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Background Acmella radicans: (Jacquin) R.K. Jansen is a new invasive species record for Yunnan Province, China. Native to Central America, it has also been recently recorded invading other parts of Asia. To prevent this weed from becoming a serious issue, an assessment of its ecological impacts and potential distribution is needed. We predicted the potential distribution of A. radicans in China using the MaxEnt model and its ecological impacts on local plant communities and soil nutrients were explored. Results: Simulated training using model parameters produced an area under curve value of 0.974, providing a high degree of confidence in model predictions. Environmental variables with the greatest predictive power were precipitation of wettest month, isothermality, topsoil TEB (total exchangeable bases), and precipitation seasonality, with a cumulative contribution of more than 72.70% and a cumulative permutation importance of more than 69.20%. The predicted potential suitable area of A. radicans in China is concentrated in the southern region. Projected areas of A. radicans ranked as high and moderately suitable comprised 5425 and 26,338 km2, accounting for 0.06 and 0.27% of the Chinese mainland area, respectively. Over the 5 years of monitoring, the population density of A. radicans increased while at the same time the population density and importance values of most other plant species declined markedly. Community species richness, diversity, and evenness values significantly declined. Soil organic matter, total N, total P, available N, and available P concentrations decreased significantly with increasing plant cover of A. radicans, whereas pH, total K and available K increased. Conclusion: Our study was the first to show that A. radicans is predicted to expand its range in China and may profoundly affect plant communities, species diversity, and the soil environment. Early warning and monitoring of A. radicans must be pursued with greater vigilance in southern China to prevent its further spread. [ABSTRACT FROM AUTHOR]

Climate change significantly impacted on the survival, development, distribution, and abundance of living organisms. The Chinese serow Capricornis milneedwardsii, known as the "four unlike," is a Class II nationally protected species in China. In this study, we predicted the geographical suitability of C. milneedwardsii under current and future climatic conditions using MaxEnt. The model simulations resulted in area under the receiver operating characteristic curve (AUC) values above 0.9 for both current and future climate scenarios, indicating the excellent performance, high accuracy, and credibility of the MaxEnt model. The results also showed that annual precipitation (Bio12), slope, elevation, and mean temperature of wettest quarter (Bio8) were the key environmental variables affecting the distribution of C. milneedwardsii, with contributions of 31.2%, 26.4%, 11%, and 10.3%, respectively. The moderately and highly suitable habitats were mainly located in the moist area of China, with a total area of 34.56 × 104 and 16.61 × 104 km2, respectively. Under future climate change scenarios, the areas of suitability of C. milneedwardsii showed an increasing trend. The geometric center of the total suitable habitats of C. milneedwardsii would show the trend of northwest expansion and southeast contraction. These findings could provide a theoretical reference for the protection of C. milneedwardsii in the future. This study used the MaxEnt model to predict the current and future potential geographical distribution of Capricornis milneedwardsii, a vulnerable species endemic to China, under different climate change scenarios. Results suggest that the distribution of C. milneedwardsii is likely to expand in the future, with highly suitable areas increasing under both RCP 4.5 and RCP 8.5 scenarios. These findings could provide a theoretical reference for the protection of C. milneedwardsii in the future. [ABSTRACT FROM AUTHOR]

In recent years, the continuous expansion of Spartina alterniflora (S. alterniflora) has caused serious damage to coastal wetland ecosystem. Mapping the coverage of S. alterniflora by remote sensing and analyzing its growth pattern pose great importance in controlling the expansion and maintaining the biodiversity of coastal wetlands in Guangxi. This study aimed to use harmonic regression to fit time series data of vegetation indices based on Landsat images, and the phenological features were extracted as the input of random forest model to distinguish S. alterniflora in coastal zone of Guangxi from 2009 to 2020. The influence of natural environmental factors on the distribution of S. alterniflora was evaluated by Maxent model, and the potential distribution was analyzed. The results showed that: (1) Based on the time series data of characteristic indices fitted by harmonic regression, the extraction of phenological features of S. alterniflora identification effect exhibited high accuracy (in the result of 2009, Overall Accuracy [OA] = 97.33%, Kappa = 0.95). (2) During 2009–2020, the S. alterniflora in coastal zone of Guangxi kept proliferating and expanding from east to west. The total area of S. alterniflora continued to increase while the growth rate showed a trend that increased first and then decreased. (3) The Maxent model shows good accuracy in simulating the habitat of S. alterniflora, with a potential distribution area of 14,303.39 hm2. The findings will be beneficial to the understanding of dynamic changes of S. alterniflora in coastal zone of Guangxi and provide a scientific reference for other coastal wetland studies on S. alterniflora expansion. [ABSTRACT FROM AUTHOR]

Paleontological studies in the central Andes have uncovered the vulnerability of Polylepis forests to climate shifts, attributed to limited seed dispersal capabilities and the rugged terrain. Given the ecological significance of these forests‐forming species as biodiversity hotspots and carbon sinks, their restoration is imperative for the preservation of endemic species and ecosystem services. At the extreme south of the genus' range, we find Polylepis australis, a forest‐forming tree species endemic to Argentina and uniquely extending beyond the Andes into the Sierras Grandes of the Córdoba province. This study utilizes potential distribution models to help inform on restoration strategies considering projected future climate scenarios. Employing Maxent 3.4.3 with 453 presence locations, we estimated a present potential distribution spanning 13,923 km2. Our analysis of future climate projections reveals important poleward contractions alongside minor uphill shifts (20 m above sea level), ultimately resulting in a net habitat loss of 4596 km2 (34%). This underscores the critical role of climate simulations in identifying species specific priority sites for restoration efforts and also highlighting Polylepis forests susceptibility to both climate change and anthropogenic impacts. [ABSTRACT FROM AUTHOR]

The corrosion problem of the tank floor of the oil depot tank area becomes more and more serious with the extension of the operation time. At present, how to determine the potential distribution of the storage tank floor and how to judge the cathodic protection effect of the storage tank floor is the bottleneck of technological development. In this paper, by constructing a mathematical model of cathodic protection in the tank area, influence of deep well anode on potential distribution of tank bottom is calculated by boundary element method (BEM) with computer programming, to study the potential distribution of the tank floor under different anode parameters. The results show that the calculated results are in good agreement with the field measured results, which verifies the accuracy and reliability of the calculation. [ABSTRACT FROM AUTHOR]

With the advancement of global maritime transport, the carriage of foreign organisms by vessels is inciting ecological catastrophes such as red tides, posing a grave threat to China's marine environmental security. Clarifying the geographical distribution of invasive species and their relationship with climate change can provide scientific basis for their prevention and control. In this discourse, the study centers on the typical alien microalgae, Nitzschiella closterium. By integrating environmental variables and distribution data and employing an optimized Maxent model, we delve into its potential distribution in current and future ecological conditions in the coastal waters of China, as well as the response relationship to environmental variables. After model optimization, the results reveal that the Area Under the Curve (AUC) value of the training dataset for Nitzschiella closterium stands at 0.993, denoting a high degree of model accuracy and bestowing credibility upon the simulated outcomes. Currently, the high suitability area constitutes 0.74% of the total suitability area, with an area of 0.44×104 km², and is mainly distributed in the sea area corresponding to Jiangsu Province, Shanghai City, and Zhejiang Province. The most significant environmental factor affecting the geographical distribution of Nitzschiella closterium is the annual temperature variation range (bio24). In the context of future climate changes, there is an overall trend of substantial expansion in the high suitability area for Nitzschiella closterium, which is profoundly affected by climate change, suggesting that the future control will be more severe. This research comprehensively understands the response relationship of the invasive species Nitzschiella closterium to leading environmental variables and its potential geographical distribution in the context of climate change through macro prediction and proposes control countermeasures. It will provide a scientific basis for preventing and controlling Nitzschiella closterium invasions. [ABSTRACT FROM AUTHOR]

Biological invasions pose significant threats to biodiversity, with invasive species spread often facilitated by human activities. Consequently, this research utilized ecological niche modeling (ENM) to overcome this limitation and map the potential suitability of Microtheca ochroloma Stål, 1860 and Microtheca semilaevis Stål, 1860, which have been evaluated as potential insect pests in the Americas, zones for four genera of Brassicaceae, which include globally cultivated species such as Sinapis L., Raphanus L., Eruca Mill., and Brassica L. We utilized multiple methods to forecast the ecological habitat of Microtheca Stål, 1860 species based on distribution data and various environmental indicators. Our models, exhibiting high-performance metrics (TSS ranging from 0.84 to 0.96), revealed extensive environmental suitability for these species across the Americas, including previously unreported regions. The predicted zones overlapped significantly with areas where Brassicaceae crops were grown. Contrary to some previous assertions, our findings suggest that while these Microtheca species are recognized pests on these crops, their consistent widespread damage may be overstated. Nevertheless, their invasive potential could have broad ecological impacts, including biodiversity loss. Our research emphasizes the need for focused sampling in potential distribution zones and underlines the value of integrating ENM in predicting and managing invasive species spread. [ABSTRACT FROM AUTHOR]

The introduction of bees for agricultural production in distinct parts of the world and poor management have led to invasion processes that affect biodiversity, significantly impacting native species. Different Bombus species with invasive potential have been recorded spreading in different regions worldwide, generating ecological and economic losses. We applied environmental niche and potential distribution analyses to four species of the genus Bombus to evaluate the similarities and differences between their native and invaded ranges. We found that B. impatiens has an extended environmental niche, going from dry environmental conditions in the native range to warmer and wetter conditions in the invaded range. Bombus ruderatus also exhibited an extended environmental niche with drier and warmer conditions in the invaded range than in its native range. Bombus subterraneus expanded its environmental niche from cooler and wetter conditions in the native range to drier and warmer conditions in the invaded range. Finally, B. terrestris showed the most significant variation in the environmental niche, extending to areas with similar and different environmental conditions from its native range. The distribution models agreed with the known distributions for the four Bombus species, presenting geographic areas known to be occupied by each species in different regions worldwide. The niche analysis indicate shifts in the niches from the native to the invaded distribution area of the bee species. Still, niche similarities were observed in the areas of greatest suitability in the potential distribution for B. ruderatus, B. subterraneus, and B. terrestris, and to a lesser degree in the same areas with B. impatiens. These species require similar environmental conditions as in their native ranges to be established in their introduced ranges. Still, they can adapt to changes in temperature and humidity, allowing them to expand their ranges into new climatic conditions. [ABSTRACT FROM AUTHOR]

The introduction of bees for agricultural production in distinct parts of the world and poor management have led to invasion processes that affect biodiversity, significantly impacting native species. Different Bombus species with invasive potential have been recorded spreading in different regions worldwide, generating ecological and economic losses. We applied environmental niche and potential distribution analyses to four species of the genus Bombus to evaluate the similarities and differences between their native and invaded ranges. We found that B. impatiens has an extended environmental niche, going from dry environmental conditions in the native range to warmer and wetter conditions in the invaded range. Bombus ruderatus also exhibited an extended environmental niche with drier and warmer conditions in the invaded range than in its native range. Bombus subterraneus expanded its environmental niche from cooler and wetter conditions in the native range to drier and warmer conditions in the invaded range. Finally, B. terrestris showed the most significant variation in the environmental niche, extending to areas with similar and different environmental conditions from its native range. The distribution models agreed with the known distributions for the four Bombus species, presenting geographic areas known to be occupied by each species in different regions worldwide. The niche analysis indicate shifts in the niches from the native to the invaded distribution area of the bee species. Still, niche similarities were observed in the areas of greatest suitability in the potential distribution for B. ruderatus, B. subterraneus, and B. terrestris, and to a lesser degree in the same areas with B. impatiens. These species require similar environmental conditions as in their native ranges to be established in their introduced ranges. Still, they can adapt to changes in temperature and humidity, allowing them to expand their ranges into new climatic conditions. [ABSTRACT FROM AUTHOR]

Background: Anopheles stephensi is native to Southeast Asia and the Arabian Peninsula and has emerged as an effective and invasive malaria vector. Since invasion was reported in Djibouti in 2012, the global invasion range of An. stephensi has been expanding, and its high adaptability to the environment and the ongoing development of drug resistance have created new challenges for malaria control. Climate change is an important factor affecting the distribution and transfer of species, and understanding the distribution of An. stephensi is an important part of malaria control measures, including vector control. Methods: In this study, we collected existing distribution data for An. stephensi, and based on the SSP1-2.6 future climate data, we used the Biomod2 package in R Studio through the use of multiple different model methods such as maximum entropy models (MAXENT) and random forest (RF) in this study to map the predicted global An. stephensi climatically suitable areas. Results: According to the predictions of this study, some areas where there are no current records of An. stephensi, showed significant areas of climatically suitable for An. stephensi. In addition, the global climatically suitability areas for An. stephensi are expanding with global climate change, with some areas changing from unsuitable to suitable, suggesting a greater risk of invasion of An. stephensi in these areas, with the attendant possibility of a resurgence of malaria, as has been the case in Djibouti. Conclusions: This study provides evidence for the possible invasion and expansion of An. stephensi and serves as a reference for the optimization of targeted monitoring and control strategies for this malaria vector in potential invasion risk areas. [ABSTRACT FROM AUTHOR]

In recent decades, ecological niche models (ENMs) have been widely used to predict suitable habitats for species. However, for invasive organisms, the prediction accuracy is unclear. In this study, we employed the most widely used maximum entropy (MaxEnt) model and ensemble model (EM) Biomod2 and verified the practical effectiveness of the ENM in predicting the distribution areas of invasive insects based on the true occurrence of Hyphantria cunea in China. The results showed that when only limited data of invasive areas were used, the two ENMs could not effectively predict the distribution of suitable habitats of H. cunea, although the use of global data can greatly improve the prediction accuracy of ENMs. When analyzing the same data, Biomod2's prediction accuracy was significantly better than that of MaxEnt. For long‐term predictions, the area of suitable habitat predicted by the ENMs was much greater than the occurrence area; for short‐term predictions, the accuracy of the predicted area was significantly improved. Under the current conditions, the area of suitable habitat for H. cunea in China is 118 × 104 km2, of which 59.32% is moderately or highly suitable habitat. Future climate change could significantly increase the suitable habitat area of H. cunea in China, and the predicted area of suitable habitats in all climate scenarios exceeded 355 × 104 km2, accounting for 36.98% of the total land area in China. This study demonstrates the use of ENMs to study invasive insects and provides a reference for the management of H. cunea in China. [ABSTRACT FROM AUTHOR]

Wasmannia auropunctata, the little fire ant, is an invasive pest threatening native biodiversity, agricultural and forestry production, and public health. In January 2022, wild populations of W. auropunctata were reported for the first time on the Chinese mainland. However, the stage and degree of W. auropunctata invasion in China are unclear. Therefore, assessing the risk of establishment and the potential impacts associated with this pest is crucial for preventing further spread. This study used the Bayesian additive regression trees (BARTs) model and global occurrence records to assess the potential distribution of W. auropunctata in southern China and the associated risk of invading urban, rural, agricultural, and forest lands. The results from our models indicate that: (1) coastal areas, southwest, and central areas are particularly suitable for W. auropunctata establishment; (2) temperature, clay content, mean normalized differential vegetation index (NDVI), and urban area are important factors in the distribution of W. auropunctata; (3) the agricultural lands in the coastal areas and the Yunnan–Guangxi border, the urban and rural lands in the coastal areas, and grasslands in the southwest should prepare for possible W. auropunctata invasion; and (4) forest lands have the highest area at risk of W. auropunctata invasion in southern China. These results provide valuable information for planning and implementing the monitoring and control strategies against W. auropunctata invasion in China. [ABSTRACT FROM AUTHOR]

Bolson Tortoises (Gopherus flavomarginatus) are a keystone species whose burrows are a unique microhabitat for a large number of vertebrates in the Chihuahuan Desert. Through the construction of burrows, Bolson Tortoises modify the habitat, resulting in greater structural complexity. This in turn results in a greater number of niches and therefore in greater biodiversity, providing not only shelter from predators, adverse climatic conditions, and fires, but ideal conditions for reproduction, socialization and feeding of various species. The potential distribution of Bolson Tortoises, eight mammal, four bird, and seven reptile species that use Bolson Tortoise burrows was modeled for the present, as well as for 2050 and 2070. The maximum entropy model (Maxent) included 19 bioclimatic layers and altitude. The models suggest a decrease in the potential distribution of G. flavomarginatus (its distribution was reduced by 85.95% from the present scenario to 2070) and 17 out of the 19 species of vertebrates that use their burrows, in both projected scenarios. This indicates climate change would negatively affect not only species with restricted or micro-endemic distributions, such as Bolson Tortoises, but also those of wide distribution, such as Coyotes (Canis latrans), Striped Skunks (Mephitis mephitis), and Scaled Quail (Callipepla squamata). The models also indicate that the percentage of geographical overlap of ≥12 of vertebrate species with G. flavomarginatus will decrease drastically by 2070, thereby reducing the availability of microhabitat (G. flavomarginatus burrows) for these species. Reduced availability of microhabitats could affect the ability of these accompanying vertebrates to hide from predators or adverse weather conditions, as well as to find sites for reproduction or feeding (Lepus californicus, Athene cunicularia, M. mephitis, C. latrans, Lynx rufus, Vulpes macrotis, and M. mephitis). Our work emphasizes the importance of conservation actions to help Bolson Tortoises (G. flavomarginatus), which in turn will benefit other species of mammals, birds, and reptiles that require the presence of tortoise burrows as microhabitats. [ABSTRACT FROM AUTHOR]

The evolutionary dynamics of the ecoregions of southern South America and the species that inhabit them have been poorly studied, and few biogeographic hypotheses have been proposed and tested. Quaternary climatic oscillations are among the most important processes that have led to the current distribution of genetic variation in different regions of the world. In this work, we studied the evolutionary history and distribution of the Córdoba vesper mouse (Calomys venustus), a characteristic rodent of the region of which little is known about its natural history. Since the population dynamics of this species are influenced by climatic factors, this rodent is a suitable model to study the effects of Quaternary climatic oscillations in central Argentina. The mitochondrial cytochrome b gene was sequenced to analyze the phylogeography of C. venustus, and ecological niche modeling tools were used to map its potential distributions. The results of these approaches were combined to provide additional spatially explicit information about this species' past. Our results suggest that the Espinal was the area of origin of this species, which expanded demographically and spatially during the last glacial period. A close relationship was found between the Espinal and the Mountain Chaco. These results are consistent with previous studies and emphasize the role of the Espinal in the biogeographic history of southern South America as an area of origin of several species. [ABSTRACT FROM AUTHOR]

Simple Summary: Global warming has led to changes in species distribution patterns, and climate change directly impacts species' spatial and temporal distributions, disrupting Earth's ecological equilibrium. Haloxylon ammodendron is a typical desert shrub and plays a vital role in maintaining the structure and function of an arid desert ecosystem. In this study, the Maxent model was employed to predict potentially suitable areas for H. ammodendron in the 2030s, 2050s, and 2070s. We found that the suitable distribution area is expected to expand slightly under shared socioeconomic pathway scenarios in the future. Haloxylon ammodendron (H. ammodendron) is a second-class protected plant of national significance in China that is known for its growth in desert and semidesert regions, where it serves as a desert ecosystem guardian by playing a substantial role in maintaining ecosystem structure and function. The changing global climate has substantially altered the growth conditions for H. ammodendron. This study focuses on identifying the key variables influencing the distribution of H. ammodendron and determining their potential impact on future distribution. We employed the Maxent model to evaluate the current climate suitability for H. ammodendron distribution and to project its future changes across various shared socioeconomic pathway (SSP) scenarios. Our findings indicate that precipitation during the warmest quarter and precipitation during the wettest month are the most influential variables affecting the potentially suitable habitats of H. ammodendron. The highly suitable habitat area for H. ammodendron currently covers approximately 489,800 km2. The Maxent model forecasts an expansion of highly suitable H. ammodendron habitat under all future SSP scenarios, with the extent of unsuitable areas increasing with greater global warming. The increased highly suitable habitats range from 40% (SSP585) to 80% (SSP126) by the 2070s (2060–2080). Furthermore, our results indicate a continued expansion of desertification areas due to global warming, highlighting the significant role of H. ammodendron in maintaining desert ecosystem stability. This study offers valuable insights into biodiversity preservation and ecological protection in the context of future climate change scenarios. [ABSTRACT FROM AUTHOR]

In order to observe the habitats of the Anatolian banded newt (Ommatotriton nesterovi), field studies were carried out in a total of 11 different localities in Samsun, Zonguldak, Bartın, and Karabük provinces, and 12 ones in Trabzon and Rize provinces for the Caucasian banded newt (Ommatotriton ophryticus). MaxEnt modeling was performed in order to test the compatibility of the information obtained in field studies with the results obtained as a result of modeling. The coordinate data from of a total of 95 separate localities belonging to the O. nesterovi that exist in the literature and were obtained in this study, and 43 ones belonging to the O. ophryticus were used. When the data obtained from field observations and modeling in this study are evaluated together, it is understood that the Anatolian banded newt endemic to Türkiye chooses places with lower altitude and areas with lower slopes and forest that do not receive much direct sunlight takes an important place in the habitat preference of this species compared to the Caucasian banded newt distributed in Türkiye, Georgia, Russia, and Armenia. [ABSTRACT FROM AUTHOR]

The Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) originated in South America and is a major pest of the economically critical solanaceous crops. It is devastating to tomatoes, attacking mainly the leaves, stems, flowers and fruits of tomato plants, and can cause up to 100% damage. T. absoluta invaded China in 2017 and expanded rapidly, severely impacting the tomato industry. To illustrate the detailed potential distribution of T. absoluta in China, we used CLIMEX and MaxEnt models to predict the potential distribution of this pest using historical and future climate data. CLIMEX predicts a wider potential distribution area for T. absoluta in China than MaxEnt, which suggests that most of China is suitable for its distribution, except for the Tarim Basin in southern Xinjiang, western Inner Mongolia and northwestern Gansu. Both models accurately predicted the known distribution of T. absoluta in the provinces of Yunnan and Guangxi, and the predictions by both models suggest the total distribution range of T. absoluta in China is to increase slightly with future changes in climate temperature. These predictions will help understand the influence of climate change on the potential distribution of T. absoluta in China and thus provide a theoretical foundation for developing early monitoring, quarantine and control strategies. [ABSTRACT FROM AUTHOR]

Invasive insect species threaten the productivity of ecosystems worldwide, and ecological niche models can be used to predict distributions of invaders and guide management efforts. Ecological niche models can also aid monitoring for invasive species that are globally distributed. One such species is the yellow spotted stink bug (Erthesina fullo Thunberg), a polyphagous pest native to Asia that has established in Europe and South America and threatens specialty crops. Here, we used ecological niche models to predict the potential distribution of E. fullo, and created a website to display predictions. We show that E. fullo has peak occurrence probability in areas with annual mean temperatures around 20°C, and that the occurrence probability increases as maximum monthly temperature reaches up to 38°C. The likelihood of occurrence decreased as annual precipitation increased, but increased with greater precipitation in the wettest and driest months. This suggests E. fullo is most suited to regions that are warm and dry and where most precipitation occurs across only a few months, such as southern North America, central and southern South America, southern Europe, southern Africa, and central and eastern Australia. Given that E. fullo is a highly mobile hitchhiking insect that travels through cargo and other containers to new areas, the potential spread of this species into new regions should be carefully monitored. [ABSTRACT FROM AUTHOR]

Context: The Patagonian huemul, an endangered Odocoilinedeer, has an estimated 350–500 individuals remaining in Argentina. Today's population size, representing a numerical reduction of >99% of original estimates, is fragmented into small groups along ~2000 km of Andean mountains. The species' numbers were heavily reduced by past overexploitation and they disappeared in areas of high anthropogenic activity, predominantly the fertile valley bottoms. Aims: This research delineates the current potential distribution of Patagonian huemul by using climatic indicators, topographic and vegetational proxies, and anthropogenic pressure, to determine the relevance of the climatic envelope on current distribution. Methods: Occurrence records (latitude and longitude) were compiled (n = 159) by consulting the literature. Twenty environmental variables were used (WorldClim database) and two other representative environmental variables (normalised difference vegetation index (NDVI) and enhanced vegetation index (EVI)) were added to test their predictive power. We added the human footprint index (HFP) as a variable to control for model bias. Using the maximum entropy algorithm (MaxEnt), we modelled the species' potential distribution. We designated the historical distribution as area M. Additionally, we calculated three areas of distribution: current, historical and potential. Finally, we calculated distributional retraction of the species and area lost per year. Key results: The model showed good predictive power (AUCTest = 0.764 ± 0.091). However, low values were obtained for AUCtrain and AUCprom for the different predictor scenarios. Although the model shows the interaction among several climatic, environmental, and topographic variables, the human footprint index (39.9%) was the variable that most influenced the current potential distribution of this species. Conclusion: Our model shows that most of Patagonia's surface is climatically suitable for huemul. This suggests that the causes of distributional retraction are not related to limitations imposed by the climate envelope, but rather concur with recent research showing impact owing to the species' behavioural response to anthropogenic activity. Implications: Current populations are small, fragmented, and confined to poor-quality sites. Although the species is currently found mainly within protected areas, management actions must be initiated that promote innovative strategies in unprotected areas, as well as high-value habitats, particularly as protected areas contain limited fertile lower-valley habitats. Different anthropogenic factors heavily reduced the number of the huemul, an endangered Patagonian deer. Our aim was deliminated potencial distribution of huemul by using climatic indicators, topographic, vegetational, and anthropogenic. Our model shows that most of argentine Patagonia is climatically suitable for huemul, suggesting that the causes of the distributional retraction are linked to factors derived from the combination of characteristics of the species' biology and the increased anthropic. Therefore, it is necessary to conduct management and protection actions for species. [ABSTRACT FROM AUTHOR]

Armillaria altimontana is a fungus (Basidiomycota, Agaricomycetes, Agaricales, and Physalacriaceae) that is generally considered as a weak/opportunistic pathogen or saprophyte on many tree hosts. It widely occurs across the northwestern USA to southern British Columbia, Canada, but relatively little is known about its ecological role in the diverse forest ecosystems where it occurs. This review summarizes the biology and ecology of A. altimontana, including its identification, life cycle, distribution, host associations, and bioclimatic models under climate change. [ABSTRACT FROM AUTHOR]

Climate change has the potential to modify habitat characteristics and, consequently, induce species responses to ongoing environmental changes. Functional traits determine both if a species can persist and maintain stable population sizes in particular ecological conditions, and its capacity to disperse to more favourable habitats.Given that functional traits evolve over time, one could expect closely related species to show similar responses to climate change, which should identify vulnerable lineages. Alternatively, species‐specific functional traits may anticipate species responses to climate change, and therefore, trait composition should be a strong predictor.We compiled a comprehensive dataset of functional traits of 84 Iberian and Moroccan odonates species and built a phylogenetic tree to determine if dissimilarity of traits and phylogenetic relatedness are relevant to better discriminate species range‐shift responses to climate change.Modelling results for 66 species showed clear impacts of the increase in temperature and drought events on their potential distribution. The traits that best‐discriminated species that expanded their ranges were multivoltinism, short‐life cycles and preference for temporary habitats, whereas species with a reduced and displaced potential distribution were mostly semivoltine, with a short flying season, oviposition on gravel and restricted to permanent streams, small rivers or oligotrophic lakes. Trait conservatism was rejected and phylogenetic relatedness was a poor predictor of range shifts.Considering odonates as model organisms, traits such as voltinism, beginning and prolongation of flight period and preference of temporal habitats should be examined to anticipate range‐shift responses of freshwater insects to climate change. [ABSTRACT FROM AUTHOR]

The Sardinian grass snake, Natrix helvetica cetti, is an endangered endemic snake subspecies with a restricted and highly fragmented geographic distribution. Information on its ecology and detailed geographic distribution are scarce and may negatively impact on its conservation status. Therefore, a literature review on its taxonomy, morphology, ecology, and conservation is presented here. Moreover, field records from the authors, citizen science and the existing literature provide an updated geographic distribution highlighting its presence within 13 new and 7 historic 10 × 10 km cells. Bioclimatic niche modelling was then applied to explore patterns of habitat suitability and phenotypic variation within N. h. cetti. The geographic distribution of the species was found to be positively correlated with altitude and precipitation values, whereas temperature showed a negative correlation. Taken together, these outcomes may explain the snake's presence, particularly in eastern Sardinia. In addition, analysis of distribution overlap with the competing viperine snake (N. maura) and the urodeles as possible overlooked trophic resources (Speleomantes spp. and Euproctus platycephalus) showed overlaps of 66% and 79%, respectively. Finally, geographical or bioclimatic correlations did not explain phenotypic variation patterns observed in this highly polymorphic taxon. Perspectives on future research to investigate N. h. cetti's decline and support effective conservation measures are discussed. [ABSTRACT FROM AUTHOR]

Based on the distribution of Chuanminshen violaceum Sheh et Shan (C. violaceum) obtained from field investigation and literature, and the data of three future climate scenarios presented by CMIP6, a relationship model between potential distribution and environmental factors was established to analyze the key environmental factors affecting the distribution of C. violaceum in Sichuan, and to simulate and verify the distribution law and suitable range of C. violaceum in the background of climate change. The result showed that: the key environmental factors affecting the potential distribution of C. violaceum were annual precipitation, precipitation of the coldest quarter, the minimum temperature of the coldest month and temperature annual range. The thresholds for the moderately suitable and above regions were 874.0−1231.2mm, 22.1−83.9mm, −4.4−3.5℃ and 25.0−31.2℃. In the historical period (2000−2020) under the current climate scenario, the suitable regions of C. violaceum mainly concentrated in the bottom of Sichuan basin, the mountainous regions along the basin and the eastern of Panxi plateau, with a total area of 21.49×104 km2 . Compared with the historical period, the highly suitable areas of C. violaceum would decrease by 14.07% and 10.04% under SSP1−2.6 and SSP2−4.5 scenarios，while it would increase by 3.46% under SSP5−8.5 scenarios in the 2050s. The moderately suitable area of C. violaceum would increase by 27.36%, 10.94% and 30.66%. The highly suitable areas would decrease by 40.89%, 33.53% and 36.71% in the 2090s, while the moderately suitable area would increase by 4.85%, 20.05% and 8.9%. In order to cope with the adverse effects of climate change on the growth and development of C. violaceum in the future, the protection of wild germplasm resources of C. violaceum should be carried out based on the existing major producing areas, such as Chengdu, Bazhong, Guangyuan and Nanchong. At the same time, work such as seed selection, seedling breeding and good gene storage, should be carried out, also artificial cultivation should be vigorously promoted to develop characteristic industries and indirectly protect wild resources. [ABSTRACT FROM AUTHOR]

Mexican territory is one of the centers of origin and dispersion of the genus Opuntia, where several of its species have been an important plant resource for people in arid and semiarid zones. Opuntia streptacantha is widely distributed in Mexico; however, precise aspects of its geographic distribution and ecological status are still unknown. Here, we modeled its potential distribution under paleoclimatic, current, and future conditions through maximum entropy and predictions from 824 records and seven environmental variables. Potential distribution of O. streptacantha in the interglacial period was contracted and slightly north than current distribution, with 44,773 km2 of optimal habitat. In other past periods, the central location of potential distribution coincides with the actual current distribution, but the period of the last glacial maximum was characterized by 201 km2 of very suitable habitat, absent in interglacial, current, and future periods. The future model suggests that potential distribution will move toward the south of the Mexican territory. Synthesis and applications. The potential distribution of O. streptacantha can be applied for the conservation and management of the species, and also in the selection of areas with crassicaule scrubs for protection, conservation, and reproduction of species resistant to the hostile conditions of arid and semiarid zones of Mexican territory, where the structure and composition of the vegetation will be affected in the next 100 years. [ABSTRACT FROM AUTHOR]

Vanilla planifolia is a species of commercial importance. However, vanilla presents gene erosion problems due to its clonal reproduction. In the Huasteca of Hidalgo, there is no information on vanilla populations. Therefore, the objectives of this study were to identify the current populations and the potential distribution of, and the morphological variation in, the labellum of V. planifolia in the Huasteca of Hidalgo. Twenty-two accessions were located and selected. Based on 21 environmental variables, the niche modeling of the potential distribution was carried out with the MaxEnt program; with the Jackknife test being used to identify the variables that contributed to the model. Flowers from 22 accessions were collected and the labellum of each flower was dissected. Subsequently, 64 morphological variables were obtained and various multivariate analyses were performed. The results showed three regions, defined by the highest to the lowest probability that V. planifolia was distributed. The precipitation of the driest month, altitude, and vegetation cover delimited the distribution. Five different morphotypes were distinguished, and the main differences were associated with the middle part of the labellum as well as the entrance of pollinators to the flower; therefore, the characterization of the labellum showed an infraspecific variation in V. planifolia in populations of the Huasteca of Hidalgo. [ABSTRACT FROM AUTHOR]

To reveal the potential distribution characteristics of Phoebe zhennan in Guizhou Province and its response mode to environmental factors. Based on the geographical distribution points of P. zhennan in Guizhou Province, this study used MaxEnt and ArcGIS methods combining with 30 environmental factors such as climate, soil and topography to predict the potential habitat of P. zhennan in Guizhou Province and analyze the main environmental factors affecting the growth of P. zhennan. The results were as follows: (1) The AUC of MaxEnt model had an average value of 0.843, which indicated that it could well predict the geographical distribution of P. zhennan in Guizhou Province. The northeast of Guizhou Province was the key area of it’s potential habitat, with a decreasing trend from north to south and from east to west. The high suitable areas were mainly located in Tongren City, northeastern Guizhou Province and mid-eastern Zunyi City, northern Guizhou Province. The middle suitable and low suitable areas were concentrated in northern Tongren City, north-central Miao and Dong autonomous prefecture in southeastern Guizhou Province, Guiyang, northeastern Bijie City and northeastern Buyi and Miao autonomous prefecture in southern Guizhou Province. Other areas were not suitable for P. zhennan to grow. (2) The potential distribution area of P. zhennan in Guizhou Province was 80 013.47 km², which accounted for 45.4% of the whole province’s land area. The high suitable area covered 30 565.66 km², and the share of high suitable area was 17.4%. (3) Environmental factors including isothermality (Bio3), precipitation of the warmest quarte (Bio18), precipitation of the wettest month (Bio13), precipitation of the driest month (Bio14), min temperature of the coldest month (Bio6) and temperature seasonality (Bio4) were the main environmental factors affecting the potential distribution of P. zhennan in Guizhou Province. In conclusion, the results elucidate that the geographical distribution of P. zhennan in Guizhou Province and the main environmental factors affecting its distribution are of great significance. The results of this study will provide a scientific basis for seedling expansion, afforestation promotion, development and utilization of P. zhennan in Guizhou Province. [ABSTRACT FROM AUTHOR]

Abstract Modelling was carried out using maximum entropy model (MaxEnt) to explore and predict the invasion potential of littleseed canarygrass (Phalaris minor Retz.) in India under current as well as future climatic conditions under Representative Concentration Pathways (RCPs) 4.5 and 8.5 for the years 2050 and 2070. Mutually least correlated 8 bioclimatic variables along with soil and elevation data were used for the modelling over 223 occurrence locations of the species. Jackknife test revealed the significance of temperature derived variables viz. temperature seasonality, annual mean temperature and minimum temperature of the coldest month in governing the potential distribution of P. minor. Currently, 21% of India’s area is either highly (9%) or moderately (12%) suitable as habitat for P. minor. Our model predicts approximately 90% contraction in the area considered to be highly or moderately suitable climatically between 2050 and 2070 under both moderate and high emissions scenarios. Thus, under future climate, a significant niche shift by the species and decreased suitability was observed compared to the current distribution. The present study is first of its kind in exploring the invasion potential of alien invasive weed P. minor under climate change scenarios which is a current threat to rice-wheat system in Indo-Gangetic plains of India. [ABSTRACT FROM AUTHOR]

Land use change and global warming pose significant threats to biodiversity and affect species distribution throughout the planet. Both factors operate at different scales, so even spatial features that allow to evaluate these factors properly are relevant to the early identification of extinction risks, especially in highland ecosystems. This study aims to model the ecological niche of Polylepis incana Kunth and its future distribution areas based on bioclimatic variables in the Ecuadorian Andes, as to promote conservation strategies. By analyzing high-resolution climate data employing MaxEnt and QGIS software, the appropriate habitat for P. incana was modeled, and the main climatic variables that best predict its potential distribution were identified. In addition, by employing herbal data we evaluated the status of the species in the predicted habitats and related them to species distribution models. The results show that the suitable habitat for P. incana is ~11393 km² along the Ecuadorian Andes; out of the total area, 84009.90 ha correspond to the optimal site's category. The two most influential variables contributed 91.70% to the model. Also, 5.53% of the total area --distributed among 9 protected areas in the Eastern and Western mountain range-- was optimal to host this species. Furthermore, it is determined that, for the normal development of the species in relation to bioclimatic variables, the threshold ranges from 4.2 to 10.40 °C and from 138 to 332 mm of precipitation, with high nitrogen re-translocation values in the soil. This study provides valuable information that will undoubtedly help Ecuadorian local populations, authorities and researchers to generate highland-ecosystem conservation actions as a climate change combat mechanism. [ABSTRACT FROM AUTHOR]

Simple Summary: Based on the occurrence records and bioclimatic variables, the MaxEnt model was used to predict the potential geographical distribution of Heteronychus arator, Oryctes boas and Amphimallon majale worldwide, and we also discuss the possible distribution of Popillia japonica, Heteronychus arator, Oryctes monoceros, Oryctes boas and Amphimallon majale. The results showed that every continent has potential distribution areas for these species. In China, the potential distribution of Popillia japonica and Amphimallon majale was mainly concentrated in central eastern regions, while the presence of Heteronychus arator and Oryctes boas was mainly concentrated in the southwest areas. Oryctes monoceros has no possible distribution at present. Based on the predicted results, we recommend that the government carry out species monitoring to minimize financial losses. A hot topic in recent years is the prediction of the potential distribution of possible invasive insects. China is facing a great challenge due to invasive insects. Scarab beetles are a highly diverse group, and many of them are well-known invasive insects. Here, in order to prevent the invasion of scarab beetles in China, we screened the invasive insects globally and obtained a preliminary database of quarantine or invasive scarab beetles. From the obtained database, we selected the top five species (Popillia japonica, Heteronychus arator, Oryctes monoceros, Oryctes boas and Amphimallon majale) to discuss and analyzed the potential distribution of three species that have not invaded China by using the MaxEnt model. The prediction results show that every continent has potential distribution areas for these species. Specifically within China, Popillia japonica and Amphimallon majale were mainly concentrated in east central regions and Heteronychus arator and Oryctes boas were mainly distributed in the southwest areas, while Oryctes monoceros has no suitable area. Notably, Yunnan, Hunan, Jiangxi and Zhejiang province had a high risk of invasion. In general, local agriculture, forestry and customs departments in China should pay more attention to monitoring for the prevention of infestation by invasive insects. [ABSTRACT FROM AUTHOR]

Simple Summary: The damage by Hippotiscus dorsalis (Hemiptera: Pentatomidae) has resulted in the substantial mortality of moso bamboo in South China. In this study, we survey the damage of H. dorsalis from 2005 to 2013 in Huzhou, Zhejiang Province, and evaluate the current and future potential distribution in China. The results revealed (1) the April mean temperature and April maximum temperature were the main factors affecting the damage of H. dorsalis, and (2) the significant expansion of high suitable areas in Anhui and Jiangxi Provinces under future climate circumstances. Hippotiscus dorsalis is the main pest of Phyllostachys edulis in South China. The relationship between climate change and outbreak of H. dorsalis, and the current and future distribution of H. dorsalis are unknown. This study aimed to confirm the effect of climate on population density and the attacked bamboo rate of H. dorsalis, using field survey data from 2005 to 2013 in Huzhou, Zhejiang Province, and to reveal the potential distribution of H. dorsalis under current and future climate conditions using the MaxEnt model. The damage investigation and distribution forecast revealed the following: (1) The mean monthly temperature and maximum temperatures were main factors affecting the population density and the attacked bamboo rate in April in the Anji county of Zhejiang Province; they are all significantly and positively correlated. (2) High suitable area will significantly expand in Anhui and Jiangxi Provinces under the future climate circumstances, and the total suitable area will present a decrease because of the precipitation restriction. The significant expansion of high suitable area in the Anhui and Jiangxi Provinces under future climate circumstances means that the affected provinces will face even greater challenges. These findings provide a theoretical basis for the early forecasting and monitoring of pest outbreaks. [ABSTRACT FROM AUTHOR]

Based on 186 distribution records of Pinus massoniana in China and 19 climate factors in the three periods from 1931 to 1960, 1961 to 1990 and 1991 to 2017, the MaxEnt model was used to study the climate factors that affected the distribution of Pinus massoniana in China in the past 90 years, the climatic conditions suitable for the growth and distribution of Pinus massoniana, and the distribution of Pinus massoniana in different periods, in order to provide decision-making support for the artificial forests in southern China to cope with climate change. The results showed that: (1) the main climate factors affecting the distribution of Pinus massoniana were precipitation of coldest quarter, precipitation of driest month, temperature annual range, temperature seasonality, annual precipitation and mean Hainan island on the south side was reduced to none, and the distribution boundary of the Leizhou peninsula was about 2° northward than that of the period from 1931 to 1960. (3) With the climate change in the past 90 years, the overall potential suitable area of Pinus massoniana has shifted to the east to the north, the scattered suitable areas on the original west and south sides have decreased, and the total area of suitable areas has shown a trend of first decreasing and then increasing, and the current suitable areas are mainly distributed in the south of the Qinling-Huaihe line, north of the Leizhou peninsula, and east of the Hengduan mountains. At present, the optimum areas of Pinus massoniana are concentrated in Guangxi province, Guangdong province, Fujian province, central and southern Guizhou province, western Chongqing municipality and eastern Sichuan province, which are the most suitable planting areas for Pinus massoniana plantations.temperature of driest quarter. (2) The total area of suitable area and the area of slight suitable area in the period from 1931 to 1960 were the largest, about 1848800km2 and 874500km2, respectively, the area of optimum area was the largest in the period from 1961 to 1990, about 527100km2, and in the period from 1991 to 2017, the northern boundary was shifted about 1° to the north compared with the period from 1931 to 1960, the suitable area of [ABSTRACT FROM AUTHOR]

The Mira River basin in Ecuador has a high biodiversity. However, the intensive land-use has led to landscape changes and generated alterations in the distribution of species. This study evaluates the spatial patterns of the forest landscape and its impacts on the distribution of Dipsas elegans (Boulenger, 1986). Landsat satellite images of 1991, 2000, and 2017 have been used and landscape metrics have been generated for the evaluation of the forested landscape. Additionally, the analysis of the potential distribution of D. elegans has been performed using the maximum entropy model (MaxEnt). The results show a decrease in the forest cover of 235.726,96 ha (10,28%) and an annual deforestation rate of 0,44%. In addition, the native forest displays fragmentation due to the increase in the number of patches (1.249-1.741) and its density (0,23-0,33), because of agriculture advance and deforestation. D. elegans is mainly distributed in the middle basin, which is composed of native forest and other coverage with an area of 104.747 ha (19,6%). Habitat loss with respect to the distribution model accounts for 33.859,33 ha (32,32%), which shows that the species is susceptible to patch size reduction, edge, effects and habitat solation that threaten the specie's presence. [ABSTRACT FROM AUTHOR]

Simple Summary: Obolodiplosis robiniae is an invasive species found across Eurasia. This species has now established itself as a common pest of black locust trees, with widespread infestations resulting in severe defoliation and substantial ecological and economic damage. Considering its biology and ecology, we applied a machine-learning algorithm based on the maximum entropy principle. The model's predictions are consistent with the known distribution of O. robiniae. The total potential suitable area is 10,896,309.16 km2. In the context of future climate warming, the suitable area will extend to high latitudes, whereas the area in the south will decrease slightly. Governments should be concerned about the potential spread of O. robiniae throughout Eurasia, and quarantine measures should be implemented as soon as possible to avoid astronomical maintenance costs later on. Obolodiplosis robiniae was discovered in Eurasia at the beginning of the 21st century. In this study, we explore the present and future (in the years 2050 and 2070) trends in the potential distribution of O. robiniae in Eurasia under diverse climate change scenarios based on a maximum entropy model. Our findings indicated that the current potential distribution area of O. robiniae is within the range of 21°34′ and 65°39′ N in the Eurasian continent. The primary factor controlling the distribution of O. robiniae is temperature. The highly and moderately suitable areas are mainly distributed in the semi-humid and semi-arid regions, which also happen to be the locations where the host black locust (Robinia pseudoacacia L.) grows at its fastest rate. The forecast of the potential distribution area of O. robiniae revealed that the species would benefit from global warming. The region suitable for the habitat of O. robiniae is characterized by a large-scale northward expansion trend and an increase in temperature. This information would help the forestry quarantine departments of Asian and European countries provide early warnings on the probable distribution areas of O. robiniae and provide a scientific basis for the prevention and control of O. robiniae spread and outbreaks. [ABSTRACT FROM AUTHOR]

Climate change is one of the most serious threats to the world's biodiversity. Reptiles with limited dispersal capacities, small geographic ranges, or specialised habitats are considered to be especially vulnerable. In this study, we applied the Maximum Entropy algorithm to predict the current and future suitable habitats of a range-restricted species group (Cyrtodactylus chauquangensis) in Vietnam. The models show that the current suitable habitat of C. chauquangensis species group mainly covers areas in Ninh Binh, Thanh Hoa, and a part of Nghe An provinces, Vietnam, covering approximately 83,521.53 km2. The models also indicate Karst Distance, Mean Diurnal Range, and Precipitation of Driest Month as the top three important variables in generating the potential distribution of C. chauquangensis species group. Additionally, we also assessed the impact of climate change on the future suitable habitat of the group under different scenarios. Under the scenario of climate change RCP 4.5, the potential distribution for the group is predicted to decrease significantly, with an average of 59.74% and 65.74% in 2050 and 2070, respectively. For RCP 8.5, the average loss area due to climate change is around 64.18% and 71.44% in 2050 and 2070, respectively. Based on our predictions, suitable habitats in Ninh Binh, Thanh Hoa, and Nghe An provinces could be potential refugia of the group under the impact of climate change. We strongly suggest that these areas be highly prioritised for in-situ conservation measures to safeguard species of the C. chauquangensis group in Vietnam. [ABSTRACT FROM AUTHOR]

The vicious invasive alien plant Amaranthus palmeri poses a serious threat to ecological security and food security due to its strong adaptability, competitiveness, and herbicide resistance. Predicting its potential habitats under current and future climate change is critical for monitoring and early warning. In this study, we used two sets of climate data, namely, WorldClim1.4 and RCPs (the historical climate data of WorldClim version 1.4 and future climate data of RCPs), WorldClim2.1 and SSPs (the historical climate data of WorldClim version 2.1 and future climate data of SSPs), to analyze the dominant environmental variables affecting the habitat suitability and predict the potential distribution of A. palmeri to climate change in China based on the MaxEnt model. The results show that (i) Temperature has a greater impact on the distribution of A. palmeri. The relative contributions of temperature‐related variables count to 70% or more, and the annual mean temperature (bio1) reached more than 40%. (ii) At present, the potentially suitable area is widely distributed in the central‐east and parts of southwest China, and the high suitable area is focused on the North China Plain. The potential suitable area predicted by WorldClim1.4 and WorldClim2.1 both accounts for about 31% of China's total land area. (iii) Future climate change will expand the suitable habitats to high latitudes and altitudes. The overall suitable area maximum increased to 44.93% under SSPs and 38.91% under RCPs. We conclude that climate change would increase the risk of A. palmeri expanding to high latitudes and altitudes, the results have practical implications for the effective long‐term management in response to the global warming of A. palmeri. [ABSTRACT FROM AUTHOR]

As an agricultural pest, the rice water weevil (RWW), Lissorhoptrus oryzophilus, poses a severe threat to agriculture in China. This study aimed to predict the suitable distribution of the RWW in China under current and future climatic conditions based on MaxEnt model with tuning parameters. The results showed that the dominant environmental variables that influenced the geographic distribution of RWW were temperature seasonality (Bio4), mean temperature of the coldest quarter (Bio11), precipitation seasonality (Bio15), and precipitation of the warmest quarter (Bio18). Under the current climatic conditions, the total suitable area of RWW in China was 391.0698 million hm2, accounting for 40.77% of China. These suitable areas were mainly located in eastern China, central China and southern China. There was considerable overlap between the suitable areas of RWW and rice cropping regions in China. Under future scenarios, the highly suitable areas for RWW would increase significantly. The centroid migration in the suitable areas of RWW showed a trend of moving eastward and northward. The results of this study can provide theory and data support for the monitoring, early warning and control of RWW. [ABSTRACT FROM AUTHOR]

MaxEnt exhibits good stability; even if the distribution data information and environmental variables of the distribution area are incomplete, the potential distribution area of the species can be accurately predicted [[5], [7]]. A species distribution methodology uses algorithms to link the known distribution point data of the target species to related environmental variables, constructs a model to determine the ecological requirements required for species distribution, and projects the results of the operation to predict the potential distribution of species in a specific period and region in the future [[2]]. Potential Distribution of W. auropunctata in China The potential suitable distribution area of I W. auropunctata i obtained from MaxEnt is shown in Figure 5. [Extracted from the article]

Purpose: The corrosion problem of the tank bottom plate is growing more and more obvious as the usage period of the tank increases. The purpose of this study is to explore the specific effects of various factors on the potential distribution of the tank bottom plate and propose reasonable cathodic protection measures for tanks through simulation and indoor tests. Design/methodology/approach: In this paper, several aspects (such as anode conditions, soil resistivity and so on) impacting the potential distribution of the tank bottom plate are explored by means of indoor tests and MATLAB software simulations, and the related results are presented using Origin software plots. Findings: The results show that the potential value of the tank bottom plate is positively shifted with the increase of anode well depth and distance and the decrease of output current, and the overall potential distribution uniformity is higher; the anodic well output current has the greatest influence on potential distribution; to set up regional cathodic protection in the multitank area, the anodic well should be arranged in the central position between multiple tanks. Regional cathodic protection potential distribution for multiple anodes is more uniform, but a reasonable number of anodes should be selected, usually 2–3 anodes. Originality/value: This paper provides solid theoretical and technical support for the future establishment of cathodic protection systems in station yards, as well as the renewal and transformation of cathodic protection systems in old tanks, by investigating the influencing factors on the potential distribution of tank bottom plate and verifying them through indoor experiments. [ABSTRACT FROM AUTHOR]

Tropical montane cloud forest is one of the most threatened ecosystems, in central Veracruz, Mexico. Within this ecosystem, terrestrial orchids are strongly dependent on forest conditions and may be sensitive to environmental change. We applied field surveys of abiotic and biotic factors associated with the presence of the terrestrial orchid Cyclopogon luteo‐albus and combined this with correlative niche modeling approaches to evaluate its potential distribution under two different environmental sets and two different extents. Layers of environmental information were obtained from Landsat imagery and interpolated bioclimatic and soil property layers. Existing species records were used as training data by sampling five forest fragments in central Veracruz, utilizing herbarium and global biodiversity information facility databases. The resulting predictions were tested by sampling at 15 sites of potential distribution. The model predicted the presence of C. luteo‐albus with a reliability of 80%. The most important variables of models derived from interpolated layers coincide with site‐relevant parameters suggesting the utility of these tools to further explore species suitabilities at larger geographic extents. Potential distribution mapping is an important tool to identify key areas for conservation and priority areas for future studies of species and partially resolves the lack of records of many orchid species. [ABSTRACT FROM AUTHOR]

Prediction of species' potentially suitable distribution areas and their range shifts under future climate change has long been the focus of macroecology and biogeography. Gymnocypris chilianensis of Schizothoracinae and Triplophysa hsutschouensis of Triplophysa are isolated to the Shiyang, Heihe, and Shule Rivers of the Hexi River system, listed from east to west, along the northeastern part of the Qinghai–Tibetan Plateau (QTP). This spatial distribution provides a valuable set of conditions for investigating patterns of habitat suitability and potential impacts of accelerated plateau climate change on endemic plateau fish species. Here, we employed the maximum entropy (MaxEnt) model to first evaluate potentially suitable habitats of the two species and identify the primary impact factors under the current climate based on occurrence records and environmental variables; then, we predicted changes in suitable habitat areas and distribution centers under two representative concentration pathways (RCPs), 2.6 and 8.5, for the future (2050 and 2070). The results showed that annual precipitation and altitude were the two most important environmental factors predicting the suitable habitat of G. chilianensis and T. hsutschouensis. The areas of suitable habitat for G. chilianensis and T. hsutschouensis experienced a sequential westward decrease from the Shiyang River towards the Heihe and Shule Rivers under the current climate conditions. Under future climate changes, the areas of the potential geographical distribution of G. chilianensis and T. hsutschouensis were concentrated eastward towards the Shiyang River, the area of the species' ancestral origins. Suitable habitat centers of the two species shifted eastward from the Heihe River to the Shiyang River and higher altitude areas. Additionally, G. chilianensis showed a greater reduction in suitable habitat and greater eastward range shift compared to T. hsutschouensis. These findings provide empirical evidence that accelerated climate change on the QTP has severe consequences for endemic populations with restricted and isolated habitats. This study demonstrates that different plateau fish have similarities and differences in their responses to climate change. Our findings also highlight that the effects of climate change must be incorporated into the integrated conservation plans for fish species on the QTP and its adjacent areas. [ABSTRACT FROM AUTHOR]

Potential reconstruction is a powerful strategy for deriving accurate (sometimes called "exact") embedding potentials in the context of density-dependent embedding methods. It is particularly useful for partitioning covalent bonds in such fragment-based electronic-structure methods. While the general approach is well defined and easily explained, there are a number of choices to be made in practice, concerning, e.g., the specific reconstruction algorithm, the assignment of electrons to subsystems, or the initial guess potential. A general choice to be made is whether "exact" embedding potentials shall be derived for pre-defined target densities (top-down) or for approximate fragment densities that can be iteratively defined (bottom-up). Here, we compare the pros and cons of a variety of different variants of potential reconstruction, both in terms of conceptual issues and concerning their accuracy and efficiency. We also present several algorithmic improvements that can be crucial in critical cases of potential reconstruction, namely, we show (i) that a combination of basis-set and grid-based potential reconstruction schemes can lead to improved resulting densities, (ii) that similarly the combination of real-space and matrix-representation based potential reconstruction gives great advantages, and (iii) that the potential-matrix reconstruction by Zhang and Carter [J. Chem. Phys. 148, 034105 (2018)] can be made much more efficient by avoiding an explicit Hessian calculation. Additionally, we demonstrated (iv) that a double reconstruction, meaning a reconstruction of both the supersystem potential and the subsystem potential, may lead to beneficial error cancellation. We also address the question of consistent energetics derived from such reconstructed potentials. [ABSTRACT FROM AUTHOR]

Land conversion has influenced the distribution and movement of Asian elephants. This study was conducted to understand the ranging behaviour and habitat use of Asian elephants in Sungai Betis Forest Reserve (SBFR) in Gua Musang, Kelantan, Malaysia. ArcGIS and MaxEnt softwares were used to estimate the home range and potential distribution based on the occurrence data points and environmental variables, such as distance to water and road, elevation, slope and vegetation cover. The results obtained showed that home ranges of the elephants were concentrated in the fragmented forest. There was a strong correlation between the environmental variables, which play significant roles in influencing the ranging behaviour and habitat use of Asian elephants. [ABSTRACT FROM AUTHOR]

Due to the impact of future greenhouse effect on insect development, climate change will have a significant impact on the distribution patterns of pests. The Pseudococcus comstocki and the Ceroplastes japonicus are one of the serious scale pests in China, they severely damage yield of fruit trees. In this study, based on the current and future climate conditions(2050 and 2070), a niche model was used to predict the distribution of potential suitable areas of Pseudococcus comstocki and Ceroplastes japonicus in China. The results showed that the high-suitability areas of Pseudococcus comstockiare were located in most areas of Hebei, Henan, and Hunan, and some parts of Shanxi, Shaanxi, Zhejiang, Fujian, Jiangxi, and Guangxi in current climate conditions. The high-suitability areas of Ceroplastes japonicus were located in most areas of Henan, Hunan, and Jiangxi, as well as a few areas in Shaanxi, Shanxi, Yunnan, Guangxi, Guangdong, Fujian, Hebei, Anhui, Inner Mongolia, and Shandong. Compared with the current climate, the high-suitability area of Pseudococcus comstocki in 2050 will gradually increase by 1.22% than ever; while the high-suitability area of Ceroplastes japonicus will gradually decrease by 1.85%. In 2070, the highsuitability area of Pseudococcus comstocki will gradually increase to 6.71×105 km² that is the maximum when RCP is 8.5; the high-suitability area of Ceroplastes japonicus will gradually reduce to 2.65×105 km² that is the minimum when RCP is 8.5. Based on the current and future climate, the potential distribution areas of the two scale insects, Pseudococcus comstocki and Ceroplastes japonicus were predicted, the integrated pest management was determined through the range of the potential distribution areas, and the pest control measures was further optimized. [ABSTRACT FROM AUTHOR]

Simple Summary: Wild populations of C. pictus and C. amherstiae have been decreasing due to habitat fragmentation and long-term uncontrolled poaching. To support the Chrysolophus spp.'s conservation, we simulated the potential distribution of the two species in China, calculated the patch fragmentation index of suitable habitats of Chrysolophus spp. in nature reserve areas and non-nature reserve areas, and analyzed the habitat status of C. pictus and C. amherstiae in China. Compared with the previous studies, their habitat areas have been reduced. In addition, most of the suitable habitats were not in nature reserves and were highly fragmented. We offer recommendations for the Chinese government to formulate conservation schemes for the Chrysolophus spp. population in the future. Over the past few years, the wild population of Chrysolophus spp. has decreased remarkably. Habitat fragmentation is a significant cause for this serious threat to the survival of Chrysolophus spp. population. In order to further understand the distribution of potentially suitable habitats of Chrysolophus spp., we used the maximum entropy model to predict the potentially suitable habitats of C. pictus and C. amherstiae in China based on the known distribution. According to the prediction results of the model, we calculated the landscape pattern index to compare the fragmentation of the two species' potential suitable habitats in nature reserves and non-nature reserves. The results showed that the potentially suitable habitat for Chrysolophus spp. only accounted for a small area of China. The suitable habitats for C. pictus were mainly in Sichuan, Shaanxi, Hubei, and other provinces, and the model predicts a total area of 359,053.06 km2. In addition, the suitable habitats for C. amherstiae were mainly distributed in the three-parallel-river area, with a potential total area of 215,569.83 km2. The model also showed that there was an overlap of suitable habitats between the two species in the western edge of the Sichuan Basin. Previously, hybrids of the two pheasants have already been found in this same overlapping area predicted by the model. The landscape pattern index showed that in the potentially suitable habitat for Chrysolophus spp., the fragmentation of non-nature reserve areas was higher than that of nature reserve areas. The results revealed the distribution of potentially suitable habitats for Chrysolophus spp. in China and highlighted that the suitable habitats in non-nature reserve areas were in urgent need of conservation, thereby providing a key reference for the conservation of the Chrysolophus spp. population in the future. [ABSTRACT FROM AUTHOR]

Understanding the potential habitat of Meconopsis, their species richness distribution patterns, and their influencing factors are critical for the conservation and rational exploitation of this valuable resource. In this study, we applied the MaxEnt model to predict their potential distribution, mapped the distribution pattern of species richness, and analyzed the variation of species richness along environmental gradients. Finally, we calculated the landscape fragmentation indices between the five subregions. Our results found that: (1) the medium- and high-suitable habitats of Meconopsis were mainly distributed in the central and eastern Himalaya, the Hengduan Mountains, and the southeast edge of the plateau platform, with suitable habitats ranged from 3200 m to 4300 m, whose most important factor is precipitation of the warmest quarter; (2) species richness showed a hump pattern along the environmental gradients except for longitude that showed an increasing trend, mainly concentrated in the south and southeast; and (3) the subregions are in the descending order of species richness: plateau platform, Hengduan Mountains, central, eastern, and western Himalaya; the highest and lowest degree of landscape fragmentation were in the western Himalaya and eastern Himalaya, respectively. Our study provides a theoretical background for the conservation and sustainable exploitation of Meconopsis in the wild. [ABSTRACT FROM AUTHOR]

Simple Summary: Leptocorisa (Hemiptera: Alydidae) species, which are pests to rice cultivation, have changed their habitats owing to climate change, suggesting the precautionary evaluation of the distribution of these pests. In this study, we targeted three major pests in Leptocorisa species (L. chinensis, L. acuta, and L. oratoria) and evaluated their potential distributions. Most of the recorded regions of the Leptocorisa species are consistent with the result of potential distributions predicted, and the model predicted that climate change would expand their habitats mostly under the effect of minimum temperature and precipitation varied by seasons. The potential distributions of three species were expected to cover major rice cultivation areas regardless of climate change, suggesting a necessity for establishing a sustainable control strategy for the pests. We targeted three major Leptocorisa species (L. chinensis, L. acuta, and L. oratoria) and evaluated their potential distributions using MaxEnt. The results showed that most Asian countries and northern Australia would be suitable for at least one of these pest species, and climate change will expand their habitat northward. All of the developed models were evaluated to be excellent with AUC, TSS, and OR10%. Most of the recorded regions of the Leptocorisa species are consistent with the result of potential distributions predicted in this study. The results confirmed that the minimum temperature of the coldest month mainly influences the three Leptocorisa species distributions. The potential distributions of the three species cover major rice cultivation areas regardless of climate change, suggesting that it would be necessary to establish a sustainable control strategy for the pests. [ABSTRACT FROM AUTHOR]

This work proposes an improved broadband equivalent circuit model of the winding system of an ultrahigh-voltage direct current (UHVDC) converter transformer and the validation experiment of the model conducted on a tapped transformer. The matrices of the inductance, capacitance, and resistance parameters in the improved model were all obtained by the finite element method according to the winding system structure of a UHVDC transformer. Then, the potential distributions along the windings under impulse voltages with different waveforms were studied in detail. Finally, the relationship between the potential gradient and waveforms was obtained. This work provides a convenient method to acquire the broadband electromagnetic transient characteristics of the winding systems within UHVDC converter transformers. [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) synthesis provides a promising approach to produce green fuels, while the low energy conversion efficiency limits its application due to photocarrier recombination. Photocarrier recombination can be inhibited by building potential gradients in the photoelectrode with heterojunctions. However, despite the achieved progress, only a small amount of photocarriers can be collected and take PEC reactions. One of the main reasons is that the potential gradient provided by heterojunctions is limited in the depletion region, while photocarrier recombination mainly occurrs in the charge diffusion region. To break through the limitation of band engineering technique, herein, polarized BaTiO3 nanoparticles are embedded in BiVO4 composite photoanode to modulate the inner potential distribution so that more photocarriers can be successfully collected. The results show that the energy conversion efficiency has been significantly improved, as evidenced by an improved PEC H2O2 production concentration of 836 µmol L–1 under simulated sunlight illumination, which is 2.6 times of pure BiVO4 in the same situation. This work demonstrates a feasible strategy to enhance photocarrier collection efficiency by modulating the inner potential distribution in photoelectrode with an embedded polarizer, which can significantly enhance the energy conversion efficiency without extra energy consumption. [ABSTRACT FROM AUTHOR]

Antarctic krill is the key species of ecological system in the Amundsen Sea. At present, the suitable distribution is unobtainable by scientific surveys or data from the fishery. In this paper, the maximum entropy algorithm (Maxent) was used to obtain the potential distribution of adult Antarctic krill in order to provide useful information and reasonable reference for the policy on protecting potential krill habitats around the Amundsen Sea. Occurrence points and 17 environmental variables were used to simulate the distributions. Results show that the high and moderate suitable habitats lie between 65°S and 72°S in the Amundsen Sea. The high suitable habitat accounts for 8.1% of the total area of the Amundsen Sea. The sea ice persistence (ICE), total phytoplankton (PHYC), and the minimum value of dissolved iron (Fe_min) are the three dominant contributors to the model. Results from the response curves show that Antarctic krill preferred habitats with ICE of 0.42–0.93, PHYC of 2.48–2.77 mmol/m3 and Fe_min of (7.10×10−5)−(9.45×10−5) mmol/m3. Positive trends existed in the PHYC of the high and moderate suitable habitat, and a positive trend existed in the Fe_min of moderate suitable habitat. However, the probability of presence of Antarctic krill will decrease if the increase of the PHYC and Fe_min continues. [ABSTRACT FROM AUTHOR]

Freshwater crabs (Decapoda: Pseudothelphusidae) are a group of key invertebrates in the montane ecosystems of Colombia; they participate in the recycling of organic matter, are intermediate links in the trophic chains, and are sensitive to anthropogenic disturbances. The few studies in the department of Caldas have focused on morphological and taxonomic aspects, whereas their ecology and natural history are poorly known. Currently, this family is represented in the department by six species. The objective of this study was to establish the patterns of potential distribution of Pseudothelphusidae and promote conservation areas in the western-central region of Colombia. The records from the Entomological Collection of the University of Caldas (CEBUC) and secondary information (metadata) of different bioecological aspects of the voucher specimens were consolidated. 91 georeferences were compiled and 37 new geo-records are reported for the department. Maps on information gaps and potential distribution models of the studied species were generated with the MaxEnt algorithm. A wide distribution was detected in the middle and lower zones in the Magdalena and Cauca rivers, and three convergence nodes were generated for the conservation of the freshwater crab species in Caldas and Colombia. [ABSTRACT FROM AUTHOR]