Forecasting cloud forest in eastern and southern Mexico: conservation insights under future climate change scenarios

Assuming that co-distributed species are exposed to similar environmental conditions, ecological niche models (ENMs) of cloud forest species were developed to study how climate change could affect the distribution of cloud forest in eastern and southern Mexico for the year 2050. Using ENM-based predictions and climatic data for IPCC climate change A2 and B2 scenarios, we observed 54–76% reduction of the cloud forest, mainly in the northern region of its current range (Sierra Madre Oriental) and the Pacific slope of Chiapas. With predicted 2050 climate change, cloud forest in the Los Tuxtlas region and El Cielo Biosphere Reserve may face a serious threat of extinction due to the observed upward migration to higher elevations. Our results add to recent studies detecting negative impacts of climate change in montane forests, but the negative impacts of climate change might be exacerbated by current environmental changes in the region. The integration of ecological-niche characteristics of cloud forest in conjunction with projections of extreme climate scenarios constitute a suitable tool to define appropriate areas in which proactive conservation and management strategies should be focused.     

Austral Yungas under future climate and land-use changes scenarios: the importance of protected areas for long-term amphibian conservation

Biodiversity and Conservation - We estimated the potential distribution for 31 amphibian species inhabiting the threatened Austral Yungas under current and future climate projections (2050’s)...     

Backwater habitats and their role in nature conservation on navigable waterways

In Britain, lightly trafficked canals frequently contain diverse, productive macrophyte communities. These represent important habitats for macroinvertebrates and fish while having a high intrinsic value in nature conservation terms. As recreational boat traffic increases, fragile macrophytes are progressively eliminated and the biomass of the remaining species is greatly reduced, thereby adversely affecting weed-associated animals and ultimately simplifying the structure of the whole ecosystem. From the viewpoint of aesthetics, nature conservation and fisheries management,ecological enhancement of these traffic impacted ecosystems is desirable but options are limited by channel size and the intensity and type of disturbance. Backwater areas connected to the main channel but apparently remote from traffic influences ought however, to provide a minimally-disturbed refuge for macrophytes and dependent organisms. An extensive field survey was undertaken to test this hypothesis and evaluate the potential for exploiting backwater sites as off-line nature reserves. Principal determinants of vegetation structure and species diversity are identified and discussed and are used to prescribe a set of ideal characteristics for prospective backwater nature reserves and to forecast likely management problems.     

气候变化背景下青藏高原藏羚羊生境时空格局演变

气候变化可能导致物种分布范围变化甚至导致物种灭绝。为了解气候变化对青藏高原旗舰种和濒危种-藏羚羊（Pantholops hodgsonii）的潜在分布区影响,收集了316个藏羚羊实际点位分布数据和70个文献点位分布数据与温度季节性变化（Bio4）,海拔,最干月降雨（Bio14）等9个影响因子,采用最大熵模型（MaxEnt）进行建模,预测SSP126、SSP585极端压迫情景和SSP245中间压迫情景下的T1（2001-2018年）,T2（2021-2040年）,T3（2041-2060年）,T4（2061-2080年）,T5（2081-2100年）5个时期的潜在分布区。研究结果表明：（1）在不同气候变化情景下,藏羚羊核心生境主要分布在可可西里、羌塘、阿尔金国家级自然保护区和三江源国家公园;（2）温度季节性变化（Bio4）和海拔被认为是最关键的两个环境因子;（3）随着温室气体排放强度的增强,藏羚羊的核心区生境向高海拔和高纬度地区扩张;（4）有43.18%的保护空缺区在保护区外,未受到有效保护。总之,研究藏羚羊的地理分布对于气候变化的响应与适应,根据适宜生境演变规律做出有效的保护措施,对藏羚羊种群的长期监测、保护、有效管理甚至重建具有重要现实意义。     

African lakes and their fishes: conservation scenarios and suggestions

Synopsis Man has been associated with a variety of lakes throughout his evolutionary history in Africa. Lakeside dwellers have a close association with and understanding of these lakes. In the past four decades, however, overexploitation, introductions of alien fishes and the possibility of oil pollution present frightening prospects of irreversible losses and massive extinction. The development of scientific understanding of the life support processes, the ecosystems and the rich communities of these lakes has been so outpaced by exploitation and manipulations that accurate predictions regarding the future are impossible. Shallow lakes are more sensitive to physico-chemical changes caused by climatic as well as agricultural and industrial development than deep lakes, but their biotae are endowed with a resilience which facilitates recovery from major depletions to population size. In contrast, the speciose endemic cichlid faunae of deep lakes are sensitive to fishing pressure, are awkward to manage and should be regarded as representing a much smaller resource than initially imagined. The clupeids of Lake Tanganyika can sustain intensive fishing, but their introduction into other natural lakes is not recommended. Enormous changes to native faunae followed the introduction of Lates niloticus to lakes Kyoga and Victoria with dramatic consequences for the fisheries, for the socio-economic status of the region and for the maintenance of biotic diversity. Extinction of almost 300 fish species is a possible further consequence of L. niloticus predation. Intensive selective fishing for L. niloticus is being initiated, but is unlikely to resolve the problem. In the time necessary to substantially reduce L. niloticus, numerous endemic fishes may suffer extinction. A viable alternative to extinction of these species is captive propagation. Conservation of fishes by captive propagation is not a common or well documented practice. To encourage the acceptance of this conservation option a theoretical scenario in which the concepts and protocols are applied to the fishes of Lake Victoria is given. The possibility of returning rescued populations to the lake at a later date, assuming L. niloticus populations have been reduced, is also discussed. It is recommended that captive propagation should be practised to conserve species and to retain the option of returning rescued taxa. Scientists are urged to seek the funding to study tropical ecosystems so that conservation and rational development may acquire a sound foundation.     

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.     

气候变化对四合木适生区及空间迁移的影响

四合木(Tetraena mongolica )是中国特有的孑遗种植物,被誉为植物中的"大熊猫",由于早期过度放牧、滥垦乱伐等人为因素,使这一物种一度濒临灭绝。预测气候变化对分布范围的影响可为四合木的野生资源保存与可持续利用提供科学基础和参考依据。利用27个地理分布点和从Worldclim网站下载的18个环境因子数据,基于优化后的MaxEnt模型预测四合木在中国的地理分布格局和限制其分布的主导环境因子。结果表明,通过调用R平台ENMeaval程序包进行模型优化,最终确定FC=LQHPT,RM=4,优化参数后的模型精度优于默认参数下的模型精度。优化后的MaxEnt模型预测测试数据集和训练数据集AUC值均在0.98以上;现代四合木潜在地理分布的总的适生区面积约为124.45×104 km²,高适生区面积约为3.35×104 km²,高适生区主要集中于内蒙古阿拉善左旗、鄂托克旗以北,黄河上游达拉特旗以南,乌海市、巴彦淖尔市以东,鄂尔多斯市以西;宁夏回族自治区北部石嘴山市及贺兰山北麓也有少量分布。最干月降水量(36.95%)、年降水量(14.83%)、表层土壤有机碳含量(11.21%)、海拔(9.38%)、最干季度平均气温(6.28%)、年均温(5.49%)、人类活动因子(3.10%)、表层土砾石含量(3.01%)、等温性(2.44%)、表层土壤碳酸盐或石灰含量(2.32%)、表层土壤酸碱度(2.02%)和最冷月最低气温(1.32%)是影响四合木分布的主要环境因子。分析发现,随着气候暖化,四合木新增适生面积将会逐步缩减,现代潜在高适生区可能依然是其未来的避难所,其分布重心可能将会向东迁移。本研究为进一步明确四合木适宜栖息地在中国的地理分布格局和制定有效的保护策略提供了科学参考。     

The future impact of climate and land-use changes on Anatolian ground squirrels under different scenarios

Climate and land-use changes are among the most important drivers of biodiversity loss and, moreover, their impacts on biodiversity are expected to increase further in the 21st century. In this study, the future impact of climate and land-use changes on Anatolian ground squirrels (Spermophilus xanthoprymnus) was assessed. Accordingly, a hierarchical approach with two steps was used. First, ecological niche modelling was used to assess the impact of climate change in areas accessible to Anatolian ground squirrels through dispersal (i.e. the impact of climate change). Second, based on the habitat preferences of ground squirrels, land-use data were used to assess the impact of land-use change in suitable bioclimatic areas for Anatolian ground squirrels under present and future conditions (i.e. the combined impact of both changes). Also, priority areas for the conservation of Anatolian ground squirrels were identified based on in-situ climate change refugia. This study represents a first attempt to combine niche modelling and land-use data for a species in Anatolia, one of the most vulnerable regions to the drivers of biodiversity loss, because it is the region where three of biodiversity hotspots meet, and interact. Habitat suitability (i.e. suitable habitats across suitable bioclimatic areas) was projected to decline by 19–69% in the future (depending on the scenario), mainly due to the loss of suitable bioclimatic areas (47–77%, depending on the scenario) at lower elevations and in the western part of the central Anatolia and in the eastern Anatolia, suggesting that Anatolian ground squirrels will contract their range in the future, mainly due to climate change. Thus, in-situ climate change refugia were projected mainly in the eastern and southeastern parts of the central Anatolia, suggesting these regions as priority areas for the conservation of Anatolian ground squirrels.     

Spatial evaluation of switchgrass productivity under historical and future climate scenarios in Michigan

Switchgrass (Panicum virgatum) productivity on marginal and fertile lands has not been thoroughly evaluated in a systematic manner that includes soil–crop–weather–management interactions and to quantify the risk of failure or success in growing the crop. We used the Systems Approach to Land Use Sustainability (SALUS) model to identify areas with low risk of failing to having more than 8000 kg ha^?1 yr^?1 switchgrass aboveground net primary productivity (ANPP) under rainfed and unfertilized conditions. In addition, we diagnosed constraining factors for switchgrass growth, and tested the effect of nitrogen fertilizer application on plant productivity across Michigan for 30 years under three climate scenarios (baseline climate in 1981–2010, future climate with emissions using RCP 2.6 and RCP 6.0). We determined that <16% of land in Michigan may have at least 8 Mg ha^?1 yr^?1 ANPP under rainfed and unfertilized management with a low risk of failure. Of the productive low‐risk land, about 25% was marginal land, with more than 80% of which was affected by limited water availability due to low soil water‐holding capacity and shallow depth. About 80% of the marginal land was N limited under baseline conditions, but that percentage decreased to 58.5% and 42.1% under RCP 2.6 and RCP 6.0 climate scenarios, respectively, partly due to shorter growing season, smaller plants and less N demand. We also found that the majority of Michigan's land could have high switchgrass ANPP and low risk of failure with no more than 60 kgN ha^?1 fertilizer input. We believe that the methodology used in this study works at different spatial scales, as well as for other biofuel crops.     

Surfing parameter hyperspaces under climate change scenarios to design future rice ideotypes

Growing food crops to meet global demand and the search for more sustainable cropping systems are increasing the need for new cultivars in key production areas. This study presents the identification of rice traits putatively producing the largest yield benefits in five areas that markedly differ in terms of environmental conditions in the Philippines, India, China, Japan and Italy. The ecophysiological model WARM and sensitivity analysis techniques were used to evaluate phenotypic traits involved with light interception, photosynthetic efficiency, tolerance to abiotic stressors, resistance to fungal pathogens and grain quality. The analysis involved only model parameters that have a close relationship with phenotypic traits breeders are working on, to increase the in vivo feasibility of selected ideotypes. Current climate and future projections were considered, in the light of the resources required by breeding programs and of the role of weather variables in the identification of promising traits. Results suggest that breeding for traits involved with disease resistance, and tolerance to cold‐ and heat‐induced spikelet sterility could provide benefits similar to those obtained from the improvement of traits involved with canopy structure and photosynthetic efficiency. In contrast, potential benefits deriving from improved grain quality traits are restricted by weather variability and markedly affected by G × E interactions. For this reason, district‐specific ideotypes were identified using a new index accounting for both their productivity and feasibility.     

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.     

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。     

Modelling the climate suitability of green carpenter bee (Xylocopa aerata) and its nesting hosts under current and future scenarios to guide conservation efforts

Due to local extinction, the endangered green carpenter bee (Xylocopa aerata) has a disjunct distribution in the southeast of Australia. The species relies on dead softwood from a small selection of plant species for making its nests. Habitat fragmentation, combined with deleterious fire events, is thought to have negatively impacted on nesting substrate availability and recolonisation chances. Here, we use MaxEnt algorithm to model both the current distribution and the effect of climate change scenarios on the distribution of both X. aerata and four plant species that provide most of its nesting substrate: Banksia integrifolia, B. marginata, Xanthorrhoea arborea and Xanthorrhoea semiplana subsp. tateana. The annual mean temperature is the strongest climatic predictor of the distribution of X. aerata and its host plants. The modelled distribution of the bee under current climatic conditions indicates that climatic factors are unlikely to cause local extinctions. In all future scenarios, suitable areas for X. aerata and each of its nesting hosts are expected to contract towards the southeast of mainland Australia. The suitability of Kangaroo Island for the bee and its current local current host species is maintained in all scenarios, while Tasmania will become increasingly suitable for all species. The Grampians National Park in western Victoria, where the bee species were last seen outside of its current range (in the 1930s), is predicted to remain suitable for X. aerata and several host plants under all scenarios. Therefore, this relatively large area of native vegetation may be a good case study for re‐introduction as part of future conservation efforts.     

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.     

Biodiversity of moderately halophilic bacteria in hypersaline habitats in Egypt

Screening bacteria from different saline environments in Alexandria. Egypt, lead to the isolation of 76 Gram-negative and 14 Gram-positive moderately halophilic bacteria. The isolates were characterized taxonomically for a total of 155 features. These results were analyzed by numerical techniques using simple matching coefficient (SSM) and the clustering was achieved by the unweighed pair-group method of association (UPGMA). At 75% similarity level the Gram-negative bacteria were clustered in 7 phena in addition to one single isolate, whereas 4 phena represented the Gram-positive. Based on phenotypic characteristics, it is suggested that the Gram-negative bacteria belong to the genera Pseudoalteromonas, Flavobacterium, Chromohalobacter, Halomonas and Salegentibacter, in addition to the non-identified single isolate. The Gram-positive bacteria are proposed to belong to the genera Halobacillus, Salinicoccus, Staphylococcus and Tetragenococcus. This study provides the first publication on the biodiversity of moderately halophilic bacteria in saline environments in Alexandria, Egypt.     

Expected future plague levels in a wildlife host under different scenarios of climate change

We predicted future plague and black-tailed prairie dog dynamics in the North American prairies under different scenarios of climate change. A climate-driven model for the joint dynamic of the host–parasite system was used. Projections for the regional climate were obtained through empirical–statistical downscaling of global climate scenarios generated by an ensemble of global climate models for the recent Fourth Assessment Report by the IPCC. The study shows the uncertainties involved in predicting future regional climate and climate-driven population dynamics, but reveals that unchanged or lower levels of plague, leading to increased black-tailed prairie dog colonies, can be expected. Less plague is particularly expected for scenarios that assume the highest emission of greenhouse gases associated with the greatest projected future warming. Moreover, under high-emission scenarios, decreased probabilities of extremely high numbers of infected colonies are expected, along with decreased probabilities of extremely low total numbers of colonies. The assumed main underlying mechanism is an inhibiting effect of high temperatures on fleas (dispersal vector) and on flea-mediated transmission of the disease-causing bacterium. Our study highlights the importance of using dynamic ecological (here host–parasite) models together with ensembles of climate projections to investigate the responses of populations and parasites to a changed climate.