The impact of climate change on the distribution of two threatened Dipterocarp trees

Two ecologically and economically important, and threatened Dipterocarp trees Sal (Shorea robusta) and Garjan (Dipterocarpus turbinatus) form mono‐specific canopies in dry deciduous, moist deciduous, evergreen, and semievergreen forests across South Asia and continental parts of Southeast Asia. They provide valuable timber and play an important role in the economy of many Asian countries. However, both Dipterocarp trees are threatened by continuing forest clearing, habitat alteration, and global climate change. While climatic regimes in the Asian tropics are changing, research on climate change‐driven shifts in the distribution of tropical Asian trees is limited. We applied a bioclimatic modeling approach to these two Dipterocarp trees Sal and Garjan. We used presence‐only records for the tree species, five bioclimatic variables, and selected two climatic scenarios (RCP4.5: an optimistic scenario and RCP8.5: a pessimistic scenario) and three global climate models (GCMs) to encompass the full range of variation in the models. We modeled climate space suitability for both species, projected to 2070, using a climate envelope modeling tool “MaxEnt” (the maximum entropy algorithm). Annual precipitation was the key bioclimatic variable in all GCMs for explaining the current and future distributions of Sal and Garjan (Sal: 49.97 ± 1.33; Garjan: 37.63 ± 1.19). Our models predict that suitable climate space for Sal will decline by 24% and 34% (the mean of the three GCMs) by 2070 under RCP4.5 and RCP8.5, respectively. In contrast, the consequences of imminent climate change appear less severe for Garjan, with a decline of 17% and 27% under RCP4.5 and RCP8.5, respectively. The findings of this study can be used to set conservation guidelines for Sal and Garjan by identifying vulnerable habitats in the region. In addition, the natural habitats of Sal and Garjan can be categorized as low to high risk under changing climates where artificial regeneration should be undertaken for forest restoration.     

气候振荡背景下宁夏枸杞地理分区变迁研究

宁夏枸杞在中国北方广泛分布,重建宁夏枸杞的历史地理分布格局,确定其环境分布限制,为其种质资源保护和植物形成与进化趋势研究提供理论依据。该研究以宁夏枸杞(Lycium barbarum)为代表,采用MaxEnt模型对该物种228例野生有效分布点和19个环境变量进行评估,以明确影响其分布的相关环境因子;并对末次间冰期以来不同时期的地理分布格局进行建模分析,以揭示在气候变暖条件下宁夏枸杞适宜分布区的变化趋势,预测未来(2050s和2070s)在RCP2.6、RCP4.5和RCP6.0三种CO₂排放情景下宁夏枸杞的潜在地理分布变化。结果表明：(1)温度对宁夏枸杞的分布至关重要,其中最冷季度平均温度是影响该物种分布最重要的气候因子。(2)所建模型对宁夏枸杞的适宜分布区的模拟结果与当今实际分布一致,但分布区域比实际分布区域大。(3)宁夏枸杞的适宜分布区面积在末次冰盛期进行了收缩,而在末次间冰期分布区面积明显扩大(最大为4.23×10⁶ km²),并呈现出向北推进和向南退缩的趋势。(4)在未来3种气候情景下宁夏枸杞的适宜分布区面积均趋于缩小;随着气候变暖的加剧,宁夏枸杞适宜分布区将向高纬度和高海拔地区迁移,且生境破碎化现象比现在更加严重。(5)在RCP2.6 2070s情景下,宁夏枸杞质心向西迁移108.66 km;在RCP6.0 2070s情景下,宁夏枸杞质心向东北迁移30.23 km。研究认为,宁夏枸杞的分布格局对气候变化具有强烈响应,随着气候变暖,宁夏枸杞的适宜分布区将向高纬度和高海拔地区迁移。     

Impact of Climate Change on Potential Distribution of Chinese Caterpillar Fungus (Ophiocordyceps sinensis) in Nepal Himalaya

Climate change has already impacted ecosystems and species and substantial impacts of climate change in the future are expected. Species distribution modeling is widely used to map the current potential distribution of species as well as to model the impact of future climate change on distribution of species. Mapping current distribution is useful for conservation planning and understanding the change in distribution impacted by climate change is important for mitigation of future biodiversity losses. However, the current distribution of Chinese caterpillar fungus, a flagship species of the Himalaya with very high economic value, is unknown. Nor do we know the potential changes in suitable habitat of Chinese caterpillar fungus caused by future climate change. We used MaxEnt modeling to predict current distribution and changes in the future distributions of Chinese caterpillar fungus in three future climate change trajectories based on representative concentration pathways (RCPs: RCP 2.6, RCP 4.5, and RCP 6.0) in three different time periods (2030, 2050, and 2070) using species occurrence points, bioclimatic variables, and altitude. About 6.02% (8,989 km²) area of the Nepal Himalaya is suitable for Chinese caterpillar fungus habitat. Our model showed that across all future climate change trajectories over three different time periods, the area of predicted suitable habitat of Chinese caterpillar fungus would expand, with 0.11–4.87% expansion over current suitable habitat. Depending upon the representative concentration pathways, we observed both increase and decrease in average elevation of the suitable habitat range of the species.     

Predicting the distributions of Pouteria adolfi-friederici and Prunus africana tree species under current and future climate change scenarios in Ethiopia

Distributions of potential ranges of plant species are not yet fully known in Ethiopia where high climatic variability and vegetation types are found. This study was undertaken to predict distributions of suitable habitats of Pouteria adolfi-friederici and Prunus africana under current and two future climate scenarios (RCP 4.5 and RCP 8.5 in 2050 and 2070) in Ethiopia. Eleven environmental variables with less correlation coefficients (r < 0.7) were used to make the prediction. Shifting in extents of habitat suitability and effects of elevation, solar radiation and topographic position in relation to the current and future climatic scenarios were statistically analysed using independent t-test and linear model. We found decreasing area of highly suitable habitat from 0.51% to 0.46%, 0.36% and 0.33%, 0.24% for Prunus africana and 1.13% to 1.02%, 0.77% and 0.76%, 0.60% for Pouteria adolfi-friederici, under RCP 4.5 and RCP 8.5 by 2050 and 2070 respectively. Moist and dry afromontane forests are identified as the most suitable habitat for both species. Overall, our results suggest that climate change can promote dynamic suitable habitat niches under different future climate scenarios. Therefore, biodiversity conservation strategies should take into account habitat suitability dynamics issues and identify where to conserve species before implementing conservation practices.     

Dispersal limitations increase vulnerability under climate change for reptiles and amphibians in the southwestern United States

Species conservation plans frequently rely on information that spans political and administrative boundaries, especially when predictions are needed of future habitat under climate change; however, most species conservation plans and their requisite predictions of future habitat are often limited in geographical scope. Moreover, dispersal constraints for species of concern are not often incorporated into distribution models, which can result in overly optimistic predictions of future habitat. We used a standard modeling approach across a suite of 23 taxa of amphibians and reptiles in the North American deserts (560,024 km² across 13 ecoregions) to assess impacts of climate change on habitat and combined landscape population dispersal simulations with species distribution modeling to reduce the risk of predicting future habitat in areas that are not available to species given their dispersal abilities. We used 3 general circulation models and 2 representative concentration pathways (RCPs) to represent multiple scenarios of future habitat potential and assess which study species may be most vulnerable to changes forecasted under each climate scenario. Amphibians were the most vulnerable taxa, but the most vulnerable species tended to be those with the lowest dispersal ability rather than those with the most specialized niches. Under the most optimistic climate scenario considered (RCP 2.6; a stringent scenario requiring declining emissions from 2020 to near zero emissions by 2100), 76% of the study area may experience a loss of >20% of the species examined, while up to 87% of the species currently present may be lost in some areas under the most pessimistic climate scenario (RCP 8.5; a scenario wherein greenhouse gases continue to increase through 2100 based on trajectories from the mid-century). Most areas with high losses were concentrated in the Arizona and New Mexico Plateau ecoregion, the Edwards Plateau in Texas, and the Southwestern Tablelands in New Mexico and Texas, USA. Under the most pessimistic climate scenario, all species are predicted to lose some existing habitat, with an average of 34% loss of extant habitat across all species. Even under the most optimistic scenario, we detected an average loss of 24% of extant habitat across all species, suggesting that changing climates may influence the ranges of reptiles and amphibians in the Southwest.     

未来气候变化对不同国家茶适宜分布区的影响

茶是对气候变化敏感的重要经济作物, 评价全球气候变化对茶分布和生产的影响对相关国家经济发展和茶农的生计至关重要。本研究基于全球858个茶分布点和6个气候因子数据, 利用物种分布模型预测全球茶的潜在适宜分布区及其在2070年的不同温室气体排放情景(RCP2.6和RCP8.5)下的变化。结果表明: 当前茶在五大洲均有适宜分布区, 主要集中在亚洲、非洲和南美洲, 并且最冷季平均温和最暖季降水量主导了茶的分布。预计2070年, 茶的适宜分布区变化在不同的大洲、国家和气候情景间将存在差异。具体来说, 茶的适宜分布区总面积将会减少, 减少的区域主要位于低纬度地区, 而中高纬度地区的适宜分布区将扩张, 由此可能导致茶的适宜分布区向北移动; 重要的产茶国中, 阿根廷、缅甸、越南等茶适宜分布区面积会减少57.8%-95.8%, 而中国和日本的适宜分布面积则会增加2.7%-31.5%。未来全球新增的适宜分布区中, 约有68%的地区土地覆盖类型为自然植被, 因此可能导致新茶树种植园的开垦和自然植被及生物多样性保护产生冲突。     

Impact of climate change on vector transmission of Trypanosoma cruzi (Chagas, 1909) in North America

Climate change can influence the geographical range of the ecological niche of pathogens by altering biotic interactions with vectors and reservoirs. The distributions of 20 epidemiologically important triatomine species in North America were modelled, comparing the genetic algorithm for rule‐set prediction (GARP) and maximum entropy (MaxEnt), with or without topographical variables. Potential shifts in transmission niche for Trypanosoma cruzi (Trypanosomatida: Trypanosomatidae) (Chagas, 1909) were analysed for 2050 and 2070 in Representative Concentration Pathway (RCP) 4.5 and RCP 8.5. There were no significant quantitative range differences between the GARP and MaxEnt models, but GARP models best represented known distributions for most species [partial‐receiver operating characteristic (ROC) > 1]; elevation was an important variable contributing to the ecological niche model (ENM). There was little difference between niche breadth projections for RCP 4.5 and RCP 8.5; the majority of species shifted significantly in both periods. Those species with the greatest current distribution range are expected to have the greatest shifts. Positional changes in the centroid, although reduced for most species, were associated with latitude. A significant increase or decrease in mean niche elevation is expected principally for Neotropical 1 species. The impact of climate change will be specific to each species, its biogeographical region and its latitude. North American triatomines with the greatest current distribution ranges (Nearctic 2 and Nearctic/Neotropical) will have the greatest future distribution shifts. Significant shifts (increases or decreases) in mean elevation over time are projected principally for the Neotropical species with the broadest current distributions. Changes in the vector exposure threat to the human population were significant for both future periods, with a 1.48% increase for urban populations and a 1.76% increase for rural populations in 2050.     

未来气候变化对粤港澳地区杜鹃花适生区的影响

位于我国南方丘陵的粤港澳地区拥有丰富杜鹃花资源,长期以来受杜鹃花不适宜在高温低海拔地区进行开发利用等思想的影响,该区域野生杜鹃花的开发、保护与利用研究寥寥无几,但低海拔野生杜鹃花在气候变化下正面临较高灭绝风险。基于粤港澳地区杜鹃花属(Rhododendron)14个筛选后的野生物种229个标本点位数据,利用最大熵模型(Maxent)模拟粤港澳地区野生杜鹃花在2070年低、中、高3种温室气体排放模式(RCP2.6、RCP4.5、RCP8.5)下的适生区范围大小与方向的变化及其主导环境变量。研究发现未来粤港澳地区野生杜鹃花的适生区范围整体呈缩小趋势,且随着温室气体排放浓度的增加,即从RCP2.6到RCP8.5,越来越多杜鹃花物种适生区呈现向高纬度、高海拔方向迁移的趋势;对杜鹃花分布影响最大的变量为最冷月的最低温、温度季节性和最干月降水量。本研究通过探究气候变化对野生杜鹃花适生区范围的影响,以期为粤港澳地区野生杜鹃花的保护与开发利用提供科学指导。     

Distance,elevation and environment as drivers of diversity and divergence in bumble bees across latitude and altitude

Identifying drivers of dispersal limitation and genetic differentiation is a key goal in biogeography. We examine patterns of population connectivity and genetic diversity using restriction site‐associated DNA sequencing (RADseq) in two bumble bee species, Bombus vosnesenskii and Bombus bifarius, across latitude and altitude in mountain ranges from California, Oregon and Washington, U.S.A. Bombus vosnesenskii, which occurs across a broader elevational range at most latitudes, exhibits little population structure while B. bifarius, which occupies a relatively narrow higher elevation niche across most latitudes, exhibits much stronger population differentiation, although gene flow in both species is best explained by isolation with environmental niche resistance. A relationship between elevational habitat breadth and genetic diversity is also apparent, with B. vosnesenskii exhibiting relatively consistent levels of genetic diversity across its range, while B. bifarius has reduced genetic diversity at low latitudes, where it is restricted to high‐elevation habitat. The results of this study highlight the importance of the intersect between elevational range and habitat suitability in influencing population connectivity and suggest that future climate warming will have a fragmenting effect even on populations that are presently well connected, as they track their thermal niches upward in montane systems.     

孑遗植物长苞铁杉(Tsuga longibracteata)分布格局对未来气候变化的响应

长苞铁杉(Tsuga longibracteata)是中国特有的珍贵树种,不仅对研究裸子植物的系统发育、古生态和古气候具有重要作用,而且该树种具有造林、用材和药用等方面的较高价值。研究长苞铁杉在气候变化下的分布格局变化是制定其保护和可持续利用的重要基础。采用最大熵模型(MaxEnt),结合不同时期(当前、2050年和2070年)和不同二氧化碳排放情境下(RCP2.6和RCP8.5)的气候因子变量,探讨气候变化与物种地理分布格局的关系,预测长苞铁杉的潜在分布区变迁。本研究考虑了空间约束对物种分布的限制作用,构建了气候因子预测模型(C)和气候+空间约束因子预测模型(C+S)分别进行潜在分布区预测,比较其结果差异。结果显示,最干月降水量和温度年较差是影响长苞铁杉地理分布的主导气候因子,空间约束因子对长苞铁杉未来的地理分布有重要影响。随时间年限增加,长苞铁杉总潜在适生区面积降低,特别是中高等级的适生区面积有不同程度地减少,分布范围总体向北移动,这些变化趋势在RCP8.5情境下更加突出。这一结果表明未来气候变化会导致长苞铁杉种群分布范围收缩和生境适宜度下降,加剧其受胁程度。加入空间约束因子后,C+S模型的预测精度更高,结果更符合长苞铁杉的迁移、扩散特性。长苞铁杉未来的核心分布区仍位于现存的湘、桂、黔结合部,表明其具有"原地避难"的特性,应进一步加强对现有野生资源的保护。渝、川、鄂结合部的大巴山等地区是未来气候变化下长苞铁杉的理论分布区域,可作为长苞铁杉应对未来气候变化的引种地区,应提早进行人工引种、栽培等前期研究。研究结果可为气候变化背景下长苞铁杉的保护、物种迁地保存和可持续管理提供科学依据,也可为准确预测濒危、珍稀植物的地理分布范围提供方法参考。     

Projecting the future of an alpine ungulate under climate change scenarios

Climate change represents a primary threat to species persistence and biodiversity at a global scale. Cold adapted alpine species are especially sensitive to climate change and can offer key “early warning signs” about deleterious effects of predicted change. Among mountain ungulates, survival, a key determinant of demographic performance, may be influenced by future climate in complex, and possibly opposing ways. Demographic data collected from 447 mountain goats in 10 coastal Alaska, USA, populations over a 37‐year time span indicated that survival is highest during low snowfall winters and cool summers. However, general circulation models (GCMs) predict future increase in summer temperature and decline in winter snowfall. To disentangle how these opposing climate‐driven effects influence mountain goat populations, we developed an age‐structured population model to project mountain goat population trajectories for 10 different GCM/emissions scenarios relevant for coastal Alaska. Projected increases in summer temperature had stronger negative effects on population trajectories than the positive demographic effects of reduced winter snowfall. In 5 of the 10 GCM/representative concentration pathway (RCP) scenarios, the net effect of projected climate change was extinction over a 70‐year time window (2015–2085); smaller initial populations were more likely to go extinct faster than larger populations. Using a resource selection modeling approach, we determined that distributional shifts to higher elevation (i.e., “thermoneutral”) summer range was unlikely to be a viable behavioral adaptation strategy; due to the conical shape of mountains, summer range was expected to decline by 17%–86% for 7 of the 10 GCM/RCP scenarios. Projected declines of mountain goat populations are driven by climate‐linked bottom‐up mechanisms and may have wide ranging implications for alpine ecosystems. These analyses elucidate how projected climate change can negatively alter population dynamics of a sentinel alpine species and provide insight into how demographic modeling can be used to assess risk to species persistence.     

Back home? Uncertainties for returning seized animals to the source‐areas under climate change

Regardless of the economic, social and environmental impacts caused by wild animal trafficking worldwide, the suitable destination of seized specimens is one of the main challenges faced by environmental managers and authorities. In Brazil, returning seized animals to the wild has been the most frequent path in population restoration programs, and has been carried out, as a priority, in areas where the animals were captured. However, in addition to the difficulty in identifying the locations of illegal captures, little scientific knowledge is available on the future viability of the source‐areas to global climate change. Thus, the current work aims to evaluate the impacts of climate change on the main source‐municipalities for animal trafficking in Brazil, referred to herein as source‐areas. For this, using ecological niche modeling, the environmental suitability of the source‐areas for illegal animal captures was evaluated in two scenarios at two different time horizons: optimistic (RCP 26) and pessimistic (RCP 85) emission scenarios in both 2050 and 2070 projections. Moreover, the source‐areas were compared with the Brazilian Federal protected areas, used here as the control group. According to the results, Brazilian source‐municipalities are not always the best option for maintaining the most seized species in the future simulations, and, therefore, seem not be the best option for projects that aim for the return of these animals to the wild. In this sense, despite the genetic and ecological issues inherent in translocation projects, our results suggest that population restoration programs for seized species need to be rethought, and furthermore other suitable areas could be considered for truly ensuring the survival and maintenance of overexploited populations in the long term.     

Invasive fountain grass (Pennisetum setaceum (Forssk.) Chiov.) increases its potential area of distribution in Tenerife island under future climatic scenarios

Mapping the distribution of invasive species under current and future climate conditions is crucial to implement sustainable and effective conservation strategies. Several studies showed how invasive species may benefit from climate change fostering their invasion rate and, consequently, affecting the native species community. In the Canary Islands and on Tenerife in particular, previous research mostly focused on climate change impacts on the native communities, whereas less attention has been paid on alien species distribution under climate change scenarios. In this study, we modelled the habitat distribution of Pennisetum setaceum, one of the most invasive alien species on Tenerife. In addition, we described the species’ potential distribution shift in the light of two climate change scenarios (RCP2.6, RCP8.5), highlighting the areas that should be prioritized during management and eradication programs. P. setaceum’s suitable areas are located in the coastal area, with higher habitat suitability near cities and below 800 m asl. In both future climate change scenarios, the geographic distribution of P. setaceum suitable areas is characterized by an elevational shift, which is more pronounced in the RCP8.5 scenario. Despite being drought resistant, water supply is crucial for the species’ seed germination, thus supporting future species’ shift to higher elevation and in the north–north–west part of the island, where it could benefit from the combined effect of orographic precipitations and humidity carried by trade winds.

     

气候变化情景下外来入侵植物刺苍耳在新疆的潜在分布格局模拟

明确区域尺度上外来入侵种的潜在分布格局及其对气候变化的响应对入侵种的预防和控制具有重要意义。以外来入侵植物刺苍耳(Xanthium spinosum L.)为研究对象,以其扩散蔓延的新疆地区为研究区域,结合中国国家气候中心开发的BCC—CSM1—1模式下的将来气候条件,应用MaxEnt模型和ArcGIS空间分析技术构建了未来不同气候变化情景(RCP4.5,8.5)下2050s和2070s的刺苍耳适宜生境预测模型,定量的展示了气候变化情景下刺苍耳在新疆的扩散趋势及其适宜生境的面积空间变化和分布区中心移动轨迹。结果表明:年降雨量、下层土壤有机碳含量、上层土壤pH值、年温度变化范围、降雨量的季节性变化和年平均温度是影响刺苍耳地理分布的主导环境因子;博州、塔城、阿勒泰西北部、哈密中部、巴州北部、克州中部、阿克苏北部、奎屯市、克拉玛依市、五家渠市、喀什市等地为高危入侵风险区;两种气候模式下刺苍耳的各级适生区面积和总适生面积均呈持续增加的变化趋势,且在RCP8.5情景(最高温室气体排放情景)下响应更为敏感;总体上看,刺苍耳在新疆的分布未达到饱和,呈现以塔城中部为中心,向天山北麓和塔克拉玛干北缘方向辐射状扩散,且两种气候变化情景下至2070s分布区中心均向伊犁州奎屯方向移动。     

Potential Effects of Climate Change on the Distribution of Cold-Tolerant Evergreen Broadleaved Woody Plants in the Korean Peninsula

Climate change has caused shifts in species’ ranges and extinctions of high-latitude and altitude species. Most cold-tolerant evergreen broadleaved woody plants (shortened to cold-evergreens below) are rare species occurring in a few sites in the alpine and subalpine zones in the Korean Peninsula. The aim of this research is to 1) identify climate factors controlling the range of cold-evergreens in the Korean Peninsula; and 2) predict the climate change effects on the range of cold-evergreens. We used multimodel inference based on combinations of climate variables to develop distribution models of cold-evergreens at a physiognomic-level. Presence/absence data of 12 species at 204 sites and 6 climatic factors, selected from among 23 candidate variables, were used for modeling. Model uncertainty was estimated by mapping a total variance calculated by adding the weighted average of within-model variation to the between-model variation. The range of cold-evergreens and model performance were validated by true skill statistics, the receiver operating characteristic curve and the kappa statistic. Climate change effects on the cold-evergreens were predicted according to the RCP 4.5 and RCP 8.5 scenarios. Multimodel inference approach excellently projected the spatial distribution of cold-evergreens (AUC = 0.95, kappa = 0.62 and TSS = 0.77). Temperature was a dominant factor in model-average estimates, while precipitation was minor. The climatic suitability increased from the southwest, lowland areas, to the northeast, high mountains. The range of cold-evergreens declined under climate change. Mountain-tops in the south and most of the area in the north remained suitable in 2050 and 2070 under the RCP 4.5 projection and 2050 under the RCP 8.5 projection. Only high-elevations in the northeastern Peninsula remained suitable under the RCP 8.5 projection. A northward and upper-elevational range shift indicates change in species composition at the alpine and subalpine ecosystems in the Korean Peninsula.     

Current and future distributions of Espeletiinae (Asteraceae) in the Venezuelan Andes based on statistical downscaling of climatic variables and niche modelling

ABSTRACT

Background: Páramos are the high-elevation ecosystems of the humid tropical Andes, characterised by the presence of giant rosettes of the Espeletiinae subtribe (Asteraceae). Forecasted climate change is likely to reduce the extent of the area climatically suitable/occupied currently by Espeletiinae and their elevation distribution patterns.

Aims: The aim of this study was to estimate the potential impacts of forecasted climate change on the geographic distribution (extent of area and elevation distribution patterns) of 28 species of Espeletiinae that have been recorded in the Cordillera de Mérida, Venezuela.

Methods: Six bioclimatic variables, downscaled to a 90 m × 90 m cell size, were used to construct species distribution models (SDM) for the 28 species to model their current and likely future distribution (2070) by using two general circulation models and four representative concentration pathways (RCP).

Results: Nine species were estimated to have potential distribution over less than 1000 km² and five over less than 500 km², in current climatic conditions. Fifteen and eight species had elevation spans narrower than 1000 m and 500 m, respectively. No significant differences in modelled areas or spans were detected between north, central and south sections of the Cordillera de Mérida. Mean ± SE future reduction in the extent of area climatically suitable were estimated between 51.3% ± 6.3% (RCP2.6) and 78.1% ± 5.3% (RCP8.5), coupled with upward range retreat of between 277.8 m ± 27.4 m (RCP2.6) and 762.5 m ± 59.8 m (RCP8.5).

Conclusions: Our study predicts large reductions in modelled area and important upward shifts in the distribution of Venezuelan Espeletiinae by 2070 compared to their current distribution.     

Habitat assessment of Marco Polo sheep (Ovis ammon polii) in Eastern Tajikistan: Modeling the effects of climate change

Identifying the factors predicting the high‐elevation suitable habitats of Central Asian argali wild sheep and how these suitable habitats are affected by the changing climate regimes could help address conservation and management efforts and identify future critical habitat for the species in eastern Tajikistan. This study used environmental niche models (ENMs) to map and compare potential present and future distributions of suitable environmental conditions for Marco Polo argali. Argali occurrence points were collected during field surveys conducted from 2009 to 2016. Our models showed that terrain ruggedness and annual mean temperature had strong correlations on argali distribution. We then used two greenhouse gas concentration trajectories (RCP 4.5 and RCP 8.5) for two future time periods (2050 and 2070) to model the impacts of climate change on Marco Polo argali habitat. Results indicated a decline of suitable habitat with majority of losses observed at lower elevations (3,300–4,300 m). Models that considered all variables (climatic and nonclimatic) predicted losses of present suitable areas of 60.6% (6,928 km²) and 63.2% (7,219 km²) by 2050 and 2070, respectively. Results also showed averaged habitat gains of 46.2% (6,106 km²) at much higher elevations (4,500–6,900 m) and that elevational shifts of habitat use could occur in the future. Our results could provide information for conservation planning for this near threatened species in the region.     

How much does climate change threaten European forest tree species distributions?

Although numerous species distribution models have been developed, most were based on insufficient distribution data or used older climate change scenarios. We aimed to quantify changes in projected ranges and threat level by the years 2061–2080, for 12 European forest tree species under three climate change scenarios. We combined tree distribution data from the Global Biodiversity Information Facility, EUFORGEN, and forest inventories, and we developed species distribution models using MaxEnt and 19 bioclimatic variables. Models were developed for three climate change scenarios—optimistic (RCP2.6), moderate (RCP4.5), and pessimistic (RPC8.5)—using three General Circulation Models, for the period 2061–2080. Our study revealed different responses of tree species to projected climate change. The species may be divided into three groups: “winners”—mostly late‐successional species: Abies alba, Fagus sylvatica, Fraxinus excelsior, Quercus robur, and Quercus petraea; “losers”—mostly pioneer species: Betula pendula, Larix decidua, Picea abies, and Pinus sylvestris; and alien species—Pseudotsuga menziesii, Quercus rubra, and Robinia pseudoacacia, which may be also considered as “winners.” Assuming limited migration, most of the species studied would face a significant decrease in suitable habitat area. The threat level was highest for species that currently have the northernmost distribution centers. Ecological consequences of the projected range contractions would be serious for both forest management and nature conservation.     

Topographic,latitudinal and climatic distribution of Pinus coulteri: geographic range limits are not at the edge of the climate envelope

With changing climate, many species are projected to move poleward or to higher elevations to track suitable climates. The prediction that species will move poleward assumes that geographically marginal populations are at the edge of the species' climatic range. We studied Pinus coulteri from the center to the northern (poleward) edge of its range, and examined three scenarios regarding the relationship between the geographic and climatic margins of a species' range. We used herbarium and iNaturalist.org records to identify P. coulteri sites, generated a species distribution model based on temperature, precipitation, climatic water deficit, and actual evapotranspiration, and projected suitability under future climate scenarios. In fourteen populations from the central to northern portions of the range, we conducted field studies and recorded elevation, slope and aspect (to estimate solar insolation) to examine relationships between local and regional distributions. We found that northern populations of P. coulteri do not occupy the cold or wet edge of the species' climatic range; mid‐latitude, high elevation populations occupy the cold margin. Aspect and insolation of P. coulteri populations changed significantly across latitudes and elevations. Unexpectedly, northern, low‐elevation stands occupy north‐facing aspects and receive low insolation, while central, high‐elevation stands grow on more south‐facing aspects that receive higher insolation. Modeled future climate suitability is projected to be highest in the central, high elevation portion of the species range, and in low‐lying coastal regions under some scenarios, with declining suitability in northern areas under most future scenarios. For P. coulteri, the lack of high elevation habitat combined with a major dispersal barrier may limit northward movement in response to a warming climate. Our analyses demonstrate the importance of distinguishing geographically vs. climatically marginal populations, and the importance of quantitative analysis of the realized climate space to understand species range limits.     

美味猕猴桃地理分布模拟与气候变化影响分析

为了解气候变化对美味猕猴桃(Actinidia deliciosa)地理分布的影响,结合气候情景,采用Maxent预测美味猕猴桃的适生区的变化趋势。结果表明,基准气候和未来情景下构建的美味猕猴桃分布模型的AUC值均达到极好的标准。基准气候条件下,美味猕猴桃在中国的适生区为22°~38°N,96°~122°E,总面积为3.367 9×106 km2,高适生区位于秦岭-巴山、四川盆地东部、云贵高原东部、武陵山-巫山、武夷山脉。RCP4.5和RCP8.5情景下,美味猕猴桃在中国的高适生区面积将显著减少,中适生区面积则呈增加趋势,两种情景下高、中质心均向偏南或低纬度方向移动,RCP8.5情景下质心的迁移轨迹最长,变动范围最大。Maxent模型的准确预测对于优化猕猴桃产业结构具有重要指导意义。