could be useful for their management. This study used the MaxEnt model to predict the current and future global habitat suitability areas of these species based on distribution and associated environmental data. The model showed that isothermality and the mean temperature of the driest quarter of the year were the most important environmental factors affecting the distribution of C. viridis and E. interruptus. Europe and southern China are the current primary habitat suitability areas for the two species. The high habitat suitability areas for C. viridis are also concentrated in these areas, whereas the high habitat suitability areas for E. interruptus are mainly found in western Europe. Under future climate change scenarios, the area of the two species habitat suitability areas increases, and the high habitat suitability areas for C. viridis decrease. However, the high habitat suitability areas for E. interruptus increase in 2041–2060 shared socioeconomic pathways 585 (ssp585) but decrease in 2041–2060 and 2061–2080 shared socioeconomic pathways 126 (ssp126). It is necessary to develop measures to monitor these species within habitat suitability areas, especially in high habitat suitability areas, to reduce economic losses.

Global Distribution of Culex tritaeniorhynchus and Impact Factors

Culex tritaeniorhynchus is the primary vector of Japanese encephalitis (JE) and has a wide global distribution. However, the current and future geographic distribution maps of Cx. tritaeniorhynchus in global are still incomplete. Our study aims to predict the potential distribution of Cx. tritaeniorhynchus in current and future conditions to provide a guideline for the formation and implementation of vector control strategies all over the world. We collected and screened the information on the occurrence of Cx. tritaeniorhynchus by searching the literature and online databases and used ten algorithms to investigate its global distribution and impact factors. Cx. tritaeniorhynchus had been detected in 41 countries from 5 continents. The final ensemble model (TSS = 0.864 and AUC = 0.982) indicated that human footprint was the most important factor for the occurrence of Cx. tritaeniorhynchus. The tropics and subtropics, including southeastern Asia, Central Africa, southeastern North America and eastern South America, showed high habitat suitability for Cx. tritaeniorhynchus. Cx. tritaeniorhynchus is predicted to have a wider distribution in all the continents, especially in Western Europe and South America in the future under two extreme emission scenarios (SSP5-8.5 and SSP1-2.6). Targeted strategies for the control and prevention of Cx. tritaeniorhynchus should be further strengthened.

Estimation of climate-induced increased risk of Centaurea solstitialis L. invasion in China: An integrated study based on biomod2

IntroductionInvasive alien plants (IAPs) are major hazards to biodiversity, human health, and the agricultural economy. As one of the most aggressive species of IAPs, the distribution area of Centaurea solstitialis L. has increased exponentially in the past two years since its invasion into Xinjiang, China, in July 2014. Predicting the potential geographic distributions (PGDs) of C. solstitialis in China can provide theoretical support for preventing the continued spread of this weed.MethodsIn this study, based on 5,969 valid occurrence records of C. solstitialis and 33 environmental variables, we constructed an ensemble model to predict suitable habitats for C. solstitialis under climate change scenarios.ResultsOur results showed that the mean true skill statistic (TSS) values, area under the receiver operating characteristic (ROC) curve (AUC), and Cohen’s Kappa (KAPPA) for the ensemble model were 0.954, 0.996, and 0.943, respectively. The ensemble model yielded more precise predictions than those of the single model. Temperature seasonality (Bio4), minimum temperature of the coldest month (Bio6), precipitation of the driest month (Bio14), and human influence index (HII) have significantly disrupted the PGDs of C. solstitialis in China. The total (high) suitability habitat area of C. solstitialis in China was 275.91 × 104 (67.78 × 104) km2, accounting for 71.26 (7.06)% of China. The PGDs of C. solstitialis in China under the current climate were mainly in East China (Shandong, Jiangsu, Shanghai, Zhejiang, and Anhui), Central China (Henan, southwestern Shanxi, southern Shaanxi, southern Gansu, Hubei, Hunan, Jiangxi, Chongqing, and Guizhou), and South China (southern Tibet, eastern Sichuan, Yunnan, Guangxi, Guangdong, Fujian, and Taiwan). Under future climate scenarios, the total suitability habitat area for C. solstitialis will expand, whereas the high suitability habitat area will decrease.DiscussionThe main manifestation is that the shift of southeast China into a moderate suitability habitat, and the total suitability habitats will be extended to northwest China. More focus needs to be placed on preventing further spread of C. solstitialis in northwest China.

Contrasting ecological information content in whaling archives with modern cetacean surveys for conservation planning and identification of historical distribution changes.

Many species are restricted to a marginal or suboptimal fraction of their historical range due to anthropogenic impacts, making it hard to interpret their ecological preferences from modern-day data alone. However, inferring past ecological states is limited by the availability of robust data and biases in historical archives, posing a challenge for policy makers . To highlight how historical records can be used to understand the ecological requirements of threatened species and inform conservation, we investigated sperm whale (Physeter macrocephalus) distribution in the Western Indian Ocean. We assessed differences in information content and habitat suitability predictions based on whale occurrence data from Yankee whaling logs (1792-1912) and from modern cetacean surveys (1995-2020). We built maximum entropy habitat suitability models containing static (bathymetry-derived) variables to compare models comprising historical-only and modern-only data. Using both historical and modern habitat suitability predictions we assessed marine protected area (MPA) placement by contrasting suitability in- and outside MPAs. The historical model predicted high habitat suitability in shelf and coastal regions near continents and islands, whereas the modern model predicted a less coastal distribution with high habitat suitability more restricted to areas of steep topography. The proportion of high habitat suitability inside versus outside MPAs was higher when applying the historical predictions than the modern predictions, suggesting that different marine spatial planning optimums can be reached from either data sources. Moreover, differences in relative habitat suitability predictions between eras were consistent with the historical depletion of sperm whales from coastal regions, which were easily accessed and targeted by whalers, resulting in a modern distribution limited more to steep continental margins and remote oceanic ridges. The use of historical data can provide important new insights and, through cautious interpretation, inform conservation planning and policy, for example, by identifying refugee species and regions of anticipated population recovery.

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.

Semi-quantitative risk assessment of marine mammal oil exposure: A case study in the western Gulf of Mexico

Marine mammals are highly vulnerable to oil spills, although the effects at both individual and population levels are not fully understood. A first approximation to evaluate the possible consequences of oil spills on marine life is using ecological risk assessments, which are analytical tools used to assess the likelihood of adverse environmental effects due to exposure to stressors derived from human activities. We developed a semi-quantitative framework to evaluate the risk of oil spill exposure on marine mammals that combines the likelihood of exposure based on species-specific biological and ecological traits, and the feasibility of encounter, which considers not only the overlap between the distribution of the species and the total affected area by a spill but also considers the distribution of spilled oil within this area, thus reducing the uncertainty in the estimate. We applied our framework to assess the risk of exposure of eight cetaceans to scenarios of large heavy oil (API gravity<22) spills originating from three hypothetical deep-water wells in the western Gulf of Mexico. High habitat suitability areas obtained using the maximum entropy (MaxEnt) modeling approach were used as a proxy for the geographic regions where each species is likely to be distributed, and oil spill scenarios were generated using numerical models incorporating transport, dispersion, and oil degradation. The analysis allowed identifying those species for which there is a significant risk of exposure in each spill scenario. However, our results suggest that the risk does not appear to be high for any species under any scenario. The information generated by our risk assessment is key to developing management plans in those areas of the Gulf of Mexico where deep-water activities of the hydrocarbon industry are currently being developed or planned.

Identification of Wetland Conservation Gaps in Rapidly Urbanizing Areas: A Case Study in Zhengzhou, China

Exploring protected area (PA) siting from a biodiversity perspective is critical in mitigating human impacts on ecosystems. This paper used the MaxEnt model to predict the geographic distribution patterns of wetland species in Zhengzhou and the environmental factors affecting species’ habitat selection. Environmental variables were screened by correlation analysis to avoid affecting the prediction results due to overfitting of the model. The AUC value of the training set of the model ROC curve was above 0.8, and the prediction accuracy was high. The prediction results showed that the only nature reserve in Zhengzhou, Yellow River Wetland Nature Reserve, currently covers only 10.25% of the total area of the high suitability areas for plants and 17.54% of the high suitability habitat areas for waterfowl in the whole area of Zhengzhou. The potential suitability areas of wetland species outside the reserve can provide a basis for site selection for wetland conservation planning in Zhengzhou. It was found that the geographic distribution of wetland species in Zhengzhou is constrained by the distribution of water bodies, bioclimatic variables, land cover, and population density.

Database records of koalas (Phascolarctos cinereus) in northern Sydney

This study examined records of koalas (Phascolarctos cinereus) in northern Sydney held in online biodiversity databases. There were 221 unique records distributed across the Northern Beaches, Ku-ring-gai, Hornsby and Hills Shire local government areas from 1788 to 2022, with records from the Northern Beaches local government area comprising 68% of this dataset. Records from the 1970s represented 41% of the dataset (90 records), while there were only 42 records from 2000 to 2022. Post-2000 records were spread broadly, showing no major contraction in distribution compared to the spread of earlier records, but with a notable absence of more recent records on the Barrenjoey Peninsula, a previously documented species stronghold. Substantial proportions of records were found in both protected reserves and privately-owned lands, which alludes to the value of the former but also shows that koala conservation in this capital city cannot rely solely on protected reserves. The 2000–22 records were widely distributed across 15 plant community types and areas of non-native vegetation, probably reflecting breeding and dispersal movements more than specific habitat selection. Possibly due to the same influences, none of the 2000–22 records were matched to areas represented by the Koala Habitat Suitability Model, a prediction model for spatial distribution of potential koala habitat across NSW, with a high habitat suitability score (greater than 0.85). We therefore recommend systematic on-ground surveys to clarify the patterns observed from the records.

Does environmental adaptation or dispersal history explain the geographical distribution of Ixodes ricinus and Ixodes persulcatus ticks in Finland?

In Finland, the distribution area of the taiga tick, Ixodes persulcatus (Schulze, 1930), is nested within a broader area of distribution of a congeneric species, the sheep tick, Ixodes ricinus (Linnaeus, 1758) (Acari: Ixodidae). We assess whether distinct environmental adaptations or dispersal history provides a more parsimonious explanation for the differences in the distributions of the two common and medically important ixodids in Finland. We used an innovative spatially constrained randomization procedure to analyze whether crowdsourced occurrence data points of the two tick species had statistically different associations with any of the 28 environmental variables. Using points of presence in a region of species co-occurrence, we built Maxent models to examine whether environmental factors or dispersal history could explain the absence of I. persulcatus in a part of the range of I. ricinus in Finland. Five environmental variables-number of inhabitants, road length, elevation above sea level, proportion of barren bedrock and boulders, and proportion of unsorted glacial deposits-were significant at p ≤ .05, indicating greater between-species difference in original than in the randomized data. Of these variables, only the optimum value for unsorted glacial deposits was higher for I. persulcatus than for I. ricinus. Maxent models also predicted high relative habitat suitability (suitability >80%) for I. persulcatus south of its current, sharply bounded distribution range, suggesting that the species has not fulfilled its distribution potential in Finland. The two most common and medically relevant ixodids in Finland may colonize habitats with different environmental conditions. On the contrary, the recent establishment and ongoing dispersion of I. persulcatus in Fennoscandia rather than environmental conditions cause the southernmost distribution limit of the species in Finland.

Developing cost-effective monitoring protocols for track-surveys: An empirical assessment using a Canada lynx Lynx canadensis dataset spanning 16 years

Management agencies need statistically robust, cost-effective monitoring programs to effectively conserve and manage wildlife. However, this requires pilot studies to assess the monitoring protocol's ability to detect meaningful changes in the state variable of interest. This is more challenging for elusive mammals due to low detection rates and the costs associated with fieldwork. A key knowledge gap concerns how spatio-temporal dynamics in species occupancy and detection rates alter the cost-effectiveness of sampling protocols. To fill this gap we used a dataset spanning 16 years on Canada lynx (Lynx canadensis) track surveys conducted in Maine, USA, and developed optimal monitoring protocols that empirically assess the cost-effectiveness of these protocols under different scenarios. We surveyed 96 townships and detected 949 track intercepts, which were converted to detection histories under a spatially-replicated occupancy design. By combining occupancy modeling and power analyses, we estimated the sampling effort required to detect declines in occupancy from 10 to 50 %. Calculating the monetary cost of these protocols indicated that detecting subtle changes in occupancy (<10 %) is very expensive even within high suitability habitats and may often be unrealistic. However, protocols that detected medium (30 %) to large (50 %) declines required similar budgets and were consistent with the observed shifts in occupancy during our study period (34 %), suggesting that a modest budget increase would pay large dividends in population assessment efficacy. Our results provide important guidance on how to implement robust and cost-effective monitoring programs with snow track surveys – a popular survey method used by many conservation agencies.

Complex ecological and socioeconomic impacts on medicinal plant diversity.

Medicinal plant diversity (MPD) is an important component of plant diversity. Over-collection based on medicinal and economic value has the potential to damage the stability of the regional ecosystem. It is important to understand the current distribution of MPD and the factors influencing it. However, it is still unclear whether environmental and socioeconomic conditions have an impact on their distribution. We selected the Inner Mongolia as a representative study area which covers a wide area, accounting for 12.29% of China's national land area and 0.79% of the world's land area. At the same time, the region is a long-standing traditional medicinal area for Mongolians in China. Therefore, the region is significantly influenced by changes in environmental factors and socio-economic factors. We used 9-years field survey of the distribution of medicinal plants in Inner Mongolia for assessing the distribution of MPD as influenced by environmental and socioeconomic activities by combining spatial analyses, species distribution models, and generalized additive models. The results from the spatial analysis show that the western region of Inner Mongolia is the main cold spot area of the MPD, and the central-eastern and northeastern regions of Inner Mongolia are the main hot spot areas of the MPD. At the same time, the distribution of cold spots and hot spots of MPD is more obvious at large spatial scales, and with the refinement of spatial scales, the cold spots in scattered areas are gradually revealed, which is indicative for the conservation and development of MPD at different spatial scales. Under the future climate change of shared socioeconomic pathways (SSP), areas with high habitat suitability for medicinal plants remain mainly dominated by the Yellow River, Yin Mountains, and Greater Khingan Range. Notably, the SSP245 development pathway remains the most significant concern in either long- or short-term development. The nonlinear relationship between the driving factors of MPD at different spatial scales shows that temperature, precipitation and socioeconomic development do have complex effects on MPD. The presence of a certain temperature, altitude, and precipitation range has an optimal facilitation effect on MPD, rather than a single facilitation effect. This complex nonlinear correlation provides a reference for further studies on plant diversity and sustainable development and management. In this study, the spatial distribution of medicinal plant resources and the extent to which they are driven by ecological and socioeconomic factors were analyzed through a macroscopic approach. This provides a reference for larger-scale studies on the environmental and socioeconomic influences on the distribution of plant resources.

Potential habitat and carrying capacity of endangered San Joaquin kit foxes in an urban environment: implications for conservation and recovery

The San Joaquin kit fox (Vulpes macrotis mutica; SJKF) is federally endangered due to profound habitat loss. A population of SJKF occurs in the urban environment in the city of Bakersfield, California, and may be important for SJKF conservation. We conducted a systematic survey using automated camera stations and occupancy analysis to identify suitable habitat for SJKF in Bakersfield and to estimate a conceptual carrying capacity in the urban environment. We identified high, medium, and low suitability habitat totaling 121 km2, 196 km2, and 40 km2, respectively. Based on a mean urban kit fox home range size of 0.78 km2 and an assumption of two adults in high suitability home ranges and one adult in medium suitability ranges, we estimated the adult carrying capacity in Bakersfield to be 561 foxes. This estimate seems plausible as the number of adult SJKF in Bakersfield was estimated to be 381 in 2015, and the number of foxes already had been reduced by a sarcoptic mange epidemic that began two years earlier. A carrying capacity of 561 adults would increase the estimated range-wide carrying capacity by as much as 38%. Adult density estimates derived for the urban SJKF population based on the carrying capacity (1.57/km2) and home range size (2.56/km2) were higher than estimates for foxes in natural habitats. The urban SJKF population in Bakersfield is substantial and therefore could contribute significantly to conservation and recovery efforts for SJKF. Given our results, a potential conservation strategy may be to encourage or even establish additional urban SJKF populations.

The fungal pathogen Batrachochytrium salamandrivorans is not detected in wild and captive amphibians from Mexico.

The recent emergence of the pathogen Batrachochytrium salamandrivorans (Bsal) is associated with rapid population declines of salamanders in Europe and its arrival to new areas could cause dramatic negative effects on other amphibian populations and species. Amphibian species, present in areas with high amphibian diversity such as Mexico, could be highly threatened due to the arrival of Bsal, particularly salamander species which are more vulnerable to chytridiomycosis caused by this pathogen. Thus, immediate surveillance is needed as a strategy to efficiently contend with this emerging infectious disease. In this study, we analyzed 490 wild and captive amphibians from 48 species across 76 sites in the North, Central, and South of Mexico to evaluate the presence of Bsal. Amphibians were sampled in sites with variable degrees of amphibian richness and suitability for Bsal according to previous studies. From the 76 sampling sites, 10 of them were located in areas with high amphibian richness and potential moderate to high Bsal habitat suitability. We did not detect Bsal in any of the samples, and no signs of the disease were observed in any individual at the time of sampling. Our results suggest that Bsal has not yet arrived at the sampled sites or could be at low prevalence within populations with low occurrence probability. This is the first study that evaluates the presence of Bsal in different regions and amphibian species in Mexico, which is the second most diverse country in salamander species in the world. We highlight the risk and the importance of continuing surveillance of Bsal in Mexico and discuss control strategies to avoid the introduction and spread of Bsal in the country.

Prediction of Potential Habitats of Zanthoxylum armatum DC. and Their Changes under Climate Change

Climate change poses a severe threat to biodiversity. Greenhouse gas emissions have accelerated climate warming and significantly impacted species distribution and population dynamics. Zanthoxylum armatum DC. is an ecologically, medicinally, and economically important plant; it is cultivated as an economic crop at large scales in China, and is a valuable medicinal plant in India, Nepal, etc. A precise prediction of the potential distribution areas of Z. armatum will contribute to its protection and determination of its planting areas. In this paper, based on 433 distribution points and 19 climate factors, the MaxEnt model was used to analyze the spatial distribution pattern of Z. armatum between 1970 and 2000, predict its spatial distribution pattern in 2040–2060 (the 2050s) and 2081–2100 (the 2090s), and comprehensively assess the critical climate factors limiting its geographical distribution. The findings are as follows: (1) in the 1970–2000 scenario, the potential suitable distribution areas of Z. armatum include the subtropical monsoon climate regions of Japan, the Korean Peninsula, the south of the Qinling–Huaihe Line of China, and the regions along the southern foot of the Himalayas (India, Bhutan, Nepal, etc.), with an area of 330.54 × 104 km2; (2) the critical climate factors affecting the potential distribution of Z. armatum include temperature (mean diurnal temperature range, mean temperature of the coldest quarter, and temperature seasonality) and annual precipitation; (3) the distribution areas of Z. armatum will shift to higher latitudes and shrink under the three climate change scenarios in the 2050s and 2090s. In the 2090s–SSP585 scenario, the total area of suitable habitat will decrease most markedly, and the decrease rate of the highly suitable areas will reach up to 97.61%; only the region near Delong Town, Nanshan District, Chongqing City, will remain a highly suitable habitat, covering an area of merely 0.08 × 104 km2. These findings suggest that Z. armatum is susceptible to climate change. The border area between Guizhou Province and Chongqing City and the southwest district of Leshan City, Sichuan Province, will be a stable and moderately high potential suitable habitat for Z. armatum in the future. The above regions are recommended to be managed as key protected areas.

Influence of Pleistocene climate fluctuations on the demographic history and distribution of the critically endangered Chinese pangolin (Manis pentadactyla)

BackgroundPleistocene climate fluctuations have strongly modified species genetic diversity and distributions. The Chinese pangolin (Manis pentadactyla) has been recognized as a critically endangered animal due to heavy poaching and trafficking. However, the effect of Pleistocene climate fluctuations on the genetic diversity and spatial distribution of the Chinese pangolin remains largely unknown. Here, we combined whole genome sequencing data, analysis of complete mitochondrial genomes, and a large amount of occurrence data from field surveys to infer the ancestral demographic history and predict the past spatial dynamics of the Chinese pangolin in Guangdong Province, China.ResultsOur results indicated that there were two subpopulations, which showed similar trends of population size change in response to past climatic changes. We estimated a peak effective population size (Ne) during the last interglacial (LIG), followed by a marked decrease (~ 0.5 to fivefold change) until the last glacial maximum (LGM) and a rebound to a small peak population size during the Mid-Holocene (MH). The estimated time of the separation event between two subpopulations was approximately 3,000–2,500 years ago (ka). We estimated that the distribution of suitable areas shrank by 14.4% from the LIG to LGM, followed by an expansion of 31.4% from the LGM to MH and has been stable since then. In addition, we identified an elevational shift and suitable area decreased significantly during the LGM, but that the geographic extent of suitable areas in the western region increased from the LIG to present. The eastern region of Guangdong Province had the highest habitat suitability across all the climate scenarios.ConclusionsOur results suggested that Pleistocene climate fluctuations played an important role in shaping patterns of genetic diversity and spatial distribution, and that human stressors likely contributed to the recent divergence of two Chinese pangolin subpopulations sampled here. We argue that a key protected area should be established in the eastern region of Guangdong Province. As such, this study provides a more thorough understanding of the impacts of Pleistocene climate fluctuations impacts on a mammalian species in southern China and suggests more robust management and conservation plans for this Critically Endangered species of special interest.

Incorporating satellite remote sensing for improving potential habitat simulation of Prosopis cineraria (L.) Druce in United Arab Emirates

Predicting the suitable habitat of a species is one of the adequate and enhancing approach in biodiversity conservation planning and implementation. Species habitat distribution is closely linked with environmental factors and bioclimatic variables used as prediction variables in species distribution models (SDMs). Recent application of satellite remote sensing data and the bioclimatic variables has created an advanced way to improve the SDMs performance. In this study, MaxEnt was used to predict species habitat distribution. Our objectives are to assess the application of satellite remote sensing data in predicting the potential habitat suitability of the arid plant species. We have selected Prosopis cineraria (L.) Druce (Ghaf), the national tree of the UAE. We have chosen 33 environmental variables along with 90 species occurrences and for the final model simulation we have used three modeling scenarios. MaxEnt results showed that the model simulation with all key variables has substantially improved the potential habitat suitability prediction with a mean Area Under receiver operating Curve (AUC) value of 0.984, indicating a better predictive accuracy in the integration of satellite remote sensing data, edaphic variables and topographic parameters. Model results showed that the spatial proportions of the potential habitat suitability in the UAE consisted of high (2%), medium (6%) and low (9%) habitat suitability classes. The MaxEnt results revealed that precipitation of the coldest quarter (32.5%), NDVI (12.1%) and elevation (8%), had significant contribution to the potential habitat distribution of UAE Ghaf trees. Cold season precipitation is the most significant climate constraint on the habitat distribution. The most habitat suitability of Ghaf tree in the UAE was within a certain range of NDVI, LST, elevation, aspect, and precipitation patterns. This paper finding could be useful for environmental managers for implementing reforestation not only in UAE but also for the entire middle eastern regions with similar hyper arid conditions.