Potential Habitat Suitability Research Articles

Predicting the potential suitable habitats of genus Nymphaea in India using MaxEnt modeling.

Modeling and mapping the distribution of suitable habitats of aquatic plants are critical for assessing the impact of factors like changing climate on species habitat range shifts, declines, and expansions. Nymphaea is an aquatic perennial herb considered valuable because of its ornamental, economic, medicinal, and ecological importance. In India, the geographical distribution of Nymphaea is diverse, and the suitable habitats of individual species are vulnerable to the changing climate and global warming effects. Despite its increased vulnerability, only a few limited conservation efforts in aquatic environments are being made to date. In several places, the distribution of Nymphaea has been impacted by both anthropogenic and climate-related disturbances. A comprehensive strategy will be needed to meet the socio-ecological challenge of Nymphaea conservation. In this study, we employed maximum entropy (MaxEnt) method to assess how climate change affects the distribution of Nymphaea suitable habitat. The occurrence records of Nymphaea were collected from primary surveys, Global Biodiversity Information Facility (GBIF), and published works. Bioclimatic variables obtained from the Coupled Model Intercomparison Project (CMIP6) were employed as predictor variables in distribution modeling. The projections were made using three SSPs (stringent mitigation scenarios) for the future period of 2050. Our results showed shifts in the suitability ranges of Nymphaea under different projection scenarios. The study provides information about the distribution of suitable habitats for Nymphaea in India, which may be helpful for ongoing efforts to conserve and manage the aquatic plants, particularly in areas that are losing suitable climate conditions.

Assessing distribution changes of selected native and alien invasive plant species under changing climatic conditions in Nyeri County, Kenya.

The role of climate change in enhancing bio-invasions in natural environments needs to be assessed to provide baseline information for effective species management and policy formulations. In this study, potential habitat suitability maps were generated through Ecological Niche Modeling for five problematic alien and native species in current and future climate simulations for the periods 2050s and 2070s under RCP2.6, RCP4.5, and RCP8.5 emission scenarios. Projected current binary suitability maps showed that 67%, 40%, 28%, 68%, and 54% of the total study area ~ 3318 Km2 is suitable for C. decapetala, L. camara, O. stricta, S. didymobotrya and S. campylacanthum species, respectively. Assuming unlimited species dispersal, two of these species, C. decapetala and S. didymobotrya, were observed to have consistent gradual increase in potential habitats and no habitat losses under the three RCPs by the end of the 2050 and 2070 future periods. The highest recorded relative potential habitat increase was observed for O. stricta at ~205% under RCP2.6 and ~223% under RCP8.5. Although L. camara and O. stricta were observed to have habitat losses, the losses will be very low as compared to that of S. campylacanthum. L. camara and O. stricta relative habitat losses were predicted to be between ~1% under RCP2.6 to ~4.5% under RCP8.5 by 2070 while that of S. campylacanthum was between ~50% under RCP2.6 to ~68% under RCP8.5 by the year 2070. From this study we conclude that the target study species are expected to remain a big threat to inhabited areas as well as biodiversity hotspot areas especially in the Mt. Kenya and the Aberdare forest and national park reserves under climate change. The information generated through this study can be used to inform policy on prioritizing management of these species and subsequent determination of their absolute distributions within the area.

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

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

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

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

Current and future predicted distributions of invasive toads (Anura: Bufonidae) and bullfrogs (Anura: Ranidae) on Sado Island

Island ecosystems are thought to be hotspots of biodiversity but are also susceptible to invasion by alien species. Sado Island in Japan is a habitat for endemic and rare species, such as the endemic Sado wrinkled frog. However, two alien frog species, Bufo japonicus formosus and Lithobates catesbeianus , which have been introduced to the island are threatening the biodiversity of the island and their distribution information is lacking. In this study, we conducted a distribution survey of B. japonicus and L. catesbeianus over Sado Island and predicted their current and future potential distributions using a species distribution model. We found that B. japonicus currently inhabits the southwestern part of the island near its introduction point and is in the process of expansion. Meanwhile, L. catesbeianus has a wider distribution range than B. japonicus and is almost expanding throughout most of its potential suitable habitat. We predict that, in the future, B. japonicus will expand their distribution to the southeastern part of the island. These findings show that it is necessary for B. japonicus to prevent their expansion into further area and L. catesbeianus to reduce the population, considering their distribution status.

Patterns of spatial distribution, diel activity and human-bear conflict of Ursus thibetanus in the Hindu Kush mountains, Pakistan

The Asiatic black bear ( Ursus thibetanus ) is an elusive mammal and its conservation is currently a challenge in Pakistan due to the negative interaction with human communities and habitat fragmentation. We investigated the distribution, activity pattern and human-bear conflict of the Asiatic black bear in the Hindu Kush, a major mountains system in Pakistan. Our study was conducted from October 2020 to December 2020 in the Bahrain Valley, placed in the southeastern area of the Hindu Kush. We firstly carried out a preliminary sign survey for the bear's presence and, then, we installed an infrared sensor camera traps in the potential suitable habitat for the bear, 23 locations for 152 trap nights, to monitor its activity. Furthermore, to understand human-bear conflict, a questionnaire survey was submitted to 107 local people living in the bear’s habitat. The Asiatic black bear was photographed in 12 camera stations with 60 different capture events. We obtained a trap success percent of 64.8% between 2,100 m - 2,400 m above the sea level while the total trap success calculated for the whole camera trapping survey of the bears was 39.5%. The bears showed a bimodal activity pattern with peaks just after sunset and during the night (88% of observations from 00:00 to 06:00 and 18:00 to 24:00). We observed that the female and male bears and their puppies were not hibernating in subzero temperatures until December. Local communities had concerns over livestock and crops losses in the area. Our findings showed once again that the Asiatic black bear urgently needs effective management plans to guarantee its conservation in Pakistan.

Assessing the suitable regions and the key factors for three Cd-accumulating plants (Sedum alfredii, Phytolacca americana, and Hylotelephium spectabile) in China using MaxEnt model

Phytoremediation is an effective way to remove metals from contaminated soil, and selecting remediation plants suitable for climate conditions is a prerequisite for effective phytoremediation. In this study, a MaxEnt model was applied to investigate the potential distribution and habitat suitability of three Cd-accumulating plants in China- Sedum alfredii, Phytolacca americana, and Hylotelephium spectabile and explore the key environmental factors that affect their habitat suitability. A total of 44 environmental parameters, including bioclimatic variables, altitude, and soil property parameters were used. The results showed that: (1) For S. alfredii, suitable areas account for 14.9 % of the area of China, which are mainly distributed in the middle and lower reaches of the Yangtze River. (2) The suitable areas of P. americana account for 22.7 % of China and are mainly located in the regions of the Qinling Mountains and the south of China. (3) While that for H. spectabile are mainly located in the regions of northeastern China and certain regions of central China, with suitable areas account for 8.3 % of the area of China. (4) The distribution of these three plants is significantly affected by precipitation; specifically, solar radiation is an influential factor for the distribution of S. alfredii and H. spectabile, and temperature limits the distribution of P. americana. The selection and agronomic management of hyperaccumulators for phytoremediation requires multifactor consideration (e.g., climate, soil conditions and planting patterns). The results can provide guidance for identifying suitable areas for planting these three accumulating plants, which could not only prevent the unscientific cultivation of them in unsuitable habitats but also enhance the efficiency of phytoremediation. Meanwhile, these findings are expected to contribute to agronomic management for improved phytoremediation effects in different Cd-contaminated regions of China.

Suitable Habitats of Chrysolophus spp. Need Urgent Protection from Habitat Fragmentation in China: Especially Suitable Habitats in Non-Nature Reserve Areas.

Simple SummaryWild 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.

Predicting the potential distribution of four endangered holoparasites and their primary hosts in China under climate change.

Climate change affects parasitic plants and their hosts on distributions. However, little is known about how parasites and their hosts shift in distribution, and niche overlap in response to global change remains unclear to date. Here, the potential distribution and habitat suitability of four endangered holoparasites and their primary hosts in northern China were predicted using MaxEnt based on occurrence records and bioclimatic variables. The results indicated that (1) Temperature annual range (Bio7) and Precipitation of driest quarter (Bio17) were identified as the common key climatic factors influencing distribution (percentage contribution > 10%) for Cynomorium songaricum vs. Nitraria sibirica (i.e., parasite vs. host); Temperature seasonality (Bio4) and Precipitation of driest month (Bio14) for Boschniakia rossica vs. Alnus mandshurica; Bio4 for Cistanche deserticola vs. Haloxylon ammodendron; Precipitation of warmest quarter (Bio18) for Cistanche mongolica vs. Tamarix ramosissima. Accordingly, different parasite-host pairs share to varying degree the common climatic factors. (2) Currently, these holoparasites had small suitable habitats (i.e., moderately and highly) (0.97–3.77%), with few highly suitable habitats (0.19–0.81%). Under future scenarios, their suitable habitats would change to some extent; their distribution shifts fell into two categories: growing type (Boschniakia rossica and Cistanche mongolica) and fluctuating type (Cynomorium songaricum and Cistanche deserticola). In contrast, the hosts’ current suitable habitats (1.42–13.43%) varied greatly, with highly restricted suitable habitats (0.18–1.00%). Under future scenarios, their suitable habitats presented different trends: growing type (Nitraria sibirica), declining type (Haloxylon ammodendron) and fluctuating type (the other hosts). (3) The niche overlaps between parasites and hosts differed significantly in the future, which can be grouped into two categories: growing type (Boschniakia rossica vs. Alnus mandshurica, Cistanche mongolica vs. Tamarix ramosissima), and fluctuating type (the others). Such niche overlap asynchronies may result in severe spatial limitations of parasites under future climate conditions. Our findings indicate that climate factors restricting parasites and hosts’ distributions, niche overlaps between them, together with parasitic species identity, may jointly influence the suitable habitats of parasitic plants. Therefore, it is necessary to take into account the threatened holoparasites themselves in conjunction with their suitable habitats and the parasite-host association when developing conservation planning in the future.

Ecological niche differentiation in the Anatolian rock lizards (Genus: Anatololacerta) (Reptilia: Lacertidae) of the Anatolian Peninsula and Aegean Islands

The genus Anatololacerta is distributed in the eastern Mediterranean region including Asia Minor and some east Aegean islands. Recent phylogenetic studies suggested that this genus displayed cryptic diversity and was divided into five species: A. anatolica, A. pelasgiana, A. ibrahimi, A. finikensis and A. danfordi. The ecological niche differentiations of these species have not been studied so far. Our aims for this study were to predict the potential suitable habitats for the species nested in genus Anatololacerta, and to examine the niche overlaps and differentiations via identity and background tests. The occurrence data were obtained from literature and our own field surveys. Occurrence records were rarefied and assessed in a 30 arc-second resolution layer, compatible with several bioclimatic and topographic variables. Species distribution analyses were performed using maximum entropy approach and pairwise niche comparisons were evaluated by identity and background tests. Our results demonstrated that the species delimitation among this genus was not only affected by geographic isolation but also that precipitation and temperature influenced the habitat suitability for these species. Predicted suitability usually well matched the actual species distributions. Moreover, the niche overlap (identity test) analyses verified that allopatric Anatololacerta species show clear ecological differentiations. However, a niche overlap between parapatric species A. pelasgiana and A. finikensis, was confirmed by identity and background tests. It has been suggested that these parapatric species could be more affected by microclimatological parameters than the others. The results of our study are in agreement with the latest phylogenetic study within this genus.

Assessing the current genetic structure of 21 remnant populations and predicting the impacts of climate change on the geographic distribution of Phoebe sheareri in southern China

Phoebe sheareri is a valuable tree species known as “Golden Nanmu” and is one of the most important protected tree species in China. However, natural populations are decreasing because of climate change and anthropogenic factors. To evaluate the genetic diversity and structure of remnant populations and the impacts of climate change on the distribution of potential suitable habitats, we conducted a field investigation and sampled 21 P. sheareri natural populations to evaluate their genetic diversity and structure using simple sequence repeat (SSR) molecular markers. Then, we predicted the distribution of suitable P. sheareri habitats across China under future scenarios (RCP 2.6 and RCP 8.5) and periods (2050 and 2070) using multivariate modeling methods—the MaxEnt model. The results showed a medium level of genetic diversity and low inbreeding in the 21 P. sheareri natural populations, and genetic differentiation among populations was significant, with 21.2 % genetic variation among populations. The remnant populations of P. sheareri were grouped into four genetic clusters based on genetic structure; five environmental variables involving four temperature variables and precipitation seasonality (Bio12) might determine the distribution of P. sheareri populations. In the future, the suitable habitats of P. sheareri are manifested as northward migration, and the highly suitable habitats are expected to increase. Our results highlight the importance of conservation units in situ, giving priority to populations with higher genetic diversity (e.g., TMS, FJS, and THY populations); sampling strategies for ex situ conservation, breeding and reforestation should consider climate change, especially Bio1 (annual mean temperature) and Bio12 (annual precipitation). Overall, this study may provide useful genetic information for strategies for the protection, management, and utilization of P. sheareri.

Morphological characterization and habitat suitability modeling of the goat population of Benin under climate change scenarios

BackgroundInsufficient knowledge of the genetic and phenotypic diversity in the local Beninese goat population combined with the lack of understanding of its adaptive capacity to ongoing environmental and societal changes hampers the development of strategies for better management and genetic improvement. The objective of this study was to establish the current geographical distribution of goats in Benin based on their morphology and model the potential habitat suitability of the three known main goat phenotypes (i.e., Djallonké goat or Type I, Sahelian goat or Type II, and their Crossbreeds or Type III) under climate change scenarios. Ten qualitative and 26 linear body measurements were taken on 2114 adult female goats sampled across the three vegetation zones of the country. Fifteen ratios were generated from the quantitative variables. The data were analyzed using generalized linear model procedures followed by multiple comparisons of least-squares means and multivariate analytical methods, including canonical discrimination analysis and hierarchical ascendant classification. Each goat was then assigned to one of the three aforementioned main goat phenotypes following its morphological characteristics and according to the a priori cluster membership defined in the previous step. The Maximum Entropy algorithm was used to model the current and future distribution of the three goat phenotypes under climate change scenario using the Representative Conservation Pathways 4.5 and 8.5.ResultsAll linear body measurements varied among vegetation zones. In the discriminant function analysis, 71% of the measured individuals were correctly classified in their vegetation zone of origin by seven measured variables and three ratios. The cluster procedure analysis revealed two groups of goats subdivided into the three main phenotypes. The modeling results showed that the currently highly favorable habitats were distributed in the South for Type I, in the North for Type II, and both South and North for Type III. However, under climate change scenarios, the favorable habitats for Type I decreased while those of Types II and III increased.ConclusionsThe results of this study confirm the spatial variation of the goat population in Benin. The habitat suitability model can be used to support decision-making toward better management of goat genetic diversity in Benin.

Potential Current and Future Distribution of the Long-Whiskered Owlet (Xenoglaux loweryi) in Amazonas and San Martin, NW Peru.

Simple SummaryThe long-whiskered owlet (Xenoglaux loweryi) is threatened by human activities and is currently listed as vulnerable by the IUCN. Here, we geo-referenced long-whiskered owlet records, identified key environmental variables affecting their distribution, and predicted their current and future distribution (2050 and 2070) in the Amazonas and San Martin areas of northwestern Peru. Under current conditions, areas with “high”, “moderate”, and “low” probability for the distribution of X. loweryi cover about 0.16% (140.85 km2), 0.46% (416.88 km2), and 1.16% (1048.79 km2) of the study area, respectively. Moreover, under future conditions, the “high”, “moderate”, and “low” probability areas showed profits and losses in terms of habitat suitability. Importantly, the natural protected areas in Amazonas and San Martin, both in current and in the future conditions, do not cover most of the pivotal habitats for X. loweryi. Furthermore, it was evident that the combination of climate change and anthropogenic activities will lead to further habitat loss for this species. Therefore, to effectively conserve this species over time, it is strongly recommended that areas with “high” (and even “moderate”) probability and the main ecosystems that this species inhabits be designated as priority areas for research and conservation (including in natural protected areas).The IUCN has listed the long-whiskered owlet (Xenoglaux loweryi) as vulnerable due to the presence of few geographic records, its restricted range, and anthropogenic threats. Its natural history and ecology are largely unknown, and its distribution is widely debated; therefore, there is an urgent need for the real-time conservation of X. loweryi. In this study, 66 geo-referenced records of X. loweryi, 18 environmental variables, and the maximum entropy model (MaxEnt) have been used to predict the current and future (2050 and 2070) potential distribution of X. loweryi in the Amazonas and San Martin regions of northwestern Peru. In fact, under current conditions, areas of “high”, “moderate”, and “low” potential habitat suitability cover 0.16% (140.85 km2), 0.46% (416.88 km2), and 1.16% (1048.79 km2) of the study area, respectively. Moreover, under future conditions, the “high”, “moderate”, and “low” probability areas present profits and losses in terms of habitat suitability. Based on the environmental variables, this species mostly inhabits areas with a forest fraction with presence of trees with an emergent tree canopy of ~10–30 metres and depends on Yunga montane forest habitats with high humidity but it is not dependent on bare cover area, crops, or grasslands. Nevertheless, most of the current and future distribution areas are not part of the protected natural areas of Amazonas and San Martin. Additionally, the combination of climate change and anthropogenic activities contribute to further losses of this species habitat. Therefore, from the management point of view, corrective and preventive actions will help to preserve this species over time.

Simulation of the potential distribution of rare and endangered Satyrium species in China under climate change.

Satyrium is an endangered and rare genus of plant that has various pharmacodynamic functions. In this study, optimized MaxEnt models were used in analyzing potential geographical distributions under current and future climatic conditions (the 2050s and 2070s) and dominant environmental variables influencing their geographic distribution. The results provided reference for implementation of long‐term conservation and management approaches for the species. The results showed that the area of the total suitable habitat for Satyrium ciliatum (S. ciliatum) in China is 32.51 × 104 km2, the total suitable habitat area for Satyrium nepalense (S. nepalense) in China is 61.76 × 104 km2, and the area of the total suitable habitat for Satyrium yunnanense (S. yunnanense) in China is 89.73 × 104 km2 under current climatic conditions. The potential suitable habitat of Satyrium is mainly distributed in Southwest China. The major environmental variables influencing the geographical distribution of S. ciliatum were isothermality (bio3), temperature seasonality (bio4), and mean temperature of coldest quarter (bio11). Environmental variables such as isothermality (bio3), temperature seasonality (bio4), and precipitation of coldest quarter (bio19) affected the geographical distribution of S. nepalense; and environmental variables such as isothermality (bio3), temperature seasonality (bio4), and lower temperature of coldest month (bio6) affected the geographical distribution of S. yunnanense. The distribution range of Satyrium was extended as global warming increased, showing emissions of greenhouse gases with lower concentration (SSP1‐2.6) and higher concentration (SSP5‐8.5). According to the study, the distribution of suitable habitat will shift with a change to higher elevation areas and higher latitude areas in the future.

Modelling potential habitat suitability for critically endangered Arabian leopards (Panthera pardus nimr) across their historical range in Saudi Arabia

Camera trapping can detect and monitor rare species in landscapes spanning thousands of square kilometres but placement of cameras in areas where the animals most likely occur will increase detection success. This vital information is lacking for the critically endangered Arabian leopard (Panthera pardus nimr) that has undergone a 90% decline across its range in Saudi Arabia. We aimed to identify suitable Arabian leopard habitat and potential population capacity in Saudi Arabia using data from leopards living in ecologically analogous habitat in South Africa and Oman. We developed a resource selection function (RSF) from 14 leopards’ GPS data in the Cederberg, South Africa, and validated the model using three leopards in the Little Karoo, and two Arabian leopards in Oman. We then projected the model to the historical range of Arabian leopards in Saudi Arabia to estimate likely leopard locations and potential population sizes based on home range metrics. The RSF successfully discriminated between used and available locations (specificity = 96.7%) and had high predictive ability (Rho > 0.9). Leopards selectively used areas away from human settlements and roads, with high enhanced vegetation index, and intermediate slopes and elevations. Saudi Arabia could theoretically host 4 distinct populations totalling 162–362 Arabian leopard females, depending on home range size. Camera traps deployed in the south-western mountains of Saudi Arabia may be most likely to detect remnant populations of Arabian leopards. Further research is needed into the local abundance of prey species and human activity to ensure the persistence of suitable leopard ranges and inform conservation actions.

A UAS and Machine Learning Classification Approach to Suitability Prediction of Expanding Natural Habitats for Endangered Flora Species

In this study, we propose integrating unmanned aerial systems (UASs) and machine learning classification for suitability prediction of expanding habitats for endangered flora species to prevent further extinction. Remote sensing imaging of the protected steppe-like grassland in Bilje using the DJI P4 Multispectral UAS ensured non-invasive data collection. A total of 129 individual flora units of five endangered flora species, including small pasque flower (Pulsatilla pratensis (L.) Miller ssp. nigricans (Störck) Zämelis), green-winged orchid (Orchis morio (L.)), Hungarian false leopardbane (Doronicum hungaricum Rchb.f.), bloody cranesbill (Geranium sanguineum (L.)) and Hungarian iris (Iris variegate (L.)) were detected and georeferenced. Habitat suitability in the projected area, designated for the expansion of the current area of steppe-like grassland in Bilje, was predicted using the binomial machine learning classification algorithm based on three groups of environmental abiotic criteria: vegetation, soil, and topography. Four machine learning classification methods were evaluated: random forest, XGBoost, neural network, and generalized linear model. The random forest method outperformed the other classification methods for all five flora species and achieved the highest receiver operating characteristic (ROC) values, ranging from 0.809 to 0.999. Soil compaction was the least favorable criterion for the habitat suitability of all five flora species, indicating the need to perform soil tillage operations to potentially enable the expansion of their coverage in the projected area. However, potential habitat suitability was detected for the critically endangered flora species of Hungarian false leopardbane, indicating its habitat-related potential for expanding and preventing further extinction. In addition to the current methods of predicting current coverage and population count of endangered species using UASs, the proposed method could serve as a basis for decision making in nature conservation and land management.

Predicting the Effects of Climate Change on the Suitable Habitat of Japanese Spanish Mackerel (Scomberomorus niphonius) Based on the Species Distribution Model

Japanese Spanish mackerel (Scomberomorus niphonius) is an important commercial fish species with a seasonal migratory habit in China. At present, no study has reported the seasonal variation of its potential suitable habitat. Therefore, we used biomod2 ensemble model to predict the potential suitable habitat of S. niphonius in different seasons through its current distribution sites and future environmental variables. Our results showed that the ensemble model had a high accuracy, with true skill statistics and receiver operator characteristic values of 0.91 and 0.98, respectively. Under the Representative Concentration Pathway (RCP) 4.5 scenario, the reduction rate of suitable habitats in summer of 2050 will be 33.2%, and those for the rest of the seasons will reach 3.5%. The reduction rate in summer of 2100 will be 43.5%, and those for the remaining seasons will reach 6.5%. In addition, this reduction rate will become more serious with the increase in emission scenario and time, especially in the RCP8.5 in which the summer reduction rate is as high as 88.9%. Habitat changes in summer show a strong temperature sensitivity. The distribution centroid of S. niphonius will shift to higher latitudes under RCP 4.5 and RCP 8.5. Depth and temperature are the two most important factors that affect the distribution of this species. The results can provide basic data for understanding the adaptability of S. niphonius to climate change and establishing an elastic ecosystem.

Fengshui forests as a conservation paradigm of the golden larch in China

Potential suitable habitats for relict species are facing critical reductions due to intensified anthropogenic disturbances and climate change. These facts not only pose new challenges, but also call for a paradigm shift for the effective conservation of relict plant species. We investigated in situ population structures and regeneration status under varying management scenarios for Pseudolarix amabilis, a relict conifer endemic to China. We also re-evaluated the conservation status of P. amabilis using our latest in situ population census data. We found that the conservation status of P. amabilis is more pessimistic than expected. Hence, wild P. amabilis populations urgently need to be considered for conservation. More concretely, intensive and frequent anthropogenic disturbances reduce population recruitment, but a reduced population recruitment also occurs at places where human activities have been strictly prohibited. Comparing with other management scenarios, the populations in fengshui forests showed good regeneration, since the moderate anthropogenic disturbances in these forests. Therefore, fengshui forests can serve as a conservation paradigm of P. amabilis since they echo the optimum regime where anthropogenic disturbances occur.

Species Distribution Modelling of Two Sympatric Hornbills: The Great Hornbill and Rufous-Necked Hornbill in Bhutan

The great hornbill (Buceros bicornis) and rufous-necked hornbill (Aceros nepalensis) are listed as vulnerable under the International Union for Conservation of Nature Red List of threatened species due to the rapid decline of their population in the world. This research focuses on analyzing the habitat suitability of these two important bird species across Bhutan. A total of 51 presence locations were recorded from the field survey. The models were simulated using three topographic variables and 19 bioclimatic variables. The MaxEnt modelling technique was used for delineating the distribution potential habitat suitability map. The habitat suitability analysis for great hornbill and rufous-necked hornbill shows that 2% and 3% of Bhutan’s total geographical area were highly suitable, respectively. The approach of this study will be beneficial in identifying suitable areas and aid decision-makers in management and conservation of these vulnerable bird species.

Spatial Distribution and Conservation Strategies of Large Carnivores in Human-Dominated Landscape: A Case Study of Asiatic Black Bear in Jilin, China

Large carnivores maintain the balance of ecosystems. Understanding distribution and population changes are necessary prerequisites for scientific conservation strategy. The east of Jilin Province is the habitat of endangered Amur tiger (Panthera tigris altaica). The Chinese government has focused the monitoring on protecting the Amur tiger. However, little is known about Asiatic black bear (ABB, Ursus thibetanus) distribution, population dynamics in the wild, and protection awareness of local residents in Jilin Province, China. We conducted a integrative survey in mountain areas of eastern Jilin to determine ABB distribution. We explored the drivers of the distribution of ABB in Jilin using logstic regression, we further predicted the habitat suitability and potential suitable habitat of the ABB. Totally, we surveyed 112 grids (15 km × 15 km) from November 2015 to January 2019. Logistic regression analysis revealed that the main factors driving ABB distribution in Jilin are forest coverage, distance from protected areas, distance from main roads (railways and highways), and distance from water bodies. The results of questionnaire survey showed that the local residents’ understanding of ABB distribution is congruent with our field research. They believed that the number of ABBs has gradually increased in the past ten years. Nevertheless, the local residents have a negative attitude toward the ABBs, which may adversely affect efforts to protect them, possibly leading to more conflicts between humans and bears. Therefore, there is a need to consider ways to change the attitude of the locals through the strengthening of the protection propaganda and advocating management as being critical for the protection of ABBs. Our research provides a scientific basis for future conservation planning. We recommend taking local people’s attitude into consideration during conservation management strategy making to reduce human-bear conflicts and promote the coexistence of humans and bears.