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。     

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。     

气候变化对孑遗植物银杉的潜在分布及生境破碎度的影响

以孑遗植物银杉(Cathaya argyrophylla Chun et Kuang)为研究对象,选取65个地理分布记录和19个生物气候因子(bio1—bio19),利用MaxEnt模型预测四种不同浓度路径下(RCP 2.6、RCP 4.5、RCP 6.0和RCP 8.5),银杉在2050s和2070s两个年代的潜在分布变化,并利用景观指数对气候变化情景下银杉适宜生境空间格局特征转变及生境破碎度变化进行分析。结果表明:在当前气候情景下,银杉适宜生境面积约占研究区面积的14.32%,主要分布于北纬24°—32°、东经105°—114°之间,位于四川盆地东南地区、云贵高原东北地区、南岭西段地区以及浙闽丘陵的北部地区。在未来不同气候情景下,银杉适宜生境变化特征显著,面积呈增加趋势,形状上整体呈四周向中间聚集。气候变化对银杉适宜生境的景观指数影响主要表现在斑块数量增多、斑块密度增加、面积加权平均形状指数变大,对分离度与聚散性影响较小;气候变化对银杉生境破碎化程度的影响表现在破碎化两极现象减弱,总体破碎化程度加剧。研究选取7个景观指数并结合PCA法得到综合的破碎度指数来定量分析银杉适宜生境破碎化程度变化,相比单一指标的定量评价和多个指标的定性分析,更能代表银杉生境的实际破碎化程度。     

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.     

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.     

Tracing the future of epidemics: Coincident niche distribution of host animals and disease incidence revealed climate-correlated risk shifts of main zoonotic diseases in China

Climate has critical roles in the origin, pathogenesis and transmission of infectious zoonotic diseases. However, large-scale epidemiologic trend and specific response pattern of zoonotic diseases under future climate scenarios are poorly understood. Here, we projected the distribution shifts of transmission risks of main zoonotic diseases under climate change in China. First, we shaped the global habitat distribution of main host animals for three representative zoonotic diseases (2, 6, and 12 hosts for dengue, hemorrhagic fever, and plague, respectively) with 253,049 occurrence records using maximum entropy (Maxent) modeling. Meanwhile, we predicted the risk distribution of the above three diseases with 197,098 disease incidence records from 2004 to 2017 in China using an integrated Maxent modeling approach. The comparative analysis showed that there exist highly coincident niche distributions between habitat distribution of hosts and risk distribution of diseases, indicating that the integrated Maxent modeling is accurate and effective for predicting the potential risk of zoonotic diseases. On this basis, we further projected the current and future transmission risks of 11 main zoonotic diseases under four representative concentration pathways (RCPs) (RCP2.6, RCP4.5, RCP6.0, and RCP8.5) in 2050 and 2070 in China using the above integrated Maxent modeling with 1,001,416 disease incidence records. We found that Central China, Southeast China, and South China are concentrated regions with high transmission risks for main zoonotic diseases. More specifically, zoonotic diseases had diverse shift patterns of transmission risks including increase, decrease, and unstable. Further correlation analysis indicated that these patterns of shifts were highly correlated with global warming and precipitation increase. Our results revealed how specific zoonotic diseases respond in a changing climate, thereby calling for effective administration and prevention strategies. Furthermore, these results will shed light on guiding future epidemiologic prediction of emerging infectious diseases under global climate change.     

Predicted declines in suitable habitat for greater one‐horned rhinoceros (Rhinoceros unicornis) under future climate and land use change scenarios

Rapidly changing climate is likely to modify the spatial distribution of both flora and fauna. Land use change continues to alter the availability and quality of habitat and further intensifies the effects of climate change on wildlife species. We used an ensemble modeling approach to predict changes in habitat suitability for an iconic wildlife species, greater one‐horned rhinoceros due to the combined effects of climate and land use changes. We compiled an extensive database on current rhinoceros distribution and selected nine ecologically meaningful environmental variables for developing ensemble models of habitat suitability using ten different species distribution modeling algorithms in the BIOMOD2 R package; and we did this under current climatic conditions and then projected them onto two possible climate change scenarios (SSP1‐2.6 and SSP5‐8.5) and two different time frames (2050 and 2070). Out of ten algorithms, random forest performed the best, and five environmental variables—distance from grasslands, mean temperature of driest quarter, distance from wetlands, annual precipitation, and slope, contributed the most in the model. The ensemble model estimated the current suitable habitat of rhinoceros to be 2610 km², about 1.77% of the total area of Nepal. The future habitat suitability under the lowest and highest emission scenarios was estimated to be: (1) 2325 and 1904 km² in 2050; and (2) 2287 and 1686 km² in 2070, respectively. Our results suggest that over one‐third of the current rhinoceros habitat would become unsuitable within a period of 50 years, with the predicted declines being influenced to a greater degree by climatic changes than land use changes. We have recommended several measures to moderate these impacts, including relocation of the proposed Nijgad International Airport given that a considerable portion of potential rhinoceros habitat will be lost if the airport is constructed on the currently proposed site.     

中国西南地区土地覆盖情景的时空模拟

气候植被类型的空间分布与土地覆盖类型的空间分布在时空层次上具有很好的相关性和一致性。在运用HLZ生态系统模型获得CMIP5的3种气候情景RCP26、RCP45、RCP85情景下西南地区未来90a(2011—2100年)HLZ生态系统时空分布情景数据的基础上,结合2010年土地覆盖现状数据,构建了土地覆盖情景的空间分析模型,并在此基础上,实现了西南地区未来90a土地覆盖情景的时空模拟分析。模拟结果表明:3种气候情景下,西南地区未来90a的落叶针叶林、落叶阔叶林、草地、耕地、冰雪、荒漠及裸岩石砾地等土地覆盖类型面积将呈逐渐减少趋势;常绿针叶林、常绿阔叶林、混交林、灌丛、湿地、建设用地、水体等土地覆盖类型面积则呈逐渐增加趋势。其中,湿地增加速度最快(平均每10a增加5.28%),荒漠及裸岩石砾地减少速度最快(平均每10a减少2.34%)。     

全球气候变化下贵州省青冈林的潜在生境动态

为了解贵州省青冈林在全球气候变化下的潜在分布特征,基于现状分布数据,结合当前气候数据和未来气候变化情景(RCP8.5情景,2070-2099年)构建Maxent潜在分布模型,预测贵州省青冈林的潜在分布变化。结果表明,最冷季均温(bio11)、最冷月最低温度(bio6)和年均降水量(bio12)为控制贵州省青冈林潜在生境的主导气候因子;RCP8.5情景下贵州省青冈林的潜在分布面积相较当前气候条件增加,中度适宜生境增加19 419 km2,高度适宜生境增加9 944 km2;中度适宜生境平均海拔较当前气候条件上升126 m,高度适宜生境平均上升85 m。总的来说,贵州省青冈林对全球气候变化的响应不十分敏感。     

未来气候变化对孑遗植物鹅掌楸地理分布的影响

为了解未来气候波动对鹅掌楸(Liriodendron chinense)潜在适生区的影响,利用最大熵模型(Maxent)和地理信息系统(ArcGIS)软件,结合物种地理分布点信息,对鹅掌楸当前适生区分布进行了模拟和划分,同时预测了2061-2080年间气候变化条件下鹅掌楸的潜在适生分布区变化,进而分析影响鹅掌楸地理分布...     

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.     

气候变化情景下基于最大熵模型的中国西南地区清香木潜在分布格局模拟

清香木(Pistacia weinmannifolia)是中国西南干旱河谷植被的特征种。本文利用野外调查的165个清香木分布点信息以及22个环境变量数据, 基于最大熵(Maxent)算法构建清香木分布的适宜生境预测模型, 并据此模拟清香木在我国西南地区的适宜分布区, 以及历史和未来不同气候情景下的分布格局变化。结果表明: 清香木生境预测的Maxent模型准确性非常高(AUC = 0.974), 温度季节性变化、极端低温和降水量是限制其分布的主要气候因子。清香木当前的潜在分布区集中在我国西南干旱河谷区, 其适宜生境的气候特征是降水少、温度季节性变化小且无极端低温。对清香木在末次间冰期和末次冰盛期分布的模拟结果表明, 其分布区范围均以诸大江河的河谷为中心, 随气候变化在我国西南地区主要呈现先向东扩张, 然后向西退缩的趋势, 并印证了“冰期走出横断山(glacial out-of-Hengduan Mts.)”的观点。在未来(2061-2080年) 3种典型浓度路径(representative concentration pathway, RCP)的气候情景下, 清香木在我国西南地区的分布都向东扩张, 主要分布在云贵高原与四川盆地结合地带的河谷, 以及云贵高原与广西西部交界地带的河谷中, 这也反映了这些地区河谷地段干旱化的可能, 而当前的潜在分布区趋于消失; 清香木的潜在适宜分布面积在中低浓度路径情景下均将减少约33%, 而在高浓度路径情景下有所增加。     

气候变化情景下大花杓兰在中国的适生区预测

大花杓兰(Cypripedium macranthos)隶属兰科杓兰属,是国家二级重点保护野生植物,与大多数杓兰属植物分布在我国西南山区不同,主要分布于我国的华北、东北和台湾等地区。多年来,过渡采挖等导致了大花杓兰种群数量和个体数目急剧下降。鉴于大花杓兰特殊的分布格局和濒危现状,选择过去、当前和未来8个气候情景,利用MaxEnt物种分布模型结合38个环境变量及来源于数据库和最新实地调查的80个分布位点进行建模,分析了影响大花杓兰分布的关键环境变量,预测了其在当前、过去和未来气候情景下的适生区及其分布中心和迁移趋势。结果表明：当前情景下,大花杓兰适生区主要分布在我国东北和华北地区。影响其分布的5个关键环境变量分别是：UV-B最强月份均值(UV-B3,贡献率：54.0%)、森林覆盖率(FOR,贡献率：14.3%)、降水量季节性变化(BIO15,贡献率：7.4%)、温度季节性变动系数(BIO4,贡献率：6.8%)和草/灌木/林地(GRS,贡献率：4.6%)。其中,紫外辐射相关变量是首次被运用在杓兰属植物的适生区分布预测中,并被证实对大花杓兰的分布具有重要影响。过去3个气候情景下大花杓兰总适生...     

多气候情景下中国森林火灾风险评估

森林火灾风险主要取决于致灾因子、承灾体以及防灾减灾能力,综合评估和预测森林火灾风险是制定科学的林火管理政策的基础.本文基于经典自然灾害风险模型和可获取数据构建森林火灾风险评估模型与指标体系,评估过去和未来的森林火灾风险.未来气候情景数据包括RCP 2.6、RCP 4.5、RCP 6.0和RCP 8.5下5个全球气候模式(GFDL-ESM2M、HadGEM2-ES、IPSL-CM5A-LR、 MIROC-ESM-CHEM和NorESM1-M)日值数据.根据最高温度、最小相对湿度、平均风速和每日降水量分别计算1987—2050年历史观测数据和未来气候情景下各格点每日火险天气指数系统中各个指数.结果表明: 1987—2010年,森林火灾风险高和很高的区域分别占21.2%和6.2%,主要分布在大兴安岭和长白山地区、云南大部分区域和南方零散分布的区域.森林火灾可能性高和很高的区域主要分布在东北和西南地区,分别占森林面积的13.1%和4.0%.与观测时段相比,2021—2050年RCP 2.6、RCP 4.5、RCP 6.0和RCP 8.5情景下森林火灾可能性高和很高的区域分别增加0.6%、5.5%、2.3%和3.5%,华北地区增幅明显.气候变化引起的森林火灾高风险区域有些增加,RCP 8.5情景下增幅最明显(+1.6%).     

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。     

北重楼潜在适生区对气候变化的响应及其主导气候因子

基于现有物种数据结合气候变量来预测物种的潜在地理分布,对于了解物种进化以及合理保护具有重要意义。本研究基于中国境内220个北重楼分布点和12个相关系数较低的气候因子,利用MaxEnt模型和ArcGIS软件预测了北重楼在当前时期和未来时期(2050s、2070s)的潜在适生区,并分析了影响其地理分布的主导气候因子。结果表明: MaxEnt模型AUC值为0.940,预测结果准确性较高;当前时期,北重楼的总适生区面积占整个研究区域面积的18.1%,其中,高适生区和低适生区分别占7.0%和11.1%,主要位于大兴安岭、小兴安岭、长白山山脉、秦岭-大巴山区、河北、山西以及山东北部等地区;未来时期在RCP 2.6、RCP 4.5、RCP 6.0、RCP 8.5气候情景下,2050s和2070s中国境内北重楼的总适生区面积均呈现缩减趋势,其中,高适生区面积均减少,而低适生区面积则全部有所增加,且北重楼适生区的范围和几何中心逐渐向东北方向的高海拔地区扩散;影响北重楼地理分布的主导气候因子分别为最湿月降水量、年平均温度、等温性和1月降水量,累积贡献率高达89.2%,其适宜范围分别为100～275 mm、-0.1～16 ℃、21～35和3～14 mm。     

气候变化对东北濒危动物驼鹿潜在生境的影响

气候变化是造成生物多样性下降和物种灭绝的主要因素之一。研究气候变化对物种生境,尤其是濒危物种生境影响对未来保护物种多样性和保持生态系统功能完整性具有重要意义。以驼鹿乌苏里亚种(Alces alces cameloides)为研究对象,选取了对驼鹿分布可能存在影响的22个环境因子,利用最大熵(Maxent)模型模拟了驼鹿基准气候条件下在我国东北的潜在生境分布,并预测了RCP4.5和RCP8.5两种气候变化情景下2041—2060年(2050s)、2061—2080年(2070s)驼鹿潜在分布,采用接收工作曲线下面积(AUC)对模型预测能力进行评估。研究结果表明:最大熵模型预测驼鹿潜在生境分布的精度较高(平均AUC值为0.845),22个环境因子中,年均温、最暖季均温、年降水、平均日较差是影响驼鹿生境分布的主要因子。基准气候条件下,驼鹿的潜在生境面积占研究区域总面积的36.4%,潜在生境分布区主要在大、小兴安岭。随着时间的推移,研究区内驼鹿当前潜在生境面积明显减少,而新增潜在生境面积较少,总面积呈现急剧减少的趋势,其中RCP8.5情景减少程度大于RCP4.5情景。至2050s阶段,当前潜在生境面积平均将减少62.3%,新增潜在分布面积平均仅为3.6%,总潜在生境面积最高将减少65.6%,平均将减少58.8%;至2070s阶段,当前潜在生境面积平均将减少75.8%,新增潜在分布面积平均仅为1.9%,总潜在生境面积最高将减少93.1%,平均减少73.9%。空间分布上,驼鹿的潜在生境的几何中心将先向西北移动,然后再向高纬度地区西南方向迁移,至2050s阶段,潜在分布生境的几何中心在RCP4.5和RCP8.5情景下的迁移距离分别为183.5 km和210.8 km;至2070s阶段,相应情景下的迁移距离将缩短至28.7 km和33.8 km。潜在生境分布整体呈现向高海拔、高纬度迁移的趋势。     

Distribution Changes of Chinese Skink(Eumeces chinensis) in China: the Impacts of Global Climate Change

Repaid global climate changes in temperature and rainfall influence the species distribution and diversity patterns. Chinse skink is a common species with large population and widely distribution in China. To access potential effect of climate changes on the unendangered species, we used the maximum-entropy modeling(MaxEnt) method to estimate the current and future potential distributions of Chinese Skink. Predictions were based on two periods(2050 and 2070), three general circulation models(GCMs: BCC-CSM1-1, HadGEM2-ES, MIROC5),four representative concentration pathways(RCP:2.6, 4.5, 6.0 and 8.0) and 28 environmental variables including topography, human impact, bio-climate and habitat. We found that the model were better fit with high values in AUC, KAPPA and TSS. The jackknife tests showed that variables of BIO9, BIO14, BIO15, HFI and GDP were relatively higher contributions to the model. Although the size of suitable areas for skink have less effect by future climate change under full and mull dispersal hypothesis, we should still focuse on the effect of human impact and climate changes on the protection and management for Chinese skink due to the variables uncertainty.     

气候变化对中国近海8种中上层鱼类潜在生境分布的影响

随着底层和近底层渔业资源的衰退,海洋中上层鱼类在我国海洋捕捞业中逐渐占据重要的地位。预测气候变化情景下中上层经济鱼类的潜在生境分布及其变化规律,可为应对气候变化的鱼类栖息地保护和渔业生态系统管理提供重要科学依据。采用物种分布模型模拟并预测现状及2050年两种气候变化情景下8种中上层经济鱼类在中国近海的潜在分布,通过分布区的收缩-扩张情形和质心迁移距离定量分析气候变化对鱼类空间分布格局的影响。结果表明：(1)模型预测结果良好,各组模型的AUC值均高于0.85,影响目标鱼类潜在分布的主要驱动因子为海水表层温度和溶解氧;(2)8种中上层经济鱼类中,羽鳃鲐(Rastrelliger kanagurta)、鳓鱼(Ilisha elongata)等种类生境分布偏南,气候变化情景下分布北界可扩展至长江口,而鳀鱼(Engraulis japonicus)、青鳞小沙丁鱼(Sardinella zunasi)等种类主要分布在我国北方海域,气候变化情景下生境南缘边界退缩明显;(3)整体来看RCP8.5情景下的空间分布变化率大于RCP2.6情景,其中蓝圆鲹(Decapterus maruadsi)、青鳞小沙丁...     

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。