基于最大熵模型的狸尾豆属植物在中国的潜在分布区模拟

基于19个气候因子和203条狸尾豆属(Uraria)植物地理分布记录,采用最大熵模型(Max Ent)对植物当前分布点的气候变量进行分析,推断其在末次盛冰期(LGM)、当前和未来气候(2070s)情景下的潜在分布;采用受试者工作曲线和刀切法对模型的准确性进行检验并探明影响该属在中国分布的气候因子。结果显示:最大熵模型模拟结果极准确,测试集和训练集假阳性值(AUC)分别达到0.934和0.936;影响该属植物分布的主要气候因子是最暖季节降水和最冷月份最低温度;广西、广东及台湾地区为该属在中国的起源中心。在全球气候变暖背景下,狸尾豆属植物的适生环境将向中国北部及东部沿海地区推移,且面积逐渐增加。     

基于Maxent和ARCGIS的醉鱼草属植物适生区预测

为分析园林观赏植物醉鱼草属Buddleja在中国的潜在适生区,和环境因子对其在地理分布上的影响,基于世界气候数据网提供的19个气候因子数据,以及中国地区内128份可查证的分布点,运用最大熵模型及相关生物地理软件,模拟醉鱼草属植物在中国的潜在分布区,并通过刀切法得出影响其分布的主导气候因子.结果表明:醉鱼草属植物潜在适生...     

气候变化背景下基于MaxEnt模型的刺梨潜在适生区分布预测

为阐明气候变化背景下刺梨(Rosa roxburghii)在中国的潜在适生区分布,该研究基于刺梨的自然分布数据及当代(1960～1990)、未来(21世纪50年代及70年代)气候因子数据,采用最大熵(MaxEnt)模型模拟了当前和未来气候情景下刺梨在中国的潜在适生区,并确定影响其地理分布的主要气候因子.结果表明:(1)...     

气候变化背景下中国冷杉属植物地理分布模拟分析

中国是世界上冷杉属（Abies Mill.）植物种类最为丰富、分布地域最广的国家,也是研究冷杉属植物分布成因与规律的关键地区。本文通过中国数字植物标本馆、全球生物多样性信息数据库和相关文献三种途径收集我国冷杉属植物的地理分布数据,结合当前和未来气候情景,应用最大熵模型（MaxEnt）模拟冷杉属植物的潜在分布,并使用GIS的空间分析功能做生境适宜性分析,评估我国各地区对冷杉属植物的保护能力。结果显示：（1）四川西南部、云南北部、西藏自治区东南部是我国冷杉属植物分布的热点地区;（2）在未来气候变化情景下,我国冷杉属植物的适宜生境面积将明显减少;（3）适宜生境在未来有向北迁移的趋势;（4）就各地区保护能力而言,在当前气候情景下,云南省的保护能力最高,在未来,我国西部地区的保护能力呈上升趋势,中部和东部地区呈下降趋势。本研究可为冷杉属植物的保护工作提供一定的理论依据和参考价值。     

中国水稻潜在分布及其气候特征

基于全国层次和年尺度筛选的影响中国水稻分布的潜在气候指标,结合水稻地理分布信息,利用最大熵模型和ArcGIS软件的空间分析功能,分析了中国水稻潜在分布及其气候特征.结果表明:年降水量(P)、湿润指数(MI)、稳定通过18℃持续日数( N18)和≥10℃积温(∑T10)4个因子是影响水稻分布的主导气候因子,其累积贡献百分率达97.6％.采用主导气候因子作为环境变量重建气候水稻分布关系的最大熵模型,利用重建的最大熵模型给出的中国水稻存在概率,对中国水稻潜在分布区的气候适宜等级进行了划分,并分析了各适宜区的气候特征.研究结果可为中国水稻生产布局及制定应对气候变化政策提供参考.     

基于MaxEnt模型预测中国兰属植物的分布格局及主导气候因子(附表)

兰属(Cymbidium)中，除了兔耳兰C.lancifolium以外的所有种均被列为国家重点保护野生植物。为探究其在未来气候条件下的潜在分布格局，该研究基于兰属植物已知的分布点和19个气候因子，利用最大熵(MaxEnt)模型和地理信息系统(ArcGIS)模拟兰属以及其中20种兰属植物在9种不同气候情景(当代以及未来2030s、2050s、2070s和2090s 4个时间段各两种温室气体排放情景)下的潜在分布格局。结果表明：(1)最干旱季降水量(Bio17)、年降水量(Bio12)和温度季节性变化(Bio4)是影响兰属植物地理分布格局的主导气候因子。(2)不同兰属植物在未来情景下的适生区表现出不同的变化趋势，并且影响其分布的主导气候因子也有所不同。其中，冬凤兰(C.dayanum)等8个物种的适生区面积整体呈扩张趋势，而西藏虎头兰(C.tracyanum)等12个物种的适生区面积整体则呈缩减趋势。该研究结果为兰属植物就地保护与迁地保护提供了重要参考，对兰属等濒危野生植物的保护具有积极意义。     

基于MaxEnt模型模拟肯尼亚茜草科河骨木属植物的潜在分布及其在植物志中的应用初探

物种分布模型目前被广泛应用于生物学、生态学和保护生物学的各个领域。该文以肯尼亚茜草科河骨木属（Afrocanthium ）为例,利用最大熵模型（MaxEnt）模拟植物在当前气候情景下的潜在分布,并将这些分布图利用于正在编写的《肯尼亚植物志》中。结果显示,基于足够的原始标本记录,模型能够很好地模拟出每种植物的潜在分布区域。相比传统和新一代植物志仅提供标本信息点或是粗略分布图,《肯尼亚植物志》预采用的潜在分布图,将为志书使用者提供更加全面、实用的信息。     

气候变化下耐旱藓类连轴藓属在新疆的分布模拟

该研究基于耐旱藓类连轴藓属5种53条在新疆的地理分布信息和7个气候变量,利用最大熵模型和ArcGIS 10.2软件,分别模拟现代气候和未来气候情景下连轴藓属在新疆的适生分布区,为探讨气候变化对干旱、半干旱区苔藓植物物种分布的影响提供参考。结果表明:(1)Maxent模型预测连轴藓属在新疆适生区的准确性非常高(AUC=0.957)。(2)年降雨量、最干季度降雨量和最暖季度平均气温是影响连轴藓属分布的主要气候因子。(3)连轴藓属在新疆的适生区主要集中在阿尔泰山和天山沿线,在未来(2061~2080年)气候情景下,连轴藓属分布面积将比现代气候下减少10.39%,其绝大部分现有南部适生区将丧失。     

气候变化条件下苦参在我国潜在分布区的预测分析

为了解气候变化情景下苦参在中国的潜在分布区变化,探讨生物气候因子与苦参适宜分布格局的关系.该文通过收集苦参的地理分布点并结合19项生态因子,运用最大熵模型(MaxEnt)和地理信息系统(ArcGIS)对末次盛冰期、当前气候、未来气候三种气候情景下苦参在我国适生区的分布格局进行模拟,并分析影响苦参生长的主导生态因子.结果...     

中国兜兰属宽瓣亚属植物地理分布格局及其主导气候因子

为明确兜兰属宽瓣亚属(Paphiopedilum Subgen. Brachypetalum)植物在中国的自然地理分布格局及其主导气候因子,该研究以7种宽瓣亚属植物为研究对象并利用Arc GIS技术提取其在中国194个地理分布点的气候数据,采用描述性统计分析宽瓣亚属植物在中国分布区的气候特点,采用逐步回归拟合各气候因子与其经纬度分布的线性关系,最后通过冗余分析(RDA)和蒙特卡洛(Monte-Carlo)检验量化各气候因子对宽瓣亚属植物地理分布的贡献率。结果表明:(1)宽瓣亚属植物在中国主要分布于滇东南、黔西南、黔南、黔东北、滇西北、桂北与黔南交界处以及桂西北至桂西南地区。(2)该亚属植物在中国分布区的昼夜温差月均值、年平均气温变化范围、最暖季度平均气温、最冷季度平均气温4项热量因子的平均值分别为8.13、23.70、23.62和9.23℃,降水量变异系数、最湿季度降水量、最干季度降水量、干旱指数4项水分因子平均值分别为75.66%、673.10 mm、73.97 mm和26.12%,整体上具有湿热的气候特点;各物种间,狭域分布的物种与广布种间的气候因子存在显著差异。(3)逐步回归分析...     

应用排序分析藓类植物分类群分布与气候因素的关系

以我国21个山地藓类植物区系和气象资料为基础,应用典范对应分析(CCA)和除趋势典范对应分析(DCCA),比较了21个山地中藓类植物61个科,曲尾藓科(Dicranaceae)23个属、曲柄藓属(Campylopus)17种及曲尾藓属(Dicranum)35种分布与年均温度、>10℃积温、1月均温、7月均温、年均相对湿度、年均降雨量、年有雾天数、年有霜天数和年日照时数的关系,通过排序进行了直观的展示;同时还应用典范对应分析直观地反映了包括长白山在内的我国9个山地苔藓植物地理成分组成上的相似性及它们与气候因素间的关系.本文研究表明将DCCA和CCA应用到植物区系地理学研究上是可行的.     

Geographical Distribution of Testate Amoebae in Tibet and Northwestern Yunnan and their Relationships with Climate

In Asia, especially in China, our knowledge of the distribution of testate amoebae is still limited. In this paper, the geographical distribution of testate amoebae in Tibetan Plateau and northwestern Yunnan Plateau, southwest China and their relationships with the climatic factors have been studied. We found testate amoebae shifted in the most dominant species and increased in species (or genus) richness from northwest to southeast. Further, the linear regression analyses revealed that both species richness and genus richness have higher positive correlations with the mean temperature of the warmest month and annual mean precipitation as contrasted with the mean altitude, which showed weak negative correlation. This indicates that the temperature and precipitation are more significant influences on the richness than the altitude. The cluster analysis based on the community structure, defined by Sørenson’s coefficient matrix, suggested four groups from the 10 physiographical regions. This geographical distribution pattern was also closely related with the climatic regionalization. The present climatic regionalization pattern of the study area originated from the uplift of Tibetan Plateau and mainly occurred in or after the late Pleistocene. Therefore, the geographical distribution of testate amoebae in our study area may have experienced complicated and drastic changes corresponding to the variation of the climate caused by the geological events.     

Patterns of Diversity,Areas of Endemism,and Multiple Glacial Refuges for Freshwater Crabs of the Genus Sinopotamon in China (Decapoda: Brachyura: Potamidae)

Previous research has shown that the geographical distribution patterns of freshwater fishes and amphibians have been influenced by past climatic oscillations in China resulting from Pleistocene glacial activity. However, it remains unknown how these past changes have impacted the present-day distribution of Chinese freshwater crabs. This work describes the diversity and endemism of freshwater crabs belonging to Sinopotamon, a highly speciose genus endemic to China, and evaluates its distribution in terms of topography and past climatic fluctuations. Species diversity within Sinopotamon was found to be concentrated in an area from the northeastern edge of the Yunnan-Guizhou Plateau to the Jiangnan Hills, and three areas of endemism were identified. Multiple regression analysis between current climatic variables and Sinopotamon diversity suggested that regional annual precipitation, minimum temperature in the coldest month, and annual temperature range significantly influenced species diversity and may explain the diversity patterns of Sinopotamon. A comparison of ecological niche models (ENMs) between current conditions and the last glacial maximum (LGM) showed that suitable habitat for Sinopotamon in China severely contracted during the LGM. The coincidence of ENMs and the areas of endemism indicated that southeast of the Daba Mountains, and central and southeastern China, are potential Pleistocene refuges for Sinopotamon. The presence of multiple Pleistocene refuges within the range of this genus could further promote inter- and intraspecific differentiations, and may have led to high Sinopotamon species diversity, a high endemism rate and widespread distribution.     

Climatic Control on Forests and Tree Species Distribution in the Forest Region of Northeast China

North-east （NE） China covers considerable climatic gradients and all major forests types of NE Asia. in the present study, 10 major forest types across the forest region of NE China were sampled to Investigate forest distribution in relation to climate. Canonical correspondence analysis （CCA） revealed that growing season precipitation and energy availability were primary climatic factors for the overall forest pattern of NE China, accounting for 66% of the explanatory power of CCA. Conversely, annual precipitation and winter coldness had minor effects. Generalized additive models revealed that tree species responded to climatic gradients differently and showed three types of response curve： （i） monotonous decline; （ii） monotonous Increase; and （iii） a unimodai pattern. Furthermore, tree species showed remarkable differences in limiting climatic factors for their distribution. The power of climate in explaining species distribution declined significantly with decreasing species dominance, suggesting that the distribution of dominant species was primarily controlled by climate, whereas that of subordinate species was more affected by competition from other species.     

Effects of historical legacies on soil nematode communities are mediated by contemporary environmental conditions

Both contemporary and historical factors are documented to be crucial in regulating species diversity and distribution. Soil fauna contribute substantially to global biodiversity and ecosystem functioning, while it is unclear whether and to what extent historical factors shape their diversity patterns. Here, we used soil nematodes as a model organism to test historical effects on soil fauna and to investigate the relative importance of climatic, soil, and historical factors. Based on nematode distribution data in 16 natural sites at a large scale (ranging from 22 to 40°N) in mainland China, we conducted elastic net regression model to test the effects of climatic (e.g., mean and seasonality of temperature/precipitation), soil (e.g., soil carbon, nitrogen, and pH), and historical (e.g., temperature/precipitation anomaly and the velocity of the change since the Last Glacial Maximum) variables on nematode genus richness and Shannon's diversity. Additionally, variation partitioning was used to determine the contribution of the three predictor sets to the explanation of both Jaccard and Bray–Curtis community dissimilarity. We found that climate generally explained more variations in both diversity and composition than soil and historical predictors in our samples. We also showed that although historical factors (e.g., temperature change velocity) were correlated with nematode diversity and composition, the pure effects of these historical factors were negligible. In other words, the historical effects were commonly represented by their interactions with current climatic and soil factors within our selected sites. Our results indicated that contemporary factors, especially climate, may outperform historical factors in regulating soil nematode diversity patterns at large scales.     

中国木蓝属分布式样的数值分析及资源利用

本文根据国产木蓝属80种植物的地理分布,运用计算机以组平均法做聚类分析研究,将我国木蓝属划分为五个分布区,探讨了各区的自然地理、气候和植物区系特点及该属植物的分布规律。论述了木蓝属植物资源利用的近况及发展前景。     

基于MaxEnt生态位模型预测对齿藓属(Didymodon)植物在新疆的潜在地理分布

该文基于MaxEnt模型,利用获得的132个对齿藓属(Didymodon)植物在新疆分布的信息,结合RCP45 CO2排放情景下2050年和2070年的19个生物气候数据预测该属在当代、2050年和2070年的潜在分布区域。结果显示,最湿季平均温度、年平均气温、最干季降水量和年降水量是影响该属分布最主要的气候因子,其贡献率分别为33.6%、22.2%、16.4%和14.6%;模型模拟准确度高(AUC值达0.84);在当代气候条件下,对齿藓属植物的适宜生境面积占新疆总面积的38.51%;最适分布区域是中部的天山山脉、南部昆仑山脉的东部和西部的帕米尔高原;与当代的分布预测结果相比,未来(2050年和2070年)该属适宜栖息地分布范围总体上呈现退缩趋势;退缩后的适宜生境面积分别占新疆总面积的36.56%和37.87%。温度和降水量可能是引起对齿藓属地理分布退缩的重要气候因子。研究结果可为探讨气候变化对干旱、半干旱区苔藓植物物种分布的影响提供参考资料。     

First record of Eretmophyllum (Ginkgoales) with well-preserved cuticle from the Middle Jurassic of the Ordos Basin,Inner Mongolia,China

The genus Eretmophyllum, a characteristic and widespread taxon of the order Ginkgoales, is restricted in the Mesozoic floras of Eurasia. In China, although some specimens were assigned to Eretmophyllum based on gross leaf morphology, none have epidermal structure, which is essential for species delimitation within this genus. In this paper, we describe a new species, Eretmophyllum neimengguensis n. sp., from the Middle Jurassic Yan’an Formation of the Ordos Basin, China. This is the first record of the genus Eretmophyllum (Ginkgoales) from the Ordos Basin as well as from China based upon the gross leaf morphology and the epidermal structure. The new record significantly extends the stratigraphic and geographic distribution of Eretmophyllum in China and Eurasia. It also improves our understanding of its leaf morphology, epidermal structure, and past diversity. The taxonomic position and the stratigraphic and geographical range of the genus Eretmophyllum are discussed. Briefly, leaf morphological and epidermal characters of the new species, associated plant assemblages, and sedimentology indicate that the regional climate of the Ordos Basin was warm and humid with seasonal temperature and precipitation fluctuations in warm-temperate zone during the Middle Jurassic. Furthermore, given the relationship between the distribution/diversity of the genus and the climate, the genus Eretmophyllum may be confined to the warm-temperature climate, is intolerant of heat and frost, and can be considered as an indicator of humid and warm climatic conditions.     

我国单季稻种植区的气候适宜性

从国家层次和年尺度阐明影响我国单季稻种植区分布的主导气候因子, 揭示我国单季稻种植区的潜在分布及其气候适宜性,可为我国优化单季稻生产布局、改进种植制度和引种提供科学依据.本文从国家层次和年尺度选取影响我国单季稻分布的潜在气候因子, 利用其地理分布信息,结合最大熵模型和ArcGIS的空间分析功能, 阐明影响我国单季稻分布的主导气候因子并构建我国单季稻分布与气候的关系模型. 结果表明: 影响我国单季稻潜在种植区分布的主导气候因子是年降水量、湿润指数和稳定通过18 ℃日数, 它们对单季稻分布的累积贡献率达到了潜在气候因子的94.5%; 基于主导气候因子和单季稻种植点分布的地理信息, 结合最大熵模型构建的我国单季稻种植区分布与气候的关系模型能够很好地模拟我国单季稻种植区的潜在分布. 根据待预测区单季稻的存在概率, 明确了我国单季稻种植区潜在分布的气候低、中、高适宜区和气候不适宜区, 并分析了各气候适宜区的气候特征.