Predicting the potential geographic distribution of Bactrocera bryoniae and Bactrocera neohumeralis(Diptera: Tephritidae) in China using MaxEnt ecological niche modeling

Bactrocera bryoniae and Bactrocera neohumeralis are highly destructive and major biosecurity/quarantine pests of fruit and vegetable in the tropical and subtropical regions in the South Pacific and Australia.Although these pests have not established in China,precautions must be taken due to their highly destructive nature.Thus,we predicted the potential geographic distribution of B.bryoniae and B.neohumeralis across the world and in particular China by ecological niche modeling of the Maximum Entropy(Max Ent)model with the occurrence records of these two species.Bactrocera bryoniae and B.neohumeralis exhibit similar potential geographic distribution ranges across the world and in China,and each species was predicted to be able to distribute to over 20%of the globe.Globally,the potential geographic distribution ranges for these two fruit fly species included southern Asia,the central and the southeast coast of Africa,southern North America,northern and central South America,and Australia.While within China,most of the southern Yangtze River area was found suitable for these species.Notably,southern China was considered to have the highest risk of B.bryoniae and B.neohumeralis invasions.Our study identifies the regions at high risk for potential establishment of B.bryoniae and B.neohumeralis in the world and in particular China,and informs the development of inspection and biosecurity/quarantine measures to prevent and control their invasions.

Human Settlement Evaluation in Mountain Areas Based on Remote Sensing,GIS and Ecological Niche Modeling

The Qinghai-Tibet Plateau is the word＇s highest and largest plateau. Due to increasing demands for environment exploration and tourism, a large transitional area is required for altitude adaptation. Hehuang valley, which locates in the transition zone between the Loess Plateau and the Qinghai-Tibet Plateau, has convenient transportation and relatively low elevation. Our question is whether the geographic conditions here are appropriate for adapted stay before going into the Qinghai-Tibet Plateau. Therefore, in this study, we examined the potential use of ecological niche modeling （ENM） for mapping current and potential distribution patterns of human settlements. We chose the Maximum Entropy Method （Maxent）, an ENM which integrates climate, remote sensing and geographical data, to model distributions and assess land suitability for transition areas. After preprocessing and selection, the correlation between variables and spatial auto- correlation input data were removed and 106 occurrence points and 9 environmental layers were determined as the model inputs. The threshold- independent model performance was reasonable according to lO times model running, with the area under the curve （AUC） values being 0.917± 0.01, and 0.923±0.002 for test data. Cohen＇s kappa coefficient of model performance was 0.848. Results showed that 82.22% of the study extent was not suitable for human settlement. Of the remaining areas, highly suitable areas aceounted for 1.19%, moderately for 5.3% and marginally for 11.28%. These suitable areas totaled 418.79 km2, and 86.25% of the sample data was identified in the different gradient of suitable area.The decisive environmental factors were slope and two climate variables： mean diurnal temperature range and temperature seasonality. Our model showed a good performance in mapping and assessing human settlements. This study provides the first predicted potential habitat distribution map for human settlement in Ledu County, which could also help in land use management.

Evolution of biogeographic disjunction between eastern Asia and North America in Chamaecyparis:Insights from ecological niche models

The disjunct distribution of plants between eastern Asia(EA) and North America(NA) is one of the most well-known biogeographic patterns. However, the formation and historical process of this pattern have been long debated. Chamaecyparis is a good model to test previous hypotheses about the formation of this disjunct pattern as it contains six species disjunctly distributed in EA, western North America(WNA)and eastern North America(ENA). In this study, we applied ecological niche models to test the formation of the disjunct pattern of Chamaecyparis. The model calibrated with the EA species was able to predict the distribution of eastern NA species well, but not the western NA species. Furthermore, the eastern Asian species were shown to have higher niche overlap with the eastern North American species. The EA species were also shown to share more similar habitats with ENA species than with WNA species in the genus. Chamaecyparis species in WNA experienced a significant niche shift compared with congeneric species. Chamaecyparis had a low number of suitable regions in Europe and the middle and western NA during the Last Glacial Maximum(LGM) period, and became extinct in the former region whereas it retains residual distribution in the latter. The extirpations in western NA and Europe in response to the late Neogene and Quaternary climatic cooling and the more similar habitats between ENA and EA ultimately shaped the current intercontinental disjunct distribution of Chamaecyparis. Both current hypotheses may be also jointly applied to explain more eastern Asian and eastern North American disjunctions observed today.

Cryptosporidiosis threat under climate change in China:prediction and validation of habitat suitability and outbreak risk for human-derived Cryptosporidium based on ecological niche models

Background Cryptosporidiosis is a zoonotic intestinal infectious disease caused by Cryptosporidium spp.,and its transmission is highly influenced by climate factors.In the present study,the potential spatial distribution of Cryptosporidium in China was predicted based on ecological niche models for cryptosporidiosis epidemic risk warning and prevention and control.Methods The applicability of existing Cryptosporidium presence points in ENM analysis was investigated based on data from monitoring sites in 2011–2019.Cryptosporidium occurrence data for China and neighboring countries were extracted and used to construct the ENMs,namely Maxent,Bioclim,Domain,and Garp.Models were evaluated based on Receiver Operating Characteristic curve,Kappa,and True Skill Statistic coefficients.The best model was constructed using Cryptosporidium data and climate variables during 1986‒2010,and used to analyze the effects of climate factors on Cryptosporidium distribution.The climate variables for the period 2011‒2100 were projected to the simulation results to predict the ecological adaptability and potential distribution of Cryptosporidium in future in China.Results The Maxent model(AUC=0.95,maximum Kappa=0.91,maximum TSS=1.00)fit better than the other three models and was thus considered the best ENM for predicting Cryptosporidium habitat suitability.The major suitable habitats for human-derived Cryptosporidium in China were located in some high-population density areas,especially in the middle and lower reaches of the Yangtze River,the lower reaches of the Yellow River,and the Huai and the Pearl River Basins(cloglog value of habitat suitability>0.9).Under future climate change,non-suitable habitats for Cryptosporidium will shrink,while highly suitable habitats will expand significantly(χ^(2)=76.641,P<0.01;χ^(2)=86.836,P<0.01),and the main changes will likely be concentrated in the northeastern,southwestern,and northwestern regions.Conclusions The Maxent model is applicable in prediction of Cryptosporidium habitat suitability and can achieve excellent simulation results.These results suggest a current high risk of transmission and significant pressure for cryptosporidiosis prevention and control in China.Against a future climate change background,Cryptosporidium may gain more suitable habitats within China.Constructing a national surveillance network could facilitate further elucidation of the epidemiological trends and transmission patterns of cryptosporidiosis,and mitigate the associated epidemic and outbreak risks.

Visualizing Patterns of Genetic Landscapes and Species Distribution of Taxus wallichiana(Taxaceae),Based on GIS and Ecological Niche Models

The Chinese yew（Taxus wallichiana）,which is widely distributed in the Himalayas and in southern China,is now on the edge of extinction.In order to understand the evolutionary processes that control the current diversity within this species at the genetic and ecological levels,its genetic patterns and range dynamics must first be identified and mapped.This knowledge can then be applied in the development of an effective conservation strategy.Based on molecular data obtained from 48 populations of T.wallichiana,we used GIS-based interpolation approach for the explicit visualization of patterns of genetic divergence and diversity,and a number of potential evolutionary hotspots have been specifically identified within the genetic landscape maps.Within the maps of genetic divergence and diversity,five areas of high inter-population genetic divergence and six areas of high intra-population genetic diversity have been highlighted in a number of separate mountain regions,and these evolutionary hotspots should have the priority to be protected.Furthermore,four geographical barriers have been identified： the eastern Himalayas,the Yunnan Plateau,the Hengduan Mountains and the Taiwan Strait.According to ecological niche modeling（ENM）,the populations of T.wallichiana within the Sino-Himalayan Forest floristic subkingdom experienced westward expansion from the periods of Last Inter-glacial to Last Glacial Maximum（LGM）.Following the LGM,the distribution range overall became reduced and fragmented.These findings challenge the classic mode of contraction-expansion in response to the last glaciation.In conclusion,our findings suggest that the changes in geographical landscapes and climate that occurred during the Quaternary resulted in current genetic landscape patterns.

Genetic analysis and ecological niche modeling delimit species boundary of the Przewalski’s scorpion(Scorpiones: Buthidae) in arid Asian inland

Reliable delimitation of venomous scorpions is not only consequential to toxicological studies but also instructive to conservation and exploration of these important medical resources.In the present study,we delimited species boundary for the the Przewalski’s scorpion from arid northwest China through a combined approach employing phylogenetic analysis,ecological niche modeling and morphological comparison.Our results indicate that the Przewalski’s scorpion represent an independent taxonomic unit and should be recognized as full species rank,Mesobuthus przewalskii stat.nov.This species and the Chinese scorpion M.martensii represent the eastern members of the M.caucasicus species group which manifests a trans-Central Asia distribution across the Tianshan Mountains range.We also discussed the likely geographic barrier and climatic boundary that demarcate distributional range of the the Przewalski’s scorpion.

Modelling the probability of presence of Aedes aegypti and Aedes albopictus in Iran until 2070

Objective:To determine the suitable ecological habitats of Aedes(Ae.)aegypti and Ae.albopictus in Iran due to climate change by the 2070s.Methods:All data relating to the spatial distribution of Ae.aegypti and Ae.albopictus worldwide,which indicated the geographical coordinates of the collection sites of these mosquitoes,were extracted from online scientific websites and entered into an Excel file.The effect of climatic and environmental variables on these mosquitoes was evaluated using the MaxEnt model in the current and future climatic conditions in the 2030s,2050s,and 2070s.Results:The most suitable areas for the establishment of Ae.aegypti are located in the southern and northern coastal areas of Iran,based on the model outputs.The modelling result for suitable ecological niches of Ae.albopictus shows that in the current climatic conditions,the southern half of Iran from east to west,and parts of the northern coasts are prone to the presence of this species.In the future,some regions,such as Gilan and Golestan provinces,will have more potential to exist/establish Ae.albopictus.Also,according to the different climate change scenarios,suitable habitats for this species will gradually change to the northwest and west of the country.The temperature of the wettest season of the year(Bio8)and average annual temperature(Bio1)were the most effective factors in predicting the model for Ae.aegypti and Ae.albopictus,respectively.Conclusions:It is required to focus on entomological studies using different collection methods in the vulnerable areas of Iran.The future modelling results can also be used for long-term planning to prevent the entry and establishment of these invasive Aedes vectors in the country.

Elevation transition of aquatic insects closely matches a thermal feature in the Yungas of Northwestern Argentina

Temperature is a key factor that shapes the distribution of organisms.Having knowledge about how species respond to temperature is relevant to devise strategies for addressing the impacts of climate change.Aquatic insects are particularly vulnerable to climate change,yet there is still much to learn about their ecology and distribution.In the Yungas ecoregion of Northwestern Argentina,cold-and warm-adapted species of the orders Ephemeroptera,Plecoptera,and Trichoptera(EPT)are segregated by elevation.We modeled the ecological niche of South American EPT species in this region using available data and projected their potential distribution in geographic space.Species were grouped based on their ecogeographic similarity,and we analyzed their replacement pattern along elevation gradients,focusing on the ecotone where opposing thermal preferences converge.Along this interface,we identified critical points where the combined incidence of cold and warm assemblages maximizes,indicating a significant transition zone.We found that the Montane Cloud Forest holds the interface,with a particularly greater suitability at its lower boundary.The main axis of the interface runs in a N-S direction and falls between 14°C-16°C mean annual isotherms.The probability of a particular location within a basin being classified as part of the interface increases as Kira’s warmth index approaches a score around 150.Understanding the interface is critical for defining the thermal limits of species distribution and designing biomonitoring programs.Changes in the location of thermal constants related to mountainous ecotones may cause vertical displacement of aquatic insects and vegetation communities.We have recognized significant temperature thresholds that serve as indicators of suitability for the interface.As global warming is anticipated to shift these indicators,we suggest using them to monitor the imprints of climate change on mountain ecosystems.

Potential distributional shifts in North America of allelopathic invasive plant species under climate change models

Predictive studies play a crucial role in the study of biological invasions of terrestrial plants under possible climate change scenarios.Invasive species are recognized for their ability to modify soil microbial communities and influence ecosystem dynamics.Here,we focused on six species of allelopathic flowering plants-Ailanthus altissima,Casuarina equisetifolia,Centaurea stoebe ssp.micranthos,Dioscorea bulbifera,Lantana camara,and Schinus terebinthifolia-Xhat are invasive in North America and examined their potential to spread further during projected climate change.We used Species Distribution Models(SDMs)to predict future suitable areas for these species in North America under several proposed future climate models.ENMEval and Maxent were used to develop SDMs,estimate current distributions,and predict future areas of suitable climate for each species.Areas with the greatest predicted suitable climate in the future include the northeastern and the coastal northwestern regions of North America.Range size estimations demonstrate the possibility of extreme range loss for these invasives in the southeastern United States,while new areas may become suitable in the northeastern United States and southeastern Canada.These findings show an overall northward shift of suitable climate during the next few decades,given projected changes in temperature and precipitation.Our results can be utilized to analyze potential shifts in the distribution of these invasive species and may aid in the development of conservation and management plans to target and control dissemination in areas at higher risk for potential future invasion by these allelopathic species.

Additions of landscape metrics improve predictions of occurrence of species distribution models

Species distribution models are used to aid our understanding of the processes driving the spatial patterns of species’ habitats. This approach has received criticism, however, largely because it neglects landscape metrics. We examined the relative impacts of landscape predictors on the accuracy of habitat models by constructing distribution models at regional scales incorporating environmental variables (climate, topography, vegetation, and soil types) and secondary species occurrence data, and using them to predict the occurrence of 36 species in 15 forest fragments where we conducted rapid surveys. We then selected six landscape predictors at the landscape scale and ran general linear models of species presence/absence with either a single scale predictor (the probabilities of occurrence of the distribution models or landscape variables) or multiple scale predictors (distribution models + one landscape variable). Our results indicated that distribution models alone had poor predictive abilities but were improved when landscape predictors were added; the species responses were not, however, similar to the multiple scale predictors. Our study thus highlights the importance of considering landscape metrics to generate more accurate habitat suitability models.

Potential distribution and ecological dimensions of four species in the genus Physopelta(Hemiptera:Largidae)

Our knowledge of the identity and distribution of most species on earth is remarkably poor. Species in hotspots tend to be scarce within their range which increases their probability of extinction. In this study, we used ecological niche modeling （ENM） to estimate dimensions of realized niches of 4 species that are totally （Physopelta robusta St^l and Physopelta slanbuschii Fabricius） or partially （Physopelta cincticollis StS,1 and Physopelta quadriguttata Bergroth） distributed in the Indo-Myanmar and South Central China hotspot, and predicted additional sites where they might be found. Our findings suggest that the range of the 4 species could extend beyond their presently known distributions, which might be useful for future field surveys. Niche overlap was modeled between the 4 species, with R slanbuschii and R robusta showing more tolerance to temperature and P quadriguttata and P. slanbuschii more tolerance to precipitation. This study presents one more case study which highlights the ecological approach for taxonomic study in biodiversity conservation, especially of poorly, little known, and localized endemic species.

Analysis of genetic diversity and prediction of Larix species distribution in the Qinghai–Tibet Plateau,China

Larix resources in the Qinghai-Tibet Plateau have important ecological and economic values.However,the lack of genetic diversity background and related research hinders the development of conservation strategies.In this study,genetic diversity and distribution of fi ve Larix species were investigated.Using 19 polymorphic microsatellite markers to study 272 representative individuals from 13 populations,the results show low genetic diversity at the population level,with variation explained mainly by diff erentiation among populations.The Larix populations were classifi ed into two clades,one formed by eight populations,including three of the species in this study,L.kongboensis,L.speciosa,and L.potaninii var.australis.The other clade consists of fi ve populations,including the other two species in this study,L.griffi thii and L.himalaica.Genetic distance of the species was aff ected by geographical isolation and genetic diversity was mainly aff ected by altitude.The area suitable for Larix spp.decreased during the Last Glacial Maximum compared to the current distribution according to the niche model,but should increase in future climate scenarios(2050s),expanding westward along the Himalayas.These results provide an important scientifi c basis for the development of conservation strategies and further the sustainable utilization of Larix resources in the Qinghai-Tibet Plateau.

Choosing among correlative, mechanistic, and hybrid models of species’ niche and distribution

Different models are available to estimate species’niche and distribution.Mechanistic and correlative models have different underlying conceptual bases,thus generating different estimates of a species’niche and geographic extent.Hybrid models,which combining correlative and mechanistic approaches,are considered a promising strategy;however,no synthesis in the literature assessed their applicability for terrestrial vertebrates to allow best-choice model considering their strengths and trade-offs.Here,we provide a systematic review of studies that compared or integrated correlative and mechanistic models to estimate species’niche for terrestrial vertebrates under climate change.Our goal was to understand their conceptual,methodological,and performance differences,and the appli-cability of each approach.The studies we reviewed directly compared mechanistic and correlative predictions in terms of accuracy or estimated suitable area,however,without any quantitative analysis to support comparisons.Contrastingly,many studies suggest that instead of comparing approaches,mechanistic and correlative methods should be integrated(hybrid models).However,we stress that the best approach is highly context-dependent.In-deed,the quality and effectiveness of the prediction depends on the study’s objective,methodological design,and which type of species’niche and geographic distribution estimated are more appropriate to answer the study’s issue.

Mapping the habitat suitability of Ottelia species in Africa

Understanding the influence of environmental covariates on plant distribution is critical,especially for aquatic plant species.Climate change is likely to alter the distribution of aquatic species.However,knowledge of this change on the burden of aquatic macroorganisms is often fraught with difficulty.Ottelia,a model genus for studying the evolution of the aquatic family Hydrocharitaceae,is mainly distributed in slow-flowing creeks,rivers,or lakes throughout pantropical regions in the world.Due to recent rapid climate changes,natural Ottelia populations have declined significantly.By modeling the effects of climate change on the distribution of Ottelia species and assessing the degree of niche similarity,we sought to identify high suitability regions and help formulate conservation strategies.The models use known background points to determine how environmental covariates vary spatially and produce continental maps of the distribution of the Ottelia species in Africa.Additionally,we estimated the possible influences of the optimistic and extreme pessimistic representative concentration pathways scenarios RCP 4.5 and RCP 8.5 for the 2050s.Our results show that the distinct distribution patterns of studied Ottelia species were influenced by topography(elevation)and climate(e.g.,mean temperature of driest quarter,annual precipitation,and precipitation of the driest month).While there is a lack of accord in defining the limiting factors for the distribution of Ottelia species,it is clear that water-temperature conditions have promising effects when kept within optimal ranges.We also note that climate change will impact Ottelia by accelerating fragmentation and habitat loss.The assessment of niche overlap revealed that Ottelia cylindrica and O.verdickii had slightly more similar niches than the other Ottelia species.The present findings identify the need to enhance conservation efforts to safeguard natural Ottelia populations and provide a theoretical basis for the distribution of various Ottelia species in Africa.

Comparative multi-locus assessment of modern Asian newts(Cynops, Paramesotriton, and Pachytriton:Salamandridae) in southern China suggests a shared biogeographic history

Evolutionary biologists are always interested in deciphering the geographic context of diversification,therefore they introduced the concept of comparative phylogeography, which helps to identify common mechanisms that contribute to shared genetic structures among organisms from the same region.Here, we used multi-locus genetic data along with environmental data to investigate shared phylogeographic patterns among three Asianendemic newt genera, Cynops, Paramesotriton and Pachytriton, which occurred in montane/submontane streams or ponds in southern China. Our 222samples from 78 localities covered the entire range of the three genera and represented the largest dataset of this group to date. We reconstructed matrilineal genealogies from two protein-coding,mitochondrial genes, and gene network from two nuclear genes. We also estimated divergence times of major cladogenetic events and used occurrence data to evaluate niche difference and similarity between lineages. Our results revealed a common basal split in all three genera that corresponds to the separation of two geographic terrains of southern China.Those ancient divergence occurred during middle to late Miocene and likely correlate with paleoclimatic fluctuations caused by the uplift of the Qinghai-Xizang (Tibet) Plateau (QTP).Particularly,the strengthening and weakening of Asian summer monsoons during the Miocene may have profoundly impacted southern China and led to repeatedly vicariance in those newts.However,despite differences in realized niches between lineages,there is no evidence for divergence of fundamental niches.Preservation of old newt matriline lineages in mountains of southern China suggests that the region acts as both museums and cradles of speciation.Based on those results,we advocate a multi-pronged protection strategy for newts in the three genera.

A look into the past, present and future potential distributions of Talinopsis frutescens, a North American endemic lineage closely related to Cactaceae

Talinopsis frutescens(Anacampserotaceae,a family that is close related to Cactaceae)is a succulent species endemic to North America.The aim of this study was to explore,using Ecological Niche Modeling(ENM),changes in potential distribution ranges considering different climate scenarios:past conditions during the Last Inter Glacial(LIG)and the Last Glacial Maximum(LGM),the present and projections for 2070(RCP 2.6 to 8.5).A pattern of contraction is observed during the LIG,which agrees with other studies focused in species from arid environments.This pattern was followed by a migration towards the south during the LGM and a possible recent expansion to the north as is observed in the present scenario.All future projections show the same contraction and fragmentation patterns,resulting in three discontinuous areas:the northern part of the Chihuahuan Desert,the southern-central part of the Mexican Plateau,and the smallest one in the Tehuacán-Cuicatlán Valley.Our projections for future scenarios agree with other studies and support that global climate change tends to alter the current distribution of arid environment species.

Effects of climate changes on distribution of Eremanthus erythropappus and E.incanus(Asteraceae)in Brazil

Phylogeographic patterns of endemic species are critical keys to understand its adaptation to future climate change.Herein,based on chloroplast DNA,we analyzed the genetic diversity of two endemic and endangered tree species from the Brazilian savanna and Atlantic forest(Eremanthus erythropappus and Eremanthus incanus).We also applied the climate-based ecological niche modeling(ENM)to evaluate the impact of the Quaternary climate(last glacial maximum*21 kyr BP(thousand years before present)and Mid-Holocene*6 kyr BP)on the current haplotype distribution.Moreover,we modeled the potential effect of future climate change on the species distribution in 2070 for the most optimistic and pessimistic scenarios.One primer/enzyme combination(SFM/HinfI)revealed polymorphism with very low haplotype diversity,showing only three different haplotypes.The haplotype 1 has very low frequency and it was classified as the oldest,diverging from six mutations from the haplotypes 2 and 3.The E.erythropappus populations are structured and differ genetically according to the areas of occurrence.In general,the populations located in the north region are genetically different from those located in the center-south.No genetic structuring was observed for E.incanus.The ENM revealed a large distribution during the past and a severe decrease in geographic distribution of E.erythropappus and E.incanus from the LGM until present and predicts a drastic decline in suitable areas in the future.This reduction may homogenize the genetic diversity and compromise a relevant role of these species on infiltration of groundwater.

Distribution of Malpighia mexicana in Mexico and its implications for Barranca del Río Santiago

Wild plants represent relatively unexplored resource of high economic potential,especially as an alternative to developing new crops and,even more relevant,for improving existing crops and contributing to nutrition and health.The wild species M alpighia mexicana(manzanita)has a wide tradition of food,medicinal and ornamental use in Mexico.It is part of the American-origin group of tropical shrubs that produce edible red fruits,such as A cerola,which is considered the most important natural source of vitamin C in the world.Given the role played by M.mexicana in Mexico,and particularly in Barranca del Río Santiago(Santiago River Canyon),we modelled its potential distribution in both geographical areas.We used species'records from databases,local herbaria and records collected by the authors as well as climatic variables representing long term average,variability and extreme conditions of temperature and precipitation.To fit the models we used the modelling algorithm Maxent and selected an adequate configuration by testing a range of model complexity settings.The results indicate a clear species preference for warm-dry tropical forest,most extensively in the Balsas river depression and the central valleys of Oaxaca.The probability of the species presence in the western region was also high,although the probability was also high for smaller surface areas,such as the region of Santiago river canyons,which are covered by warm-dry tropical forests.

Potential distribution of a montane rodent (Cricetidae, Handleyomys chapmani) through time in Mexico: the importance of occurrence data

Ecological Niche Modeling uses the geographic coordinates of species presence records as the primary input to estimate potential geographic distributions.It is little known whether carrying out rigorous data pre-processing is necessary before building niche models to be transferred to different time period.Here we compared the current,past,and future potential distributions projected by niche models built from two different databases,an open-access database and a database compiled ad hoc,for Handleyomys chapmani,a rodent closely associated with montane cloud forests in Mexico.The models predicted different spatial patterns of climatic suitability for the three periods examined.Based on our current knowledge of cloud forest species in Mexico,the distributions predicted by the model built from the ad hoc database are more ecologically realistic than those obtained from the open-access database.The models built using the open-access database were particularly inaccurate at the limits of the geographic range,predicting larger,more diffuse distributions for the three periods.We conclude that pre-processing occurrence data is crucial for mountain species,as the number of localities and even minor inaccuracies in the geographic coordinates can translate into very different climatic conditions due to abrupt altitudinal changes.Finally,the predicted shifts in the potential distribution of H.chapmani over time indicate that this species is highly susceptible to climate change.

Spatial distribution and impacts of climate change on Milicia excelsa in Benin,West Africa

African teak(Milicia excelsa(Welw.)C.C.Berg)is an endangered multi-use species.Understanding the impact of climate change on the distribution of this species may improve the ability to anticipate or recognize its decline or expansion and to take appropriate conservation measures if necessary.Ecological niche modeling was projected in geographical space to study the current and future distribution of M.excelsa in Bénin.MaxEnt was used to estimate the potential geographic distribution of the species under two Representative Concentration Pathways(RCP).Miroc 5 summaries and two RCP 4.5 and RCP 8.5 scenarios were used as predictor variables for projections of the geographic potential of this species.The performance of the model was assessed by the area under the curve(AUC),true skill statistics(TSS)and partial receiver operating characteristics(Partial ROC).From the results,M.excelsa was more a secondary species in the Guinean climatic zone and part of the Sudanian-Guinean and Sudanian climatic zone.The projections show a signifi cant decrease in suitable habitats for the species from the two RCP scenarios.Only a part of the Guinean climatic zone remained suitable and few protected areas will conserve in situ M.excelsa.For the sustainable conservation of M.excelsa,it is essential to strengthen the protection of sacred forests located in the Guinean climatic zone.