Identifying conservation priority areas and predicting the climate change impact on the future habitats of endangered Nepenthes khasiana Hook.f. utilizing ecological niche modelling

Developing strategies for effective species conservation is necessary to counter the ever-fluctuating environmental conditions with increasing anthropogenic activities. Studies have proven Ecological Niche Modelling (ENM) as an effective tool for sustainable conservation. Nepenthes khasiana Hook.f. is an endangered pitcher plant facing a constant decline in population due to anthropogenic activities. This study aimed to locate the most suitable areas for re-establishing the species in natural habitats using Maximum Entropy (MaxEnt) modelling, and to forecast the effects of current and future climate conditions on its distribution throughout Northeast India. The potential suitable areas in future climate under three Representative Concentration Pathway (RCP) scenarios and in the current climate were predicted utilizing the 30 occurrence data, bioclimatic predictors, and variables from BCC-CSM1.1 model and WorldClim respectively. The results of the current study showed significant relationships among annual precipitation, precipitation in the driest month, seasonality of precipitation, annual range iso-thermality of temperature, mean diurnal range [Mean of monthly (max temp - min temp)], and the distribution of the analysed species. The optimum model performance was represented by the AUC value of 0.972 ± 0.007. The model predicted 10.70% of the NE Indian region as climatically suitable, which will expand under RCP4.5 and RCP6.0, reaching 15.35%, and 12.64%, respectively. However, this may degrade significantly under RCP8.5, reducing to 8.14%. Based on the analysis of modelling results it was found that the Nokrek belt and the Khasi hills as highly suitable regions for the reintroduction of the species. The study revalidated ENM as an effective means to identify new populations and predict the influence of climate change on the future habitat which can benefit the concurrent species management strategies.     

Increasing potential risk of a global aquatic invader in Europe in contrast to other continents under future climate change

Background

Anthropogenically-induced climate change can alter the current climatic habitat of non-native species and can have complex effects on potentially invasive species. Predictions of the potential distributions of invasive species under climate change will provide critical information for future conservation and management strategies. Aquatic ecosystems are particularly vulnerable to invasive species and climate change, but the effect of climate change on invasive species distributions has been rather neglected, especially for notorious global invaders.

Methodology/Principal Findings

We used ecological niche models (ENMs) to assess the risks and opportunities that climate change presents for the red swamp crayfish (Procambarus clarkii), which is a worldwide aquatic invasive species. Linking the factors of climate, topography, habitat and human influence, we developed predictive models incorporating both native and non-native distribution data of the crayfish to identify present areas of potential distribution and project the effects of future climate change based on a consensus-forecast approach combining the CCCMA and HADCM3 climate models under two emission scenarios (A2a and B2a) by 2050. The minimum temperature from the coldest month, the human footprint and precipitation of the driest quarter contributed most to the species distribution models. Under both the A2a and B2a scenarios, P. clarkii shifted to higher latitudes in continents of both the northern and southern hemispheres. However, the effect of climate change varied considerately among continents with an expanding potential in Europe and contracting changes in others.

Conclusions/Significance

Our findings are the first to predict the impact of climate change on the future distribution of a globally invasive aquatic species. We confirmed the complexities of the likely effects of climate change on the potential distribution of globally invasive species, and it is extremely important to develop wide-ranging and effective control measures according to predicted geographical shifts and changes.     

Modeling impacts of climate change on the potential distribution of three endemic Aloe species critically endangered in East Africa

Climate change has had a significant impact on natural ecosystems and endemic species around the world and substantial impacts are expected in the future. As a result, knowing how climate change affects endemic species can help in putting forward the necessary conservation efforts. The use of niche modeling to predict changes in species distributions under different climate change scenarios is becoming a hot topic in biological conservation. This study aimed to use the global circulation model (CMIP5) to model the current distribution of suitable habitat for three critically endangered Aloe species endemic to Kenya and Tanzania in order to determine the impact of climate change on their suitable habitat in the years 2050 and 2070. We used two representative concentration pathways scenarios (RCP4.5 and RCP8.5) to project the contraction of suitable habitats for Aloe ballyi Reynolds, A. classenii Reynolds, and A. penduliflora Baker. Precipitation, temperature and environmental variables (Potential evapotranspiration, land cover, soil sedimentary and solar radiation) have had a significant impact on the current distribution of all the three species. Although suitable habitat expansion and contraction are predicted for all the species, loss of original suitable habitat is expected to be extensive. Climate change is expected to devastate >44% and 34% of the original habitats of A. ballyi and A. classenii respectively. Based on our findings, we propose that areas predicted to contract due to climate change should be designated as key protection zones for Aloe species conservation.     

Modelling the potential distribution of endangered Prunus africana (Hook.f.) Kalkm. in East Africa

Continued harvesting and climate change are affecting the distributions of many plant species and may lead to numerous extinctions over the next century. Endangered species are likely to be a special concern, but the extent to which they are sensitive to climate is currently unclear. Species distribution modelling, if carefully implemented, can be used to assess climate sensitivity and potential climate change impacts, of tree species. We used MaxEnt algorithm for species distribution modelling to assess the potential distribution and climate change risks for a threatened Prunus africana, in East Africa. Data from different herbaria on its distribution were linked to data on climate to test hypotheses on the factors determining its distribution. Predictive models were developed and projected onto a climate scenario for 2050 to assess climate change risks. Precipitation of driest quarter and annual precipitation appeared to be the main factors influencing its distribution. Climate change was predicted to result in reductions of the species' habitats (e.g. Erasmus et al., Glob. Change Biol. 2002; 8 : 679). Prunus africana distribution is thus highly vulnerable to a warming climate and highlights the fact that both in‐situ and ex‐situ conservation will be a solution to global warming.     

The impact of climate change on the future geographical distribution range of the endemic relict tree Gleditsia caspica (Fabaceae) in Hyrcanian forests

The Caspian locust (Gleditsia caspica) is an endemic relict tree that occurs in Hyrcanian forests. Many of its habitats have been destroyed in the last half-century. This study was performed to map past geographic distributions and estimate the suitable areas and potential risks of remaining populations under future climate change. Eight bioclimatic scenarios (one with current conditions, three with future climates, and four with past conditions) were tested using the maximum entropy algorithm. The most significant factors influencing the distributions of G. caspica were precipitation in the driest month and temperature seasonality. Even under the most optimistic model (RCP2.6), many stands of G. caspica may become endangered in the eastern and central parts of the range, and the distribution of this species will probably shift to the west of the Hyrcanian forest area. Considering the increasing destruction of habitats of this species due to human activities and the expected negative effects of climate change in the future, it is recommended that nature reserves be established to protect the habitat of G. caspica. Additionally, ex situ conservation strategies, such as storing seeds using cryopreservation techniques, can ensure the long-term survival of this species in the future.     

Niche modelling to guide conservation actions in France for the endangered crayfish Austropotamobius pallipes in relation to the invasive Pacifastacus leniusculus

1. The white-clawed crayfish (Austropotamobius pallipes) is globally endangered due to the impacts of habitat modification and fragmentation, water pollution, climate change, and invasive species, particularly the signal crayfish (Pacifastacus leniusculus). These pressures have caused the decline of A. pallipes populations in Europe, demonstrating the importance of predicting the species' potential distribution under current and future conditions. Focusing on the watercourses of mainland France, we aimed to identify suitable areas for A. pallipes to guide the conservation of current populations and future introduction actions or protection measures.
2. We applied ecological niche modelling to model the potential distribution of both A. pallipes and P. leniusculus and identified locations suitable for A. pallipes only. We also assessed the potential distribution of the species under two representative concentration pathway (RCP) scenarios: RCP 2.6 and RCP 8.5, respectively describing low-warming and high-warming conditions.
3. We found that A. pallipes and P. leniusculus exploit equivalent niches in France. Despite this, under current conditions, about 5% of the study area simultaneously records a high suitability for A. pallipes and a low suitability for P. leniusculus and is therefore of significant conservation interest. This percentage remains relatively stable under RCP 2.6 for 2050 and 2100, but decreases to 2% under RCP 8.5 for 2100.
4. Ecological niche modelling can supply crucial guidance for conservation actions aimed at protecting endangered species at a national scale by identifying sites most suitable for protection and sites where climate change and invasive species constitute a threat.

     

The impact of climate change on the future distribution of priority crop wild relatives in Indonesia and implications for conservation planning

The analysis of climate change impact is essential to include in conservation planning of crop wild relatives (CWR) to provide the guideline for adequate long-term protection under unpredictable future environmental conditions. These resources play an important role in sustaining the future of food security, but the evidence shows that they are threatened by climate change. The current analyses show that five taxa were predicted to have contraction of more than 30 % of their current ranges: Artocarpus sepicanus (based on RCP 4.5 in both no dispersal and unlimited dispersal scenario and RCP 8.5 in no dispersal scenario by 2050), Ficus oleifolia (RCP 4.5 5 in both no dispersal and unlimited dispersal scenario by 2080), Cocos nucifera and Dioscorea alata (RCP 8.5 in both no dispersal and unlimited dispersal scenario by 2050), and Ficus chartacea (RCP 8.5 in both no dispersal and unlimited dispersal scenario by 2050 and 2080). It shows that the climate change impact is species-specific. Representative Concentration Pathways (RCP) of greenhouse gas (GHG) emission and dispersal scenarios influence the prediction models, and the actual future distribution range of species falls in between those scenarios. Climate refugia, holdout populations, and non-analogue community assemblages were identified based on the Protected Areas (PAs) network. PAs capacity is considered an important element in implementing a conservation strategy for the priority CWR. In areas where PAs are isolated and have less possibility to build corridors to connect each other, such as in Java, unlimited dispersal scenarios are unlikely to be achieved and assisted dispersal is suggested. The holdout populations should be the priority target for the ex situ collection. Therefore, by considering the climate refugia, PAs capacity and holdout populations, the goal of keeping high genetic variations for the long-term conservation of CWR in Indonesia can be achieved.     

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。     

The identification and conservation of climate refugia for two Colombian endemic titi (Plecturocebus) monkeys

Natural resource managers face the challenge of developing conservation plans for key species and given that anthropogenic climate change (CC) effects on biodiversity are becoming increasingly evident, the new challenge is to properly incorporate CC adaptation strategies into such plans. Thus, the objective of this study is to evaluate the potential CC effects on the climatically suitable areas for two Colombian endemic titi monkeys Plecturocebus ornatus and P. caquetensis and to identify the prospective climate refugia as macro-ecological adaptation strategies for each species. A detailed ecological niche modeling (ENM) approach was applied with the maximum entropy algorithm, using presence records and different sets of bioclimatic variables describing baseline (1960–1990) and future climates (∼2070). Models of future climatic suitability were generated using projections of variables under a stabilization (RCP4.5) and business as usual (RCP8.5) scenarios with data from two general circulation models (GCMs) describing storylines of increasing (CESM1_CAM5) and decreasing (CSIRO_ACCESS1_3) rainfall patterns. The results for both species indicate that in a warmer future, opposite rainfall patterns and choice of the bioclimatic variables may lead to divergent responses on the extent and geographic distribution of their climatic niche, which varied from regions gaining, losing, and retaining suitability in potential climate refugia. Moreover, CC represents a serious threat for P. caquetensis and P. ornatus since their ranges may be largely exposed to novel climates. Their baseline climatic suitability area is projected to shrink and shift to higher elevations in the Andes mountains, and the climate refugia identified for both species are poorly covered by protected areas. Therefore, the climate refugia identified in this work and the management recommendations offered should be considered by species conservation plans to contribute to the selection of priority regions for conservation actions. The modeling approach reveals the uncertainties arising from the selection of bioclimatic variables and GCMs in ENM, which can be replicated to identify climate refugia targeting different species of conservation concern.     

气候变化对新疆雪岭云杉潜在适宜分布及生态位分化的影响

探究气候变化对天山森林植物潜在空间分布的影响及其模拟预测有助于揭示中尺度下植物分布格局对气候变化的适应对策和反馈机制,对促进干旱区山地森林生态系统的生物多样性保育和森林资源可持续管理有着重要的科学和实践意义。基于雪岭云杉的分布点数据和环境因子数据,利用最大熵(MaxEnt)模型、GIS工具及R软件估计其在基准气候(1970—2000年)及2050(2041—2060年)和2070(2061—2080年)时段基于RCPs气候情景下的潜在分布范围、空间格局变化及生态位分化。结果表明：(1)雪岭云杉在基准气候下的潜在分布与2019年秋季的NDVI植被覆盖变化基本保持一致,高适生分布区主要分布在东疆的哈密、巴里坤和伊吾,北疆主要分布在天山北坡、博格达山、北塔山和伊犁河谷,南疆主要分布在天山南坡。另外,在阿尔泰山南坡、塔城、裕民、托里、西昆仑山和小帕米尔山地也有分布。(2)限制雪岭云杉潜在分布的关键因子为降水(最干月降水量、最冷季降水量和降水季节性)和温度(最干季平均温度、年均温、等温性和气温年较差)、土壤剖面有效含水量、土壤碳密度及海拔,其累计贡献率之和达到87.28%。(3)2050和207...     

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。     

Predicting range shifts of Davidia involucrata Ball. under future climate change

Understanding and predicting how species will respond to climate change is crucial for biodiversity conservation. Here, we assessed future climate change impacts on the distribution of a rare and endangered plant species, Davidia involucrate in China, using the most recent global circulation models developed in the sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC6). We assessed the potential range shifts in this species by using an ensemble of species distribution models (SDMs). The ensemble SDMs exhibited high predictive ability and suggested that the temperature annual range, annual mean temperature, and precipitation of the driest month are the most influential predictors in shaping distribution patterns of this species. The projections of the ensemble SDMs also suggested that D. involucrate is very vulnerable to future climate change, with at least one‐third of its suitable range expected to be lost in all future climate change scenarios and will shift to the northward of high‐latitude regions. Similarly, at least one‐fifth of the overlap area of the current nature reserve networks and projected suitable habitat is also expected to be lost. These findings suggest that it is of great importance to ensure that adaptive conservation management strategies are in place to mitigate the impacts of climate change on D. involucrate.     

Climate change aggravates anthropogenic threats of the endangered savanna tree Pterocarpus erinaceus (Fabaceae) in Burkina Faso

Species distribution modelling is gaining popularity due to significant habitat shifts in many plant and animal species caused by climate change. This issue is particularly pressing for species that provide significant ecosystem goods and services. A prominent case is the valuable African rosewood tree (Pterocarpus erinaceus) that is threatened in sub-Saharan Africa, while its present distribution, habitat requirements and the impact of climate change are not fully understood. This native species naturally occurs in various savanna types, but anthropogenic interventions have considerably reduced its natural populations in the past decades. In this study, ensemble modelling was used to predict the current and future distribution potential of the species in Burkina Faso. Fifty-four environmental variables were selected to describe its distribution in the years 2050 and 2070 based on the greenhouse gas concentration trajectories RCP4.5 and 8.5, and the general circulation models CNRM-CM5 and HadGEM2-CC. A network of protected areas in Burkina Faso was also included to assess how many of the suitable habitats may contribute to the conservation of the species. The factors isothermality (31%), minimum temperature of coldest month (31%), pH in H₂O at horizon 0–5 cm (11%), silt content at horizon 60–100 cm (9.2%) and precipitation of warmest quarter (8%) were the most influential distribution drivers for the species. Under current climate conditions, potentially highly suitable habitats cover an area of 129,695 km², i.e., 47% of Burkina Faso. The projected distribution under RCP4.5 and 8.5 showed that this area will decrease, and that the decline of the species will be pronounced. The two models used in this study, forecast a habitat loss of up to 61% for P. erinaceus. Hence, development and implementation of a conservation programme are required to save the species in its native range. This study will help land managers prioritise areas for protection of the species, and avoid introducing it to inappropriate areas unless suitable conditions are artificially created through the management options applied.     

Effects of Climate Change on <Emphasis Type="Italic">Paralaudakia lehmanni</Emphasis> (Nicolsky, 1896) (Reptilia: Agamidae) in Central Asia

Climate change and global warming are the main challenges regarding to the conservation biologists on the world. Reptiles are ectothermic animal and then highly dependent on the habitat temperature and precipitation. To protect reptiles, it is necessary to predict the impact of climate change effect on the species distribution and manage its conservation program. In this study, we aimed to evaluate the impact of climate change on the distribution pattern of Paralaudakia lehmanni in Central Asia. According to the results, the current distribution is predicted from North Afghanistan, Tajikistan, and Kyrgyzstan and the precipitation of coldest quarter (BIO19) was the most contributed bioclimate variable. Future predictions show a similar pattern with the current period and, based on the niche overlap test, the overlap of these patterns was more than 0.85 and indicated no differences between them. Distribution can be affected by the highland distribution of P. lehmanni. Because this species has such an elevated range, precipitation of coldest quarter is not predicted to change much in future and therefore suitable habitats will remain similar to current period. Finally, although there is no predicted impact of climate change on the species distribution pattern in future, the conservation of P. lehmanni is important because of other threats such as human disturbance and predation.     

Potential impact of climate change on the distribution and conservation status of Pterocarpus marsupium,a Near Threatened South Asian medicinal tree species

Climate change is considered as an important environmental issue globally, affecting geographic distributions of endangered species, and reducing the extent of their natural habitats. We characterized the potential geographic distribution of a Near Threatened tree species, Pterocarpus marsupium, in South Asia. We evaluated the potential geographic distribution of the species under present and future conditions using ecological niche modeling approaches. The future potential distribution of the species was examined under two representative concentration pathway scenarios (RCP 4.5 and 8.5), using outputs from 8 general circulation models for 2050. The present-day distribution of the species covers much of India and Sri Lanka, and parts of Nepal and Bhutan. Model transfers for future-climate conditions indicated a potentially dramatic geographic shift of high-suitability areas for parts of the species' distribution, particularly in central India. In distributional areas that are adjacent to high-mountain areas, under climate change, suitable areas for the species are anticipated to shift towards higher elevations. The results of this study may be useful in identifying currently undocumented populations of P. marsupium, as well as in identifying sites likely to be suitable both at present and in the future for conservation management planning.     

伯乐树潜在地理分布时空格局模拟

以伯乐树(Bretschneidera sinensis Hemsl.)为研究对象,基于现有的151个伯乐树居群分布点及12个气候变量,运用MaxEnt模型和GIS技术,模拟末次盛冰期、全新世中期、当前、未来(RCP 2.6、RCP 4.5、RCP 6.0和RCP 8.5)气候情景下的伯乐树潜在地理分布格局;采用受试者工作特征曲线(ROC)下的面积(AUC值),评价模拟的精度;综合分析测试增益、气候变量贡献率及置换重要值,探讨制约伯乐树地理分布的主导气候变量;基于分布面积比(N a)、生境变化程度(N e),比较伯乐树在不同气候情景下的地理分布动态。ROC曲线结果显示,7种不同气候情景下的训练集与测试集AUC值均大于0.99,表明模型模拟精度极高。测试增益、气候变量贡献率及置换重要值显示,昼夜温差月均值、等温性和最干季度降水量是伯乐树潜在地理分布的限制因子。不同气候情景下伯乐树地理分布动态暗示,金佛山、大瑶山可能是伯乐树冰期多个微型避难所;末次盛冰期以来,伯乐树地理分布经历了扩张过程;未来不同气候情景下,其地理分布范围可能会发生不同程度(25%~47%)的收缩,其中RCP 8.5情境下,伯乐树居群生境破碎化最为严重。开展伯乐树资源调查、收集和遗传管理的国际合作,在气候适宜地区建立迁地保育林,是有效防止伯乐树遗传资源丢失的重要措施。     

基于青冈和滇青冈生态位模拟的湿润和半湿润常绿阔叶林替代分布及气候解释

为揭示湿润常绿阔叶林和半湿润常绿阔叶林替代分布的气候制约变量,该研究选择其代表性优势树种青冈(Cyclobalanopsis glauca)和滇青冈(C.glaucoides)为研究对象,收集两个物种的标本分布点数据和19个生物气候变量图层数据,运用MaxEnt模型,模拟其潜在分布区,通过判别分析(DFA)、方差分析(...     

基于生态位模型的外来入侵种克氏原螯虾在中国的适生区预测

克氏原螯虾在20世纪初作为重要的水产品引入中国,但因其繁殖能力强、生长迅速、适应性强、喜掘洞穴,对农作物、池埂及农田水利有一定破坏作用,降低入侵地区当地物种多样性,对当地生态系统造成严重危害。因此,研究未来气候情景下克氏原螯虾适生区的变化,可为其监控和管理措施提供关键信息,有效预防和控制其蔓延。本研究基于克氏原螯虾的分布点,应用最大熵(MaxEnt)模型和规则集遗传算法(GARP)模型模拟了当前气候条件下克氏原螯虾在中国的潜在适生区,并预测了2041—2060年和2061—2080年克氏原螯虾在4种气候变化情景下(RCP 2.6、RCP 4.5、RCP 6.0、RCP 8.5)的分布,采用ROC曲线对预测结果进行检验和评价。结果表明: 在当前气候条件下克氏原螯虾集中分布在上海、江苏、浙江、安徽等长江沿岸地区;最冷季平均温度、最冷月最低温度对克氏原螯虾分布影响最大,其次是温度季节性变化、最暖月最高温度和最干月降水量。在未来气候情景下,2061—2080年克氏原螯虾的适生区面积有不同程度的变化,在RCP 2.6和RCP 4.5情景下总适生面积增加,但在RCP 8.5情景下呈先增后减趋势,而在RCP 6.0情景下无明显变化;克氏原螯虾适生区在空间分布上不仅有纬度方向上的扩散,也有向海拔较高地区迁移的趋势。     

Shifts in Climate Foster Exceptional Opportunities for Species Radiation: The Case of South African Geraniums

Climate change is often assumed to be a major driver of biodiversity loss. However, it can also set the stage for novel diversification in lineages with the evolutionary ability to colonize new environments. Here we tested if the extraordinary evolutionary success of the genus Pelargonium was related to the ability of its species to capitalize on the climate niche variation produced by the historical changes in southern Africa. We evaluated the relationship between rates of climate niche evolution and diversification rates in the main Pelargonium lineages and disentangled the roles of deep and recent historical events in the modification of species niches. Pelargonium clades exhibiting higher ecological differentiation along summer precipitation (SPP) gradients also experienced higher diversification rates. Faster rates of niche differentiation in spatially structured variables, along with lower levels of niche overlap among closely related species, suggest recent modification in species niches (e.g. dispersal or range shift) and niche lability. We suggest that highly structured SPP gradients established during the aridification process within southern Africa, in concert with niche lability and low niche overlap, contributed to species divergence. These factors are likely to be responsible for the extensive diversification of other lineages in this diversity hot spot.     

Using MaxEnt modeling to predict the potential distribution of the endemic plant Rosa arabica Crép. in Egypt

Climate change poses negative impacts on plant species, particularly for those of restricted ecology and distribution range. Rosa arabica Crép., an exclusive endemic species to Saint Catherine Protectorate in Egypt, has severely declined and become critically endangered in the last years. In this paper, we applied the maximum-entropy algorithm (MaxEnt) to predict the current and future potential distribution of this species in order to provide a basis for its protection and conservation. In total, 32 field-based occurrence points and 22 environmental variables (19 bioclimatic and three topographic) were used to model the potential distribution area under current and two future representative concentration pathways (RCP2.6 and RCP8.5) for the years 2050 and 2070. Annual temperature, annual precipitation and elevation were the key factors for the distribution of R. arabica. The response curves showed that this species prefers habitats with an annual temperature of 8.05–15.4 °C, annual precipitation of 36 to 120 mm and elevation range of 1571 to 2273 m a.s.l. Most of the potential current suitable conditions were located at the middle northern region of Saint Catherine. Prediction models under two future climate change scenarios displayed habitat range shifts through the disappearance of R. arabica in sites below 1500 m a.s.l., an altitudinal range contraction at 1500–2000 m and possible expansions towards higher elevation sites (2000–2500 m a.s.l.). Our findings can be used to define the high priority areas for reintroduction or for protection against the expected climate change impacts and future modifications.