Potential Suitable Areas Research Articles

Simulation and Prediction of the Potential Geographical Distribution of Acer cordatum Pax in Different Climate Scenarios

By analyzing the effects of environmental variables on plants, changes in plant distribution as a result of climate oscillations can be studied, which is of great significance to plant protection and management policies. Acer cordatum Pax (Aceraceae) is a non-deciduous tree distributed in valleys and streams in eastern China. Due to the effects of changing climate (warmer, drier conditions) and human impacts, the number of wild individuals of A. cordatum has exhibited a decrease trend, which is in urgent need of protection. In this study, the maximum entropy algorithm (MaxEnt) was used to predict the potential geographical distribution of A. cordatum during the Last Interglacial (LIG), and Last Glacial Maximum (LGM), current, 2060s, and 2080s periods. The model used geographic location information of 337 A. cordatum and six climatic variables. The area under the receiver operating characteristic curves (AUC) of the simulation results were more than 0.95, indicating high accuracy in the simulation result. The mean temperature of coldest quarter, precipitation of warmest quarter, precipitation of driest month, and precipitation of seasonality were important climatic variables influencing the geographic distribution of A. cordatum. Based on the simulate results, the potential distribution areas of A. cordatum experienced a process of expansion and then contraction from LIG to the future. In the future, some potential suitable areas provinces will likely shrink (Guizhou, Fujian, and Anhui), even almost disappear (Chongqing), and the general distribution will trend to transfer in a northeastward direction. It is hoped that this study can provide a theoretical reference for the future protection of A. cordatum.

Viticultural Suitability Analysis Based on Multi-Source Data Highlights Climate-Change-Induced Decrease in Potential Suitable Areas: A Case Analysis in Ningxia, China

As a perennial plant with long productive span of 30–50 years, grapevine may experience cross-lifespan climate change, which can modify wine quality and challenge viticultural sustainability. Therefore, it is essential to evaluate the viticultural suitability by considering both current and future climate conditions. To this end, a maximum entropy model was proposed to delimitate potentially suitable areas for viticulture based on multi-source data in a novel wine region, Ningxia, China, considering both current and future climate conditions. Firstly, we combined traditional data of climate, soil, and topography with remote sensing data to screen predictors that best characterize current geographical distribution of vineyards. Then, we used those predictors to assess current suitability (2001–2020) in Ningxia. The results indicated altitude, aridity index during April–September (K0409), precipitation during July–September (P0709), normalized difference vegetation index during July–September (NDVI0709), soil organic carbon (SOC), and precipitation in September (P09) were key predictors to assess potential suitability for viticulture, and their threshold values ranged from 1075 m to 1648 m, 2.93 to 4.83, 103.1 mm to 164.1 mm, 0.1 to 0.89, 0.07 g/kg to 11 g/kg and 28.4 mm to 45.0 mm, respectively. Suitability maps revealed a total suitable area of 12029 km2, among which the highly and moderately suitable areas accounted for 6.1% and 23.1%, respectively. Finally, the alteration in proportion of potential suitable areas due to changing climate was estimated. The potential suitable areas varied from 8742 km2 to 10623 km2 over the next 40 years (2022–2060) and decreased to 8826–9184 km2 under a short-term sustainability (suitable only during current–2040). To further consider long-term and sustainable development of the wine industry (current–2060), total suitable areas dropped by 26.7–29.2% under different climate scenarios compared with current suitable areas (2001–2020). The conclusions provide indispensable guidance for vineyard zoning considering long-term climate change.

Climate change on potential suitable areas for typical Pinaceae species on the Western Sichuan Plateau

There is a significant impact of climate change on species distribution and vegetation patterns in high mountain regions, which is a major topic of research in biogeography. It has recently warmed up on the Western Sichuan Plateau, one of the most vulnerable regions to climate change. Based on the MaxEnt model, we were able to predict distributions based on current and future climate conditions, and determine the trend of distribution change and the underlying climate factors. Under current climate conditions, the two typical tree species display distinct spatial distributions. Furthermore, under future climate conditions, distribution ranges of both typical tree species will shrink and move to the northern part of the plateau. The variation in temperature between seasons and years affected the distribution of two tree species. This study provided a scientific basis for understanding how high mountain and plateau forests respond to climate change.

Modeling and Mapping Habitat Suitability of Highland Bamboo under Climate Change in Ethiopia

Highland bamboo (Oldeania alpina formerly Arundinaria alpina or Yushania alpina) is a species of significant conservation value in Afromontane ecosystems across Africa. It also plays a significant role in the livelihoods of local communities. However, global climate change is anticipated to alter its ecological niche, leading to range shifts and possible habitat contractions. This study aimed to identify potentially suitable habitats for highland bamboo in Ethiopia, determine the resilience of the species under climate change, and establish the environmental factors affecting its habitat. Species distribution modeling (SDM) was implemented in the SDM R package using 231 georeferenced presence records together with climate, topographic, and soil data. To assess climate change risks to the species, predictive models were developed assuming climate scenarios for 2061–2080 under two shared socio-economic pathways (SSPs), namely, SSP2-45 and SSP5-85. The results indicated that highland bamboo mainly grows in high elevation areas with altitudes of 2100–3100 m asl with mean annual temperatures of 11.5–19.3 °C, annual precipitation of 873–1962 mm, precipitation of the driest quarter of 36–147 mm, soil pH of 5.6, and soil CEC of 30.7 cmolc/kg. The current potentially suitable habitat for this species in Ethiopia was estimated at 61,831.58 km2, with the majority of habitats being in the southern and southwestern parts of the country. Our models predicted that the suitable habitat will shrink by 13.4% under the SSP5-85 scenario, while potential new suitable areas for this species were identified under the SSP2-45 scenario. Future vulnerable areas were mostly found in central Ethiopia. Based on the predictions, we conclude that most of the suitable habitats for highland bamboo will remain suitable between the years 2061 and 2080.

Prediction of Suitable Future Natural Areas for Highland Barley on the Qinghai-Tibet Plateau under Representative Concentration Pathways (RCPs)

Global climate change, mainly characterized by warming, has resulted in significant migration of temperature-sensitive crops from traditional planting areas, making crops more vulnerable to climate change and natural disasters, increasing yield losses caused by disasters. Based on the MaxEnt model, combining Representative Concentration Pathways 4.5 and 8.5, the potential suitable areas for highland barley planting on the Qinghai-Tibet Plateau were estimated, and the results showed that: (1) Over 30% of the Qinghai-Tibet Plateau is unsuitable for highland barley cultivation, the area of moderately suitable area for highland barley planting is close to 50%, and the marginally suitable and highly suitable area is less than 20%; (2) From the past distribution to the near and medium-term distributions, the unsuitable area for highland barley planting is gradually shrinking. In the moderately suitable area for highland barley planting, some of the area with relatively low suitability was transformed from unsuitable area, and some of the area with relatively high suitability was transformed into marginally suitable area, so that the total area remained basically unchanged. A small part of the marginally suitable area was converted into high-suitability area, which increased the highly suitable area; (3) From the perspective of different scenarios, in the near and medium term, the area with a slight decrease or no change in suitability under RCP 8.5 was smaller than under RCP 4.5, but the area with a significant increase was larger than under RCP 4.5. The areas with a small decrease or no change in suitability accounted for 23.66–33.77% of the total plateau area and were concentrated in the northwestern Qinghai-Tibet Plateau and the Qaidam Basin. Areas with a large increase in suitability accounted for 3.47–15.64% of the total area and were located in the southern, central, and eastern parts of the Qinghai-Tibet Plateau, this area increased significantly with time; (4) Judging from the average altitude change in highland barley planting, the average altitude of the highly suitable area will rise from 3759 m to 3937 m (RCP 4.5) and 3959 m (RCP 8.5) in the near term. By the medium term, the average elevation of the highly suitable area will increase from 3759 m to 4017 m (RCP 4.5) and 4090 m (RCP 8.5). The trend of rising average altitude continues to strengthen.

Will citrus geographical indications face different climate change challenges in China?

Global climate change resulting from human activities has brought opportunities and challenges to agricultural production. Therefore, we used the MaxEnt model to simulate habitat suitability for citrus geographical indications (GIs) based on nine environmental factors. Under four shared socioeconomic pathways (SSPs) in the 2050s, 2070s and 2090s, the potential suitable area changes in the four citruses (orange, pomelo, mandarin and tangerine) were studied. The results showed that the four citrus types were all severely affected by the precipitation in the driest month and the minimum temperature of the coldest month. The suitable area for citrus GIs moved north in future scenarios. It decreased in the South subtropical Humid Zone but increased in the North subtropical Humid Zone. The suitable habitats for citrus changed in three ways: (1) both the high- and low-suitability areas for the orange GI gradually increased; (2) the high-suitability areas for pomelo and mandarin GIs increased while their low-suitability areas decreased; and (3) the low-suitability area for the tangerine GI increased, while their high-suitability areas rapidly decreased. Under the SSP5–8.5 scenario in the 2090s, the highly suitable area for the tangerine GI decreased by 91.40%. The effects of climate change on the habitats of the four geographical indication-designated citruses varied. The four citrus types under the SSP1–2.6 scenarios all showed relatively minor changes when compared to the current suitable areas. Therefore, strengthening intergovernmental cooperation to achieve carbon neutrality, controlling global temperature increases and proposing a sustainable pathway under the SSP1–2.6 scenario can benefit high-quality fruit production.

Potential geographic distribution of relict plant Pteroceltis tatarinowii in China under climate change scenarios.

Pteroceltis tatarinowii (Pteroceltis: Ulmaceae) is a deciduous tree that has a cultivation history of more than 2000 years in China. As an excellent afforestation tree species and rare and endangered tertiary relic plant, P. tatarinowii has high ecological protection value. Due to the forest destruction caused by predatory logging and natural environmental factors, the population of P. tatarinowii in China has decreased significantly. In this study, the potential geographical distribution of P. tatarinowii in China under climate change was predicted using MaxEnt model and ArcGIS based on 223 effective distribution points of P. tatarinowii and 11 environmental variables. The results showed that: (1) the prediction accuracy of MaxEnt model was extremely high, and the areas under curve (AUC) value of the training data was 0.936; The area of the potential suitable habitat area of P. tatarinowii under current climate condition was 180.84×104 km2, and mainly located in the central and southeast regions of China. (2) The domain environmental variables affecting the potential geographical distribution of P. tatarinowii were min temperature of coldest month (12.1~22.7°C), isothermality (26.6~35.8), mean diurnal range 6.9~9.3°C and precipitation of wettest month (189.5 ~955.5 mm). (3) In 2050s and 2070s, compared with current (4.19×104 km2), the area of highly suitable habitat will increase by 0.2%-0.3% (RCP2.6) and 1.22%-3.84% (RCP8.5) respectively. while the poorly, moderately and total suitable habitats will decrease. The gravity center of P. tatarinowii showed a trend of migration to higher latitudes and northern regions in the future. These results will provide theoretical basis for cultivation management and resource protection of P. tatarinowii.

Locating Suitable Solid Waste Dumping Sites using Remote Sensing and GIS Techniques in Aba Municipal, South-Eastern Nigeria

In most cities of Nigeria, indiscriminate solid waste dumping sites have taken over roadways, clogging drainage systems and slowing traffic flow. Conditions arising from indiscriminate waste disposal can lead to contamination of the environment and outbreaks of diseases. The main objective of this study was to examine the existing and predict potential suitable areas for solid waste dumping in Aba municipal in South-eastern Nigeria. The data used for this study were Landsat image; elevation map, ground control point of existing solid waste dumping sites, and topographical sheets of the study area. The maps were prepared by overlay and multi-criteria thresholds of roads, settlement, slope and distance to stream, We found that that 65% of the solid waste dumping area located close to roads and clustered in densely populated areas around the city center The final predictive suitability map for locating solid waste dumpsites indicated that, 11.35sqkm (19.41%) is not suitable, 26.47sqkm (45.25%) is less suitable, 16.17sqkm (27.65%) is moderately suitable and 4.5sqkm (7.69%) is highly suitable for Solid waste disposal. The potential most suitable areas for solid waste dumping sites fall about 5000m west of Ariaria market and 10,000m south east of Umu Mba in Aba Municipal.

On the road: Anthropogenic factors drive the invasion risk of a wild solitary bee species

Complex biotic networks of invaders and their new environments pose immense challenges for researchers aiming to predict current and future occupancy of introduced species. This might be especially true for invasive bees, as they enter novel trophic interactions. Little attention has been paid to solitary, invasive wild bees, despite their increasing recognition as a potential global threat to biodiversity. Here, we present the first comprehensive species distribution modelling approach targeting the invasive bee Megachile sculpturalis, which is currently undergoing parallel range expansion in North America and Europe. While the species has largely colonised the most highly suitable areas of North America over the past decades, its invasion of Europe seems to be in its early stages. We showed that its current distribution is largely explained by anthropogenic factors, suggesting that its spread is facilitated by road and maritime traffic, largely beyond its intrinsic dispersal ability. Our results suggest that M. sculpturalis is likely to be negatively affected by future climate change in North America, while in Europe the potential suitable areas at-risk of invasion remain equally large. Based on our study, we emphasise the role of expert knowledge for evaluation of ecologically meaningful variables implemented and interpreted for species distribution modelling. We strongly recommend that the monitoring of this and other invasive pollinator species should be prioritised in areas identified as at-risk, alongside development of effective management strategies.

Projecting the Potential Distribution Areas of Ixodes scapularis (Acari: Ixodidae) Driven by Climate Change.

Simple SummaryIxodes scapularis is a vector of tick-borne diseases. Climate change is one of the main factors affecting the distribution of I. scapularis. We used the maximum entropy model to project the potential distribution and future trends of I. scapularis. The potential suitable area of I. scapularis is dynamically changing in the context of climate change and precipitation in May makes the greatest contribution to such expansion.Ixodes scapularis is a vector of tick-borne diseases. Climate change is frequently invoked as an important cause of geographic expansions of tick-borne diseases. Environmental variables such as temperature and precipitation have an important impact on the geographical distribution of disease vectors. We used the maximum entropy model to project the potential geographic distribution and future trends of I. scapularis. The main climatic variables affecting the distribution of potential suitable areas were screened by the jackknife method. Arc Map 10.5 was used to visualize the projection results to better present the distribution of potential suitable areas. Under climate change scenarios, the potential suitable area of I. scapularis is dynamically changing. The largest suitable area of I. scapularis is under SSP3-7.0 from 2081 to 2100, while the smallest is under SSP5-8.5 from 2081 to 2100, even smaller than the current suitable area. Precipitation in May and September are the main contributing factors affecting the potential suitable areas of I. scapularis. With the opportunity to spread to more potential suitable areas, it is critical to strengthen surveillance to prevent the possible invasion of I. scapularis.

First record of Cnemidochroma phyllopus (Coleoptera: Cerambycidae) in the province of Corrientes, Argentina and potential distribution in the southern part of South America.

Cnemidochroma Schmidt, 1924, a small genus of the tribe Callichromatini endemic in South America, comprises six species of which the only one recorded in Paraguay, Uruguay, Argentina and Brazil is C. phyllopus (Gurin-Mneville, 1844). The aim of this study was to estimate potential suitable areas for C. phyllopus to provide further knowledge on its current distribution. A dataset of 43 records was compiled and species distribution modelling was employed linking these occurrences with bioclimatic variables. Results indicate higher suitability conditions along the Atlantic coast of Brazil, reaching north Uruguay and extending inland to Paraguay and northern parts of Argentina. In addition, we report a new distributional record from Corrientes, Argentina.

Assessing the geographical distribution of 76 Dendrobium species and impacts of climate change on their potential suitable distribution area in China.

The geographical distribution of plant resources is of great significance for studying the origin, distribution, and evolution of species. Climate and geographical factors help shape the distribution of plant species. Dendrobium is a commonly used traditional medicine and a precious economic crop in China. Owing to the over-exploitation and increasing medicinal demand of Dendrobium species plants, systematic investigation of the geographical distribution of the plants and analysis of their potential distribution under climate change are important for protecting Dendrobium plants. We adopted DIVA-GIS to analyze the georeferenced records of 76 species of the Dendrobium species collected from 2166 herbarium records. We analyzed the eco-geographical distribution and species richness of the genus Dendrobium to simulate the distribution of current and future scenarios using MaxEnt. The results revealed the distribution of Dendrobium in 30 provinces of China, with species abundance in Yunnan, Guangxi, Guangdong, and Hainan. Our model identified the following bioclimatic variables: precipitation in the driest months and the warmest seasons, isothermality, and range of annual temperature. Among them, annual precipitation is the most crucial bioclimatic variable affecting the distribution of 16 selected Dendrobium species. The change of climate in the future will lead to an increase in habitat suitability for some Dendrobium species as follows: D. officinal 2.12%, D. hancockii by 6.00%, D. hercoglossum by 8.25%, D. devonianum by 7.71%, D. henryi by 9.40%, and D. hainanense by 13.70%. By contrast, habitat suitability will dramatically decrease for other Dendrobium species: D. chrysotoxum by 0.89%, D. chrysanthum by 12.68%, D. fimbriatum by 5.07%, D. aduncum by 11.44%, D. densiflorum by 18.47%, D. aphyllum by 8.05%, D. loddigesii by 16.45%, D. nobile by 5.41%, D. falconeri by 8.73%, and D. moniliforme by 10.61%. The reduction of these species will be detrimental to the medicinal and economic value of the genus Dendrobium. Therefore, targeted development and reasonable management strategies should be adopted to conserve these valuable resources.

Dynamic analysis of mixed forest species under climate change scenarios

The outstanding self-regulation ability of mixed forest plays an important role in maintaining ecosystem stability. However, in recent years, climate change has caused geographical changes of species. This paper studies the potential geographical location of mixed species for the first time, so as to formulate the planting plan of mixed species in suitable areas. Therefore, we use the species distribution model based on Maxent to predict the potential suitable area of Chinese Pinus tabuliformis and Ostryopsis davidiana mixed forest under the climate change scenario, and provide a scientific basis for expanding the construction of P. tabuliformis and O. davidiana mixed forest in the future under three greenhouse gas emission scenarios (RCP2.6, RCP4.5 and RCP8.5) of current and future climate (2041–2060 and 2081–2100). The simulation accuracy of Maxent model is verified by the area under receiver operating characteristic curve (AUC ). The results show that the distribution range of P. tabuliformis is much larger than that of O. davidiana in China. Under the current climate conditions, the overlapping area of medium to highly suitable growing areas of P. tabuliformis and O. davidiana is 64.40 × 104 km2, accounting for 6.71% of China's land area, mainly distributed in most areas of North China, Northeast China (Western Liaoning), Northwest China (Shaanxi, Ningxia, the Southernmost part of Inner Mongolia and Eastern Gansu) and Central China (Northern Hubei). Under the future high concentration emission scenario (RCP8.5), the overlapping area of medium to highly suitable growing areas of P. tabuliformis and O. davidiana will be reduced. Under the scenario of medium concentration climate emission (RCP 4.5), the centroids of P. tabuliformis and O. davidiana tend to migrate from west to north. The annual mean temperature (bio1) has a significant effect on the geographical distribution of P. tabuliformis and O. davidiana. In addition, the mean temperature of the driest quarter (bio9) and annual precipitation (bio12) also have a significant impact on the geographical distribution of P. tabuliformis. Similarly, there are obvious factors on the geographical distribution of O. davidiana, as well as isothermality (bio3) and precipitation of the wettest quarter (bio16), indicating that the important climate factors affecting the geographical distribution of P. tabuliformis and O. davidiana are not completely consistent. We believe that mixed forests play a positive role in coping with climate change. The research results can help decision-makers to formulate adaptation countermeasures based on climate change.

Potential geographical distribution of Anopheles gambiae worldwide under climate change

BackgroundAnopheles gambiae (An. gambiae) is considered the most effective malaria vector worldwide and is widely distributed in Africa. The purpose of this study is to determine the potential impact of climate change on An. gambiae and predict the present and future potential suitable habitat globally. MethodsIn this study, environmental variables, global occurrence data of An. gambiae, and the maximum entropy model (MaxEnt) were used to evaluate the contribution of environmental factors and predict the habitat suitability of An. gambiae under the current and future scenarios. ResultsAmong all environmental variables, isothermality (Bio3, 34.5%) contributed the most to An. gambiae distribution. Under current climate conditions, the potential suitable areas for An. gambiae are mainly located near the equator (approximately 30°N-30°S), with a total area of 16.58 million km2, including central and northern South America, a fraction of areas near the equator of North America, central and southern Africa, some tropical regions of southern Asia, and small areas of Oceania. The areas of potential suitable habitats would be reduced to varying degrees in future climate scenarios. ConclusionsPotential suitable habitats for An. gambiae may not be limited to Africa. Necessary surveillance and preventive measures should be undertaken in high-risk regions, including those outside Africa, to monitor and control the spread of An. gambiae.

Potential suitable area and niche shift of different ploidy kiwifruit

Niche shift between polyploid and diploid plants is an important requirement for the success of polyploid. Diploid, tetraploid, and hexaploid of kiwifruit distribute in different areas. Whether there is obvious niche differentiation and the major environmental factors which could influence the ecological niche of different ploidy kiwifruits are still unknown. Based on the natural distribution information collected from literature and by field works, the maximum entropy model (MaxEnt) was used to predict the potentially suitable ranges and the major climatic factors affecting distribution of different ploidy kiwifruits. Niche divergence between different ploidy kiwifruits was quantified by niche identity test. The results showed that there were obvious differences in the potential suitable areas of different ploidy kiwifruits. Diploid occurred in lower altitude Hunan foothills. Tetraploid nearly overlapped with diploid but tended to northern Guizhou and eastern Chongqing. Hexaploid were centered in Guizhou Plateau, northwestern Hunan, southwestern Hubei and southern Shanxi. Hexaploid kiwifruits preferred higher altitudes and latitudes. In addition, the hexaploid had wider highly suitable areas. Results of niche identity test showed overlapped niches between diploid and tetraploid, and different niches between diploid/tetraploid and hexaploid kiwifruits. Minimum temperature of the coldest month (Bio6) and precipitation of the driest month (Bio14) were key environmental factors driving the niche shift of ploidy kiwifruits. Polyploid kiwifruits could maintain a higher probability of existence under lower Bio6 and Bio14, which indicated more extreme niche in cold and arid mountains for polyploids.

Predicting the potential global distribution of Ageratina adenophora under current and future climate change scenarios.

AimInvasive alien species (IAS) threaten ecosystems and humans worldwide, and future climate change may accelerate the expansion of IAS. Predicting the suitable areas of IAS can prevent their further expansion. Ageratina adenophora is an invasive weed over 30 countries in tropical and subtropical regions. However, the potential suitable areas of A. adenophora remain unclear along with its response to climate change. This study explored and mapped the current and future potential suitable areas of Ageratina adenophora.LocationGlobal.TaxaAsteraceae A. adenophora (Spreng.) R.M.King & H.Rob. Commonly known as Crofton weed.MethodsBased on A. adenophora occurrence data and climate data, we predicted its suitable areas of this weed under current and future (four RCPs in 2050 and 2070) by MaxEnt model. We used ArcGIS 10.4 to explore the potential suitable area distribution characteristics of this weed and the “ecospat” package in R to analyze its altitudinal distribution changes.ResultsThe area under the curve (AUC) value (>0.9) and true skill statistics (TSS) value (>0.8) indicated excelled model performance. Among environment factors, mean temperature of coldest quarter contributed most to the model. Globally, the suitable areas for A. adenophora invasion decreased under climate change scenarios, although regional increases were observed, including in six biodiversity hotspot regions. The potential suitable areas of A. adenophora under climate change would expand in regions with higher elevation (3,000–3,500 m).Main conclusionsMean temperature of coldest quarter was the most important variable influencing the potential suitable area of A. Adenophora. Under the background of a warming climate, the potential suitable area of A. adenophora will shrink globally but increase in six biodiversity hotspot regions. The potential suitable area of A. adenophora would expand at higher elevation (3,000–3,500 m) under climate change. Mountain ecosystems are of special concern as they are rich in biodiversity and sensitive to climate change, and increasing human activities provide more opportunities for IAS invasion.

Habitat changes in the most important stopover sites for the endangered red-crowned crane in China: a large-scale study.

The red-crowned crane (Grus japonensis) is an endangered bird species that has been listed as one of the Class I National Key Protected Wild Animals of China. This study analyzed the habitat changes in the two most important stopover sites for red-crowned crane (Liao River Estuary and Yellow River Delta National Nature Reserves) from 2000 to 2015. The results showed that the landscape patterns of the important stopover sites of red-crowned crane changed obviously and the potential suitable habitat area (tidal flats and marshland) for the red-crowned crane decreased by 183.3 km2, while the area of human activities (including aquaculture waterbodies, farmland and artificial facilities) increased by 140.3 km2. Landscape fragmentation intensified, which could has negative impacts on the survival of the red-crowned crane during migration. A comparative study confirmed that the reduction in marshlands and increasing landscape fragmentation caused by human activities were the main threats in the Liao River Estuary National Nature Reserve, while human activities and natural factors (such as channel flow, rainfall, and sediment discharge) were the jointly driving factors for the reduction in suitable habitats for red-crowned cranes in the Yellow River Delta National Nature Reserve. We suggest there are some loopholes in the management of the two nature reserves, which need to be strengthened urgently in China.

Prediction of potentially suitable areas for the introduction of Magnolia wufengensis under climate change

Magnolia wufengensis, a new species of the subgenus Magnolia, has extremely high ornamental and scientific value due to its rich morphological diversity. The wild population of M. wufengensis has a narrow habitat and a sparse population, and is in a critically endangered state. Currently, the potential suitable areas for the introduction of M. wufengensis and the limiting factors affecting its distribution and the response to global warming are unclear. Hence, an optimized MaxEnt model in the ENMeval package based on 49 M. wufengensis occurrence records and 16 environmental variables were used to simulate the potential suitable areas for M. wufengensis under current and future (2041–2080) climate change scenarios, including four representative concentration pathways (RCP2.6, RCP4.5, RCP6.0 and RCP8.5), to provide a scientific basis for the precise introduction, cultivation and expansion of suitable areas of M. wufengensis. The MaxEnt model was highly accurate, with an average training area under the curve (AUC) value of 0.9895 ± 0.0011 after 10 repetitions. The results indicated that the mean temperature of the coldest quarter (-6.75–14.31 °C), mean diurnal range (≤14.29 °C), min temperature of the coldest month (-13.73–10.77 °C), mean temperature of the warmest quarter (≥12.93 °C), precipitation of the wettest month (40.99–715.42 mm) and annual mean temperature (4.47–24.56 °C) were the most important environmental variables (threshold) limiting the distribution of suitable areas for M. wufengensis. In the current climate, areas of 146.15 × 104 km2, 119.88 × 104 km2 and 224.87 × 104 km2 were projected as potential areas with high, medium, and low suitability for M. wufengensis, respectively. These areas were mainly located in eastern and central Asia, the Mediterranean coast of southern Europe, and western America. Under future climate change, the potential suitable areas for M. wufengensis in the world will be greatly reduced, and the degree of fragmentation will increase. In addition, the reduction in suitable areas of different classes will be approximately 4.75%-39.14%, the suitable areas in western America and southern Europe will disappear, and the centroids of suitable areas for M. wufengensis will tends shift northeast.

Predicting the current and future suitable habitat distribution of the medicinal tree Oroxylum indicum (L.) Kurz in India

Identifying the distributional range and climatically suitable habitat of a species are crucial for developing an effective conservation strategy. This study aims to simulate the current distribution of climatically suitable habitat for a threatened medicinal tree, Oroxylum indicum (L.) Kurz in India and predict its possible range shifts in future climate scenario. Combined with 19 bioclimatic variables from WorldClim, we used Maxent to predict the potential suitable areas for species in current climatic condition and future climate under three Representative Concentration Pathway (RCP) scenarios by integrating three General Circulation Models (GCMs) for 2050 and 2070. Furthermore, we performed change analysis to identify the precise difference between the current and future distribution of suitable areas of the species for delineating habitat range expansion (gain), habitat contraction (loss) and stable habitats. The model predicted ∼25.47 % of the geographical area in India is presently climatically suitable for the species. The study revealed that annual precipitation, precipitation of wettest and warmest quarter, precipitation of wettest month, maximum temperature of warmest month and mean temperature of warmest quarter significantly influence the distribution of the studied species. The net habitat loss under three RCP scenarios (RCP 4.5, 6.0 and 8.5) was estimated to range from 10.51 % to 17.31 % for the year 2050, which could further increase 16.63%–20.40% by the year 2070. The finding indicates that rise in temperature could significantly reduce the potential habitat of O. indicum and hence suitable measures need to be taken to conserve this important medicinal plant.

Predicting the Potential Geographic Distribution of Sirex nitobei in China under Climate Change Using Maximum Entropy Model

Sirex nitobei, an Asian native wood wasp species, is a major pest in coniferous commercial forestry, infesting and weakening conifers through its obligate mutualism with a wood-rotting fungus species. The combination of wood wasp larvae and obligate mutualistic fungus causes the breakdown of plant vascular tissue, leading to the weakening of the plant and eventually to death, as well as a high economic cost in commercial forestry. Since it was first recorded in China in the early 1980s, S. nitobei has widely spread and become successfully established. Despite its extensive distribution range, little is known about the factors influencing current and future distribution patterns for potential pest control and monitoring. We used a maximum entropy model in conjunction with climate variables and shared socio-economic pathways to predict the current and future distribution of S. nitobei in China. We used the jackknife method and correlation analysis to select the bioclimatic and environmental variables that influence the geographic distribution of S. nitobei, which resulted in the inclusion of the monthly total precipitation in July (prec7), the monthly average maximum temperature in February (tmax2), the monthly average minimum temperature in July (tmin7), the monthly total precipitation in December (prec12), and isothermality (bio3). We found that precipitation and temperature influenced the potentially suitable areas, as predicted by the maximum entropy model. Moreover, the association of the fungus, the wood wasp, and the host plant impacts are related to availability of moisture and temperature, where moisture affects the growth of the fungus, and temperature influences the emergence, development and growth of larvae. Under the current climate conditions, the total potential suitable areas increased by 18.74%, while highly suitable and moderately suitable areas increased by 28.35 and 44.05%, respectively, under the 2081–2100 ssp245, 370 scenarios. Favorable conditions under climate change, low rainfall, and high temperature will favor the speedy larval development, the growth of its obligate nutritional fungal mutualist and the ability of S. nitobei to rapidly spread in previously unsuitable areas.