Fine-scale community and genetic structure are tightly linked in species-rich grasslands

Recent evidence indicates that grassland community structure and species diversity are influenced by genetic variation within species. We review what is known regarding the impact of intraspecific diversity on grassland community structure, using an ancient limestone pasture as a focal example. Two genotype-dependent effects appear to modify community structure in this system. First, the abundance of individual constituent species can depend upon the combined influence of direct genetic effects stemming from individuals within the population. Second, the outcome of localized interspecific interactions occurring within the community can depend on the genotypes of participating individuals (indicating indirect genetic effects). Only genotypic interactions are thought to be capable of allowing the long-term coexistence of both genotypes and species. We discuss the implications of these effects for the maintenance of diversity in grasslands. Next, we present new observations indicating that losses of genotypic diversity from each of two species can be predicted by the abundance of other coexisting species within experimental grassland communities. These results suggest genotype-specific responses to abundance in other coexisting species. We conclude that both direct and indirect genetic effects are likely to shape community structure and species coexistence in grasslands, implying tight linkage between fine-scale genetic and community structure.     

山西庞泉沟自然保护区森林群落物种多样性

在对山西庞泉沟自然保护区森林群落进行数量分类的基础上,运用丰富度指数、物种多样性指数和均匀度指数对保护区内森林群落的物种多样性进行了研究,并对森林群落各层片之间的物种多样性进行了相关性分析.结果表明:(1)森林群落15个群丛的丰富度指数、物种多样性指数和均匀度指数能很好地反映各群丛多样性变化规律.(2)各群丛的丰富度指数和物种多样性指数总体上呈现草本层＞灌木层＞乔木层,草本层的均匀度最小,大多数森林群落乔木层和灌木层的均匀度比较接近.(3) Patrick指数、Simpson指数、Shannon指数以及Pielou指数和Alatalo指数之间表现极显著差异性(P＜0.01).(4)群丛3(华北落叶松-土庄绣线菊+美蔷薇-东方草莓群丛)灌木层和草本层之间呈显著负相关(r=-0.643,P＜0.05);群丛8(白桦+山杨-灰栒子+美蔷薇-中亚苔草群丛)乔木层和灌木层呈显著负相关(r=-0.458,P＜0.05),灌木层和草本层则呈显著正相关(r=0.404,P＜0.05);群丛11(白杄-中亚苔草+烟管头草)的乔木层和草本层之间呈显著负相关(r=-0.949,P＜0.05).     

A global analysis of avian island diversity–area relationships in the Anthropocene

Research on island species–area relationships (ISAR) has expanded to incorporate functional (IFDAR) and phylogenetic (IPDAR) diversity. However, relative to the ISAR, we know little about IFDARs and IPDARs, and lack synthetic global analyses of variation in form of these three categories of island diversity–area relationship (IDAR). Here, we undertake the first comparative evaluation of IDARs at the global scale using 51 avian archipelagic data sets representing true and habitat islands. Using null models, we explore how richness-corrected functional and phylogenetic diversity scale with island area. We also provide the largest global assessment of the impacts of species introductions and extinctions on the IDAR. Results show that increasing richness with area is the primary driver of the (non-richness corrected) IPDAR and IFDAR for many data sets. However, for several archipelagos, richness-corrected functional and phylogenetic diversity changes linearly with island area, suggesting that the dominant community assembly processes shift along the island area gradient. We also find that archipelagos with the steepest ISARs exhibit the biggest differences in slope between IDARs, indicating increased functional and phylogenetic redundancy on larger islands in these archipelagos. In several cases introduced species seem to have ‘re-calibrated’ the IDARs such that they resemble the historic period prior to recent extinctions.     

Drawing ecological inferences from coincident patterns of population‐ and community‐level biodiversity

Biodiversity is comprised of genetic and phenotypic variation among individual organisms, which might belong to the same species or to different species. Spatial patterns of biodiversity are of central interest in ecology and evolution for several reasons: to identify general patterns in nature (e.g. species–area relationships, latitudinal gradients), to inform conservation priorities (e.g. identifying hotspots, prioritizing management efforts) and to draw inferences about processes, historical or otherwise (e.g. adaptation, the centre of origin of particular clades). There are long traditions in ecology and evolutionary biology of examining spatial patterns of biodiversity among species (i.e. in multispecies communities) and within species, respectively, and there has been a recent surge of interest in studying these two types of pattern simultaneously. The idea is that examining both levels of diversity can materially advance the above‐stated goals and perhaps lead to entirely novel lines of inquiry. Here, we review two broad categories of approach to merging studies of inter‐ and intraspecific variation: (i) the study of phenotypic trait variation along environmental gradients and (ii) the study of relationships between patterns of molecular genetic variation within species and patterns of distribution and diversity across species. For the latter, we report a new meta‐analysis in which we find that correlations between species diversity and genetic diversity are generally positive and significantly stronger in studies with discrete sampling units (e.g. islands, lakes, forest fragments) than in studies with nondiscrete sampling units (e.g. equal‐area study plots). For each topic, we summarize the current state of knowledge and key future directions.     

湘西北蜡梅群落典型样地的物种多样性特征初探

根据湘西北野生蜡梅〔Ｃｈｉｍｏｎａｎｔｈｕｓｐｒａｅｃｏｘ（Ｌ．）Ｌｉｎｋ〕群落典型样地的调查结果,对其物种多样性指数及其特征进行了综合测算与分析,结果表明：群落各层次的种群数量分布与多样性指数（除优势度指数外）的变化规律基本一致,从乔木层到草本层依次递增,显示出其林冠层下能够容纳丰富的物种多样性。将不同区域的样地之间多样性综合指标进行比较,并结合林木径级构成分析,发现处于人为活动影响下的蜡梅群落,其物种多样性逐渐退化,群落的发育速度减缓;而处于自然演替中的群落,其多样性综合指标较高,群落结构复杂且较稳定,顺向演替进程加快     

Genetic diversity of Ranunculus acris L. (Ranunculaceae) populations in relation to species diversity and habitat type in grassland communities

Correlates between genetic diversity at intra- and interpopulation levels and the species diversity in plant communities are rarely investigated. Such correlates may give insights into the effect of local selective forces across different communities on the genetic diversity of local plant populations. This study has employed amplified fragment length polymorphism to assess the genetic diversity within and between 10 populations of Ranunculus acris in relation to the species diversity (richness and evenness) of grassland communities of two different habitat types, 'seminatural' and 'agriculturally improved', located in central Germany. Within-population genetic diversity estimated by Nei's unbiased gene diversity (HE) was high (0.258-0.334), and was not correlated with species richness (Pearson's r = -0.17; P = 0.64) or species evenness (Pearson's r = 0.15; P = 0.68) of the plant communities. However, the genetic differentiation between R. acris populations was significantly correlated with the difference in species evenness (Mantel's r = 0.62, P = 0.02), but not with difference in species richness of plant communities (r = -0.17, P = 0.22). Moreover, we also found that populations of R. acris from the 'seminatural' habitat were genetically different (amova, P < 0.05) from those in 'agriculturally improved' habitats, suggesting that gene flow between these habitat types is limited. The results reported in this study may indicate that habitat characteristics influence the genetic diversity of plant species.     

大青沟森林植物群落物种多样性研究

大青沟森林植物种类非常丰富,约占内蒙古自治区植物种数的三分之一,生物资源十分丰富。本文分别用Simpson指数、Shannon-Wienner指数和均匀度指数计测生态优势度、不同植物群落的物种多样性、群落物种多度的均匀度。结果表明：由于大青沟森林植物群落属于隐域性植被,从沟底到沟沿,小气候的差异较为明显,存在着生境梯度,但由于乔、灌、草综合作用的影响,各群落类型及生境梯度上的物种多样性的差异不十分明显。这可能是特殊森林群落类型长期适应隐域性生境条件的结果,它为我们改造周边环境提供了有益的启示。     

梵争山和张家界地区蜘蛛群落结构及多样性研究

1990年8月对梵净山和张家界两个自然保护区内蜘蛛群落进行调查,结果表明:自然保护区内蜘蛛资源极为丰富,经初步鉴定,计有蜘蛛27科85属180种,其中主要成分依次为肖蛸、园蛛、狼蛛、球蛛和皿蛛等。蜘蛛发生量折合每亩为17,585—54,000头。八个不同生境类型蜘蛛群落的种类数和密度存在明显差异;各种蜘蛛分布群在群落内的比例随栖息地结构变化而改变,因而也导致蜘蛛群落的Shannon-Wiener多样性指数,Simpson优势度和均等度等参数的变化。     

Spatiotemporal heterogeneity of plankton communities in Lake Donghu, China, as revealed by PCR–denaturing gradient gel electrophoresis and its relation to biotic and abiotic factors

The 16S and 18S rRNA genes of planktonic organisms derived from five stations with nutrient gradients in Lake Donghu, China, were studied by PCR–denaturing gradient gel electrophoresis (DGGE) fingerprinting, and the relationships between the genetic diversity of the plankton community and biotic/abiotic factors are discussed. The concentrations of total nitrogen (TN), total phosphorus (TP), NH₄-N and As were found to be significantly related ( P <0.05) to morphological composition of the plankton community. Both chemical and morphological analyses suggested that temporal heterogeneity was comparatively higher than spatial heterogeneity in Lake Donghu. Although the morphological composition was not identical to the DGGE fingerprints in characterizing habitat similarity, the two strongest eutrophic stations (I and II) were always initially grouped into one cluster. Canonical correspondence analysis suggested that the factors strongly correlated with the first two ordination axes were seasonally different. The concentrations of TN and TP and the densities of rotifers and crustaceans were generally the main factors related to the DGGE patterns of the plankton communities. The study suggested that genetic diversity as depicted by metagenomic techniques (such as PCR-DGGE fingerprinting) is a promising tool for ecological study of plankton communities and that such techniques are likely to play an increasingly important role in assessing the environmental conditions of aquatic habitats.     

海南万宁青皮林群落多样性特征研究

根据样方调查,对海南万宁青皮林群落的种类组成、外貌、结构特征和物种多样性进行分析。结果表明:(1)海南万宁青皮林自然保护区有维管植物137种,隶属于62科110属,其中热带性分布种达95.5%,群落属于热带雨林植被类型中的海岸单优青皮群落。(2)群落的优势种为青皮,外貌常绿,生活型以小高位芽为主(占35.04%),青皮种群表现为增长趋势。(3)群落的物种丰富度Magarlef指数为34.30,Shannon-Wienner指数为2.31,Simpson指数为0.99,均匀度Pielou指数为1.08。(4)群落各层次的丰富度表现为乔木层>灌木层>藤本植物>草本层,Simpson指数表现为灌木层>草本层>藤本植物>乔木层,Shannon-Wienner指数表现为灌木层>藤本植物>草本层>乔木层,均匀度表现为草本层>灌木层>藤本植物>乔木层,表明乔木层的物种丰富度最高,但分布最不均匀,优势种的优势地位突出。     

长山列岛邻近海域鱼类群落种类组成和多样性时空变化

为了解黄、渤海生态系统交错带长山列岛邻近水域鱼类群落种类组成和多样性,根据2016年10月,2017年1月、5月及8月进行的鱼类资源底拖网调查数据,应用相对重要性指数、物种多样性指数、k优势度曲线等方法,研究了长山列岛邻近海域鱼类群落种类组成、物种多样性时空变化及其与环境因子的关系。结果表明: 该海域共计捕获鱼类77种,以温水性、底层、洄游性鱼类为主,优势种组成季节变化明显,春季、冬季主要优势种为黄鮟鱇,夏季以日本鲭、鳀等中上层鱼类为主。全年共计出现洄游性鱼类46种,季节间物种迁移指数均在100以上,其中秋季物种迁移指数最大。鱼类群落物种丰富度指数在春季最高、Shannon多样性指数和均匀度指数在秋季最高。夏季物种丰富度指数与表层水温呈显著负相关;冬季物种丰富度指数与水深、底层水温呈极显著正相关,Shannon多样性指数与底层水温呈极显著正相关。长山列岛邻近海域作为黄、渤海两大生态系统的交错带,鱼类群落表现出高物种多样性、洄游种多以及明显的时空异质性。     

土壤肥力和物种属性决定亚高寒草甸实验群落的生产力

生物多样性与生态系统功能之间的关系及其形成的内在机制还存在很多争议。为了揭示植物群落生产力形成的生态学机制, 采用盆栽方法探讨了物种多样性、物种属性以及施肥水平与植物群落生产力之间的关系。研究结果显示: 在不施肥和每盆施5.0 g磷酸二铵的条件下, 随着物种多样性的增加, 地上生物量增加不显著; 在每盆施10.0 g磷酸二铵的条件下, 随着物种多样性的增加, 地上生物量显著增加。相对于中华羊茅(Festuca sinensis)而言, 垂穗披碱草(Elymus nutans)和垂穗鹅观草(Roegneria nutans)对群落生产力的贡献较大, 但在不同施肥水平和播种密度下, 其影响不完全相同。这表明物种多样性对群落生产力的影响随着土壤肥力的变化而变化; 并且植物群落生产力受组成群落的物种属性影响较大, 而物种属性又与特定时间和特定生境下资源的利用方式相联系。在高肥力水平下, 物种多样性之所以对群落生产力具有正效应, 可能是因为高肥力水平增加了可利用的生态位空间, 最终仍体现在物种组合上。因此, 植物群落的生产力与物种多样性之间没有必然的联系, 而与土壤肥力和土壤肥力决定的物种属性有关。     

Studies on species diversity of Larix chinensis community ecotone

The communities of Larix chinensis and their ecotone in Qinling Mountains were investigated by sampling belt method.Species richness,Simpson diversity,Shannon-Weiner diversity,PIE and Pielou evenness indices of vascular plants in their communities and ecotone were calculated.Structure and composition of the communities in 6 sampling belts within the sites were analyzed.The results showed that the edge effect was obvious in the ecotone with a less changing environment(such as soil and terrain)and acute variation of composition and structure,while inconspicuous or even none in the ecotone with worse environmental condition(such as great space fluctuation).It is apparent that the edge effect of community was affected by soil and terrain,but not by microclimate.     

Studies on species diversity of Larix chinensis community ecotone

The communities of Larix chinensis and their ecotone in Qinling Mountains were investigated by sampling belt method. Species richness, Simpson diversity, Shannon-Weiner diversity, PIE and Pielou evenness indices of vascular plants in their communities and ecotone were calculated. Structure and composition of the communities in 6 sampling belts within the sites were analyzed. The results showed that the edge effect was obvious in the ecotone with a less changing environment (such as soil and terrain) and acute variation of composition and structure, while inconspicuous or even none in the ecotone with worse environmental condition (such as great space fluctuation). It is apparent that the edge effect of community was affected by soil and terrain, but not by microclimate. __________ Translated from Guibaia, 2005, 25 (2)[译自: 广西植物, 2005,25(2)]     

武夷山景区松林节肢动物群落的组成与结构

对武夷山风景区5块马尾松林标准地的节肢动物群落进行2a的系统调查,共采集到林冠层节肢动物标本19938号,隶属于2纲16目87科200种;林下层节肢动物标本15807号,隶属于2纲17目103科224种。林冠层和林下层类群目的组成基本一致,但在科和物种数上存在着明显的差异。时间序列上的多样性分析表明,林下层物种的丰富度和多样性高于林冠层,总体上武夷山风景区马尾松林节肢动物群落相对较稳定。     

THE SPECIES RICHNESS AND DIVERSITY OF THE ARTHROPOD COMMUNITIES IN RICE FIELDS

Abstract The present paper deals with the characteristics of species richness and diversity of the arthropod communities in different rice fields and at various growing stages of rice based on the data ob tained from field surveys and the measurement of the community diversity. The field surveys were carried out in three different locations which represented three typical rice-growing habitats: mountainous, plain and hilly fields in the suburb of Fuzhou, Fujian Province in 1994. Shannon-Wiener's (1949) average information content(H), Hurlbert's(1971) probability of interspecific encounter (PIE) and Pielou's (1966) formula of equitability (E) were used to measure the diversity of the arthropod communities in the ecosystem of rice fields. The result showed that the species richness of herbivorous insects, carnivorous insects, spiders and total species in the community varied with different fields because of the influence of environmental variables in the habitats, and fluctuated with various growing stages of rice due to the variation of crop nourishment. Changes in the index values of H, PIE and E indicated that the cornmunity diversity and equitability also varied with space (habitats formed by the rice fields) and time (growing stages of rice). The author thinks that the results of the study could be applied to predict and forecast the population dynamics of rice pests, and to develop the rational program of integrated pest management in the specific rice fields. Discussions are also given in some detail on the methodology of measurement of the species richness and diversity of the arthropod communities in rice fields.     

宏生态学(Macroecology)及其研究

宏生态学是生态学与其他宏观学科不断交叉和融合后的产物。它以个体、种群和物种的生态特征在大时空尺度上的格局和变化规律为主要研究内容,它比其他生态学更强调归纳和推论,也更依赖数据的积累。近年来,宏生态学在对物种一面积关系进行探讨的基础上,对生物类群间的物种数量的协同变化以及物种和高级分类单元间的关系等进行了新的研究;宏生态学试图将有机论和个体论结合来探讨和总结群落结构中的物种组成规律;并对物种多度和分布格局间的关系从生态位和异质种群角度进行新的解释;个体大小频次分布规律是宏生态学一重要内容,对其深入研究和探讨已与物种多度、能量、分布面积、历史起源等多方面特征相结合,并得到一些普遍性规律;最后,宏生态学还探讨物种在地理区域上的普遍性的分布模式,并对其假说进行检验和探讨。宏生态学在中国还处于刚起步阶段,但中国具有资源的优势,并具有一定的数据积累,将在宏生态学研究中发挥越来越重要的作用。     

海南岛霸王岭两种典型热带季雨林群落特征

热带季雨林为海南岛的隐域性植被类型,分布在与热带低地雨林相似的海拔范围但生境条件较差的局部地段,在旱季其大部分的乔木种类和个体都会落叶.海南岛霸王岭林区分布着海南岛最为典型且大都保存较为完好的热带季雨林原始林,按照其优势树种可划分为海南榄仁(Terminalia hainanensis)季雨林和枫香(Liquidambar formosana)季雨林两种群落类型.通过对霸王岭林区两种典型的热带季雨林老龄林群落的样地调查,比较分析了其物种组成、大小结构、多样性、季相变化等特征.结果表明:海南岛热带季雨林群落中物种优势度明显,具有明显的标志种--海南榄仁和枫香.海南榄仁群落具有较高的灌木物种丰富度、个体多度及较低的乔木物种丰富度、个体多度和多样性;海南榄仁群落在小径级和低高度级中具有较高的植物个体多度,同时在低高度级中具有较低的物种丰富度,但其它径级和高度级两个群落物种丰富度及个体多度差异均不显著;除灌木落叶物种丰富度海南榄仁群落显著高于枫香群落外,其余各生长型落叶物种丰富度及个体多度两个群落之间均无显著差异;在具刺木质藤本物种丰富度和个体多度上海南榄仁群落与枫香群落差异不显著,但乔木、灌木和木本植物具刺物种丰富度及个体多度海南榄仁群落均显著高于枫香群落.总体来看,海南榄仁群落比枫香群落的季雨林特征明显,是海南岛最为典型的季雨林群落类型.     

抗感白粉病青稞的内生真菌群落差异分析

种子内生微生物组与种子的健康发育有着密切的关系。本研究收集对白粉病抗病和易感共11个品种的青稞种子,利用扩增子测序技术对内生真菌的群落、丰度和多样性进行研究。从不同品种的青稞种子中共鉴定4个门、17个纲、35个目、66个科、107个属的内生真菌,其中子囊菌门Ascomycota、担子菌门Basidiomycota和被孢菌门Mortierellomycota是优势菌门;链格孢属Alternaria、微座孢属Microdochium、亚隔孢壳属Didymella、镰刀菌属Fusarium和球腔菌属Mycosphaerella为优势菌属。根据生物信息学注释结果,在鉴定到的107个属中,抗病品种的青稞种子中特有的属有20个,感病品种的青稞种子中特有的属有50个;通过对两组样本的分析,发现感病品种中真菌物种多样性高于抗病品种。本研究通过扩增子测序技术初步确定了青稞抗、感白粉病两组样品中的真菌群落结构和优势菌群,为进一步研究青稞内携真菌与抗/感病的关系提供了基础,从内生菌的角度为青稞白粉病的防控提供新的策略。