Host plant genus-level diversity is the best predictor of ectomycorrhizal fungal diversity in a Chinese subtropical forest

Microbial diversity is generally far higher than plant diversity, but the relationship between microbial diversity and plant diversity remains enigmatic. To shed light on this problem, we examined the diversity of a key guild of root-associated microbes, that is, ectomycorrhizal (EM) fungi along a plant diversity gradient in a Chinese subtropical forest. The results indicated that EM fungal diversity was positively correlated with host plant diversity. Furthermore, this relationship was best predicted by host genus-level diversity, rather than species-level diversity or family-level diversity. The generality of this finding was extended beyond our study system through the analyses of 100 additional studies of EM fungal communities from tropical and temperate forests. Here as well, EM fungal lineage composition was significantly affected by EM plant diversity levels, and some EM fungal lineages were co-associated with some host plant genera. These results suggest a general diversity maintenance mechanism for host-specific microbes based on higher order host plant phylogenetic diversity.     

北京东灵山辽东栎林植物物种多样性的多尺度分析

多尺度分析物种多样性格局能够为有效保护生物多样性提供重要信息.利用物种多样性的加法分配法则分析了样方-坡位-坡面等级尺度系统辽东栎林植物物种多样性(gamma多样性)的alpha多样性和beta多样性在各尺度上的分配关系.结果表明以物种丰富度为指标的区域物种多样性的最大贡献来自坡面尺度,表明坡面尺度是维持辽东栎林物种多样性的有效尺度;而对Simpson多样性和Shannon多样性的最大贡献则来自样方内,这决定于群落物种优势度和稀有度格局;各尺度间beta多样性组分随尺度的增大而增大可能是环境异质性和扩散作用的综合结果.各尺度间Shannon多样性对总体多样性的贡献大于Simpson多样性的贡献是偶见种在各尺度间分配的结果.物种多样性分配的加法法则为物种多样性格局的多尺度分析提供了理论框架,是检验物种多样性格局形成机制的有效方法.     

Latitudinal gradients of associations between beta and gamma diversity of trees in forest communities in the New World

Aims We analyze two continental data sets of forest communities from across the New World to examine the latitudinal gradients of beta diversity after accounting for gamma diversity and the latitudinal gradient of gamma diversity after accounting for beta diversity.Methods Correlation and regression analyses were used to relate beta and gamma diversity to latitude along two latitudinal gradients in the New World (one including 72 forest sites located south of the equator and the other including 79 forest sites located north of the equator).Important findings Beta diversity and gamma diversity were negatively correlated with latitude. Beta diversity was strongly and positively correlated with gamma diversity (Pearson's correlation coefficient: 0.783 for New World North and 0.848 for New World South). When beta diversity was regressed on latitude and gamma diversity, 69.8 and 85.7% of the variation in beta diversity were explained, respectively, for New World North and New World South. When gamma diversity was regressed on latitude and beta diversity, 81.8 and 84.3% of the variation in gamma diversity were explained, respectively, for New World North and New World South. After statistically removing the relationship between beta and gamma diversity, latitude has weak or no relationships with beta and gamma diversity. However, strong positive correlations between beta and gamma diversity may not be considered as evidence of one driving the other along a latitudinal gradient.     

Beyond taxonomic diversity patterns: how do α, β and γ components of bird functional and phylogenetic diversity respond to environmental gradients across France?

Aim To test how far can macroecological hypotheses relating diversity to environmental factors be extrapolated to functional and phylogenetic diversities, i.e. to the extent to which functional traits and evolutionary backgrounds vary among species in a community or region. We use a spatial partitioning of diversity where regional or γ‐diversity is calculated by aggregating information on local communities, local or α‐diversity corresponds to diversity in one locality, and turnover or β‐diversity corresponds to the average turnover between localities and the region. Location France. Methods We used the Rao quadratic entropy decomposition of diversity to calculate local, regional and turnover diversity for each of three diversity facets (taxonomic, phylogenetic and functional) in breeding bird communities of France. Spatial autoregressive models and partial regression analyses were used to analyse the relationships between each diversity facet and environmental gradients (climate and land use). Results Changes in γ‐diversity are driven by changes in both α‐ and β‐diversity. Low levels of human impact generally favour all three facets of regional diversity and heterogeneous landscapes usually harbour higher β‐diversity in the three facets of diversity, although functional and phylogenetic turnover show some relationships in the opposite direction. Spatial and environmental factors explain a large percentage of the variation in the three diversity facets (>60%), and this is especially true for phylogenetic diversity. In all cases, spatial structure plays a preponderant role in explaining diversity gradients, suggesting an important role for dispersal limitations in structuring diversity at different spatial scales. Main conclusions Our results generally support the idea that hypotheses that have previously been applied to taxonomic diversity, both at local and regional scales, can be extended to phylogenetic and functional diversity. Specifically, changes in regional diversity are the result of changes in both local and turnover diversity, some environmental conditions such as human development have a great impact on diversity levels, and heterogeneous landscapes tend to have higher diversity levels. Interestingly, differences between diversity facets could potentially provide further insights into how large‐ and small‐scale ecological processes interact at the onset of macroecological patterns.     

Multitrophic effects of experimental changes in plant diversity on cavity-nesting bees, wasps, and their parasitoids

Plant diversity changes can impact the abundance, diversity, and functioning of species at higher trophic levels. We used an experimental gradient in grassland plant diversity ranging from 1 to 16 plant species to study multitrophic interactions among plants, cavity-nesting bees and wasps, and their natural enemies, and analysed brood cell density, insect diversity (species richness), and bee and wasp community similarity over two consecutive years. The bee and wasp communities were more similar among the high (16 species) diversity plots than among plots of the lower diversity levels (up to 8 species), and a more similar community of bees and wasps resulted in a more similar community of their parasitoids. Plant diversity, which was closely related to flower diversity, positively and indirectly affected bee diversity and the diversity of their parasitoids via increasing brood cell density of bees. Increasing plant diversity directly led to higher wasp diversity. Parasitism rates of bees and wasps (hosts) were not affected by plant diversity, but increased with the diversity of their respective parasitoids. Decreases in parasitism rates of bees arose from increasing brood cell density of bees (hosts), whereas decreasing parasitism rates of wasps arose from increasing wasp diversity (hosts). In conclusion, decreases in plant diversity propagated through different trophic levels: from plants to insect hosts to their parasitoids, decreasing density and diversity. The positive relationship between plant diversity and the community similarity of higher trophic levels indicates a community-stabilising effect of high plant diversity.     

Species diversity and genetic diversity: parallel processes and correlated patterns

Species diversity and genetic diversity may be correlated as a result of processes acting in parallel at the two levels. However, no theories predict the conditions under which different relationships between species diversity and genetic diversity might arise and therefore when one level of diversity may be predicted using the other. I used simulation models to investigate the parallel influence of locality area, immigration rate, and environmental heterogeneity on species diversity and genetic diversity. The most common pattern was moderate to strong positive species-genetic diversity correlations (SGDCs). Such correlations may be driven by any one of the three locality characteristics examined, but important exceptions and patterns emerged. Genetic diversity and species diversity were more weakly correlated when genetic diversity was measured for rare versus common species. Environmental heterogeneity not only imposes spatially varying selection on populations and communities but also causes changes in species' population sizes and therefore genetic diversity; these interacting processes can create positive, negative, or unimodal relationships of genetic diversity with species diversity. When species are considered as part of multispecies communities, predictions from single-species models of genetic diversity apply in some instances (effects of area and immigration) but often not in others (effects of environmental heterogeneity).     

Additive diversity partitioning in palaeobiology: revisiting Sepkoski’s question

Abstract: Using Whittaker’s concepts of alpha, beta, and gamma diversity, Sepkoski asked how global diversity was assembled at scales ranging from the community to the province. In the years since, ecologists have recast diversity in terms of additive partitions where total diversity can be decomposed into sample‐level alpha diversity plus the sum of a series of beta diversity terms that reflect progressively larger spatial scales. Given that marine alpha diversity represents a tiny fraction of global diversity, Phanerozoic global diversity patterns must be dominated by changes in beta diversity at one or more scales. A ballooning ecological literature demonstrates wide variation in beta diversity among ecosystems, regions, and taxa, suggesting that large changes in beta diversity on evolutionary timescales are likely. But the question is which scales are the most important. Several recent palaeontological studies help to constrain beta diversity within sedimentary basins, and the emergence of sample‐based databases puts an answer to Sepkoski’s question within reach. A new method for calculating diversity partitions for richness is introduced, which allows the calculation of each species’ contribution to alpha and beta diversity, as well as the contribution of each sampling unit to beta diversity.     

内蒙古典型草原建群种羊草基因型多样性抑制群落物种多样性的生态功能

植物群落的物种多样性以及群落建群种的基因型多样性对群落生态功能是否存在交互影响已成为群落生态学研究的热点内容。以内蒙古典型草原群落内常见物种为研究对象,研究了群落物种多样性与建群种羊草(Leymus chinensis)基因型多样性及其交互作用对群落生物量生态功能特性的影响。结果表明:(1)羊草基因型多样性、物种多样性及其交互作用对群落地上、地下和总生物量无显著影响(P0.05);(2)羊草基因型多样性、物种多样性及其交互作用对多样性效应(净多样性效应、互补效应和选择效应)有显著影响(P0.05)。羊草基因型多样性抑制多样性净效应的发挥,且主要抑制互补效应;而物种多样性则促进多样性净效应的发挥,主要表现为选择效应对地上生物量的正效应;(3)互补效应对群落生物量多样性净效应起主要贡献。实验所得结果不仅为探讨多样性效应在物种水平以及群落水平上对群落生物量的影响因素提供了重要启示,而且为内蒙古草原种质资源的保护及合理利用,乃至生态系统的恢复和重建提供理论指导。     

Spatial patterns of dicot diversity in Argentina

In this paper, we analyzed the taxonomic diversity of the Argentine dicots to evaluate their relationships with area, latitude, and longitude. We also evaluated species diversity and higher taxa diversity relationships. The families, genera and species diversity in Argentine dicots was not explained by the area of each province but it varied through latitudinal and longitudinal gradients. The taxonomic diversity of these plants increased from high to low latitudes and west–east longitudes. These patterns would explain why the main diversity centers are located in the North region of this country. As we expected the species diversity and higher taxa diversity showed a positive relationship. At this scale, higher taxa diversity could be use as surrogate for species diversity.     

On hierarchical diversity decomposition

Abstract. Question: According to Whittaker's proposal, ecologists have traditionally viewed β‐diversity as the ratio between γ‐diversity and average α‐diversity. More recently, an alternative way of partitioning diversity has been ‘rediscovered’for which β‐diversity is obtained as the difference between γ‐diversity and average α‐diversity. This additive way of partitioning diversity has rapidly become a very popular framework for hierarchical diversity decomposition at various spatial scales. The question for this study is: Can we highlight any relation between these two ways of partitioning diversity, or do these methods really capture different facets of spatial turnover in species composition? Methods: First the properties that a diversity measure should possess for enabling additive decomposition into α‐, β‐, and γ‐components are reviewed. Next, attention is drawn to the relationships between additive and multiplicative diversity decomposition. Results: It is shown that the additive model is closely related to its multiplicative counterpart through a simple logarithmic transformation. Conclusions: Contrary to the current assumption, both methods for partitioning diversity are not as different as they appear. Hence, the supposed superiority of additive diversity partition over multiplicative diversity decomposition is largely unjustified.     

Is there a trade-off between species diversity and genetic diversity in forest tree communities?

The two most important components of biodiversity, species diversity and genetic diversity, have generally been treated as separate topics, although a coordination between both components is believed to be critical for ecosystem stability and resilience. Based on a new trait concept that allows for the assessment of genetic diversity across species, the relationship between species diversity and genetic diversity was examined in eight forest tree communities composed of different tree genera including both climax and pioneer species. It was intended to check whether a trade-off exists between the two diversity components as was found in a few studies on animal species.Using several isozyme-gene systems as genetic markers, the genetic diversity across species within each of the tree communities was determined by two measures, the commonly used intraspecific genetic diversity averaged over species and the recently developed transspecific genetic diversity per species. Both data sets were compared with the corresponding community-specific species diversity resulting in a positive relationship between the two diversity components. A statistically significant positive correlation was established between the transspecific genetic diversity per species and the species diversity for three isozyme-gene systems. Beyond that, consistent results were obtained using different parameters of the diversity measure which characterize the total, the effective and the number of prevalent variants. The number of prevalent variants reflected most significantly the non-randomness of the observed diversity patterns.These findings can be explained by the observation that the pioneer tree species reveal a by far higher genetic diversity than the climax tree species, which means that an increase in species diversity, due to the addition of several pioneer species at the expense of one or two climax species, goes along with an increase in the level of genetic diversity. Forest tree communities with the highest degree of species diversity exhibit therefore the highest transspecific genetic diversity per species. This result was discussed with regard to the particular composition and stability of forest tree communities.     

On the relationship between plant species diversity and genetic diversity of Plantago lanceolata (Plantaginaceae) within and between grassland communities

Aims and Methods The relationship between genetic diversity and species diversity and the underlying mechanisms are of both fundamental and applied interest. We used amplified fragment length polymorphism (AFLP) and vegetation records to investigate the association between genetic diversity of Plantago lanceolata and plant species diversity using 15 grassland communities in central Germany. We used correlation and partial correlation analyses to examine whether relationships between genetic and species diversity were direct or mediated by environmental differences between habitats.Important findings Both within- and between-population genetic diversity of P. lanceolata were significantly positively correlated with plant species diversity within and between sites. Simple and partial correlations revealed that the positive correlations indirectly resulted from the effects of abiotic habitat characteristics on plant species diversity and, via abundance, on genetic diversity of P. lanceolata. Thus, they did not reflect a direct causal relationship between plant species diversity and genetic diversity of P. lanceolata, as would have been expected based on the hypothesis of a positive relationship between plant species diversity and niche diversity.     

菌根多样性及其对植物生长发育的重要意义

菌根多样性是生物多样性的重要组成部分。主要包括形态多样性、物种多样性和功能多样性．大量试验表明。菌根多样性对植物物种的起源与进化、分布与生存、生长和发育等方面起着至关重要的作用。而植物多样性又决定了菌根多样性．认为菌根多样性与植物多样性是相辅相成、相互制约的。随着分子生物学技术的不断发展和完善。必将使菌根多样性的研究得到快速发展．     

Experimental tests of the dependence of arthropod diversity on plant diversity

ABSTRACT Because a diversity of resources should support a diversity of consumers, most models predict that increasing plant diversity increases animal diversity. We report results of a direct experimental test of the dependence of animal diversity on plant diversity. We sampled arthropods in a well-replicated grassland experiment in which plant species richness and plant functional richness were directly manipulated. In simple regressions, both the number of species planted ([Formula: see text] transformed) and the number of functional groups planted significantly increased arthropod species richness but not arthropod abundance. However, the number of species planted was the only significant predictor of arthropod species richness when both predictor variables were included in ANOVAs or a MANOVA. Although highly significant, arthropod species richness regressions had low [Formula: see text] values, high intercepts (24 arthropod species in monocultures), and shallow slopes. Analyses of relations among plants and arthropod trophic groups indicated that herbivore diversity was influenced by plant, parasite, and predator diversity. Furthermore, herbivore diversity was more strongly correlated with parasite and predator diversity than with plant diversity. Together with regression results, this suggests that, although increasing plant diversity significantly increased arthropod diversity, local herbivore diversity is also maintained by, and in turn maintains, a diversity of parasites and predators.     

水稻SSR标记的遗传多样性研究进展

本文从SSR标记优点和适用于研究水稻遗传多样性入手,综述了SSR标记在水稻核心种质构建与评价、遗传结构、稻种起源演化等方面的研究进展。总结了水稻遗传多样性的地带性特征（云南是中国稻种资源的最大遗传多样性中心和优异种质的富集地;西南稻区粳稻品种遗传多样性最丰富;南方稻区粳稻品种的遗传多样性高于北方粳稻遗传多样性）、遗传多样性与生态地理位置密切相关、目前水稻品种遗传基础狭窄、多样性降低等特征,分析了遗传多样性成因及影响因素,特别指出了育种行为对遗传多样性的影响,并针对当前水稻品种遗传多样性较低的问题提出了对策。     

Perspectives of genomics for genetic conservation of livestock

Genomics provides new opportunities for conservation genetics. Conservation genetics in livestock is based on estimating diversity by pedigree relatedness and managing diversity by choosing those animals that maximize genetic diversity. Animals can be chosen as parents for the next generation, as donors of material to a gene bank, or as breeds for targeting conservation efforts. Genomics provides opportunities to estimate diversity for specific parts of the genome, such as neutral and adaptive diversity and genetic diversity underlying specific traits. This enables us to choose candidates for conservation based on specific genetic diversity (e.g. diversity of traits or adaptive diversity) or to monitor the loss of diversity without conservation. In wild animals direct genetic management, by choosing candidates for conservation as in livestock, is generally not practiced. With dense marker maps opportunities exist for monitoring relatedness and genetic diversity in wild populations, thus enabling a more active management of diversity.     

Relationship between genetic, chemical, and bacterial diversity in the Atlanto-Mediterranean bath sponge Spongia lamella

Does diversity beget diversity? Diversity includes a diversity of concepts because it is linked to variability in and of life and can be applied to multiple levels. The connections between multiple levels of diversity are poorly understood. Here, we investigated the relationships between genetic, bacterial, and chemical diversity of the endangered Atlanto-Mediterranean sponge Spongia lamella. These levels of diversity are intrinsically related to sponge evolution and could have strong conservation implications. We used microsatellite markers, denaturing gel gradient electrophoresis and quantitative polymerase chain reaction, and high performance liquid chromatography to quantify genetic, bacterial, and chemical diversity of nine sponge populations. We then used correlations to test whether these diversity levels covaried. We found that sponge populations differed significantly in genetic, bacterial, and chemical diversity. We also found a strong geographic pattern of increasing genetic, bacterial, and chemical dissimilarity with increasing geographic distance between populations. However, we failed to detect significant correlations between the three levels of diversity investigated in our study. Our results suggest that diversity fails to beget diversity within a single species and indicates that a diversity of factors regulates a diversity of diversities, which highlights the complex nature of the mechanisms behind diversity.     

戴云山物种多样性与系统发育多样性海拔梯度分布格局及驱动因子

生物多样性的海拔分布格局是生态学研究的热点。海拔作为综合性因子驱动着植物群落的物种、系统发育与功能多样性的空间分布。以戴云山南坡900-1600 m森林植物群落为研究对象,探讨物种多样性、系统发育指数与环境驱动因子的相互关系以及环境因子在群落构建与多样性维持中的重要意义。结果表明：（1）森林植物群落的系统发育多样性与物种多样性沿海拔均呈现中间高度膨胀格局。（2）物种多样性Margalef指数、Shannon-Wiener指数与系统发育多样性指数呈显著正相关,表明物种多样性越高,系统发育多样性也越高。Shannon-Wiener指数与物种多样性指数（Margalef、Pielou、Simpson指数）、系统发育多样性及系统发育结构都存在显著相关性,一定程度上Shannon-Wiener指数可以代替其他指数。Pielou指数、Simpson指数、Shannon-Wiener指数与系统发育结构NRI （Net relatedness index）指数、NTI （Net nearest taxa index）指数存在显著正相关,表明群落优势度、均匀度与系统发育结构相关性较强。（3）土壤全磷含量是影响系统发育多样性和物种多样性的主要驱动因子,土壤含水量是影响Shannon-Wiener、Pielou、Simpson指数的最显著因子,海拔是影响群落系统发育结构的主要因素。海拔是影响系统发育结构变化的主要环境因子,而土壤因子是影响物种多样性与系统发育多样性的主要因素,进一步验证了物种多样性与系统发育多样性的高度相关,结果旨在揭示物种群落空间分布规律。     

植物群落物种多样性研究综述

物种多样性是生物多样性在物种水平上的表现形式 ,包括两方面的含义 ,一是指一定区域内物种的总和 ,主要从分类学、系统学和生物地理学角度对一个区域内物种的状况进行研究 ,也称区域物种多样性 ;二是指生态学方面物种分布的均匀程度 ,常常是从群落组织水平上进行研究 ,也称为生态多样性或群落多样性[1] 。本文所涉及物种多样性即为群落组织水平上的物种多样性。植物群落物种多样性的研究是其它多样性 (遗传多样性、生态系统多样性等 )的基础 ,有大量的研究成果相继报道 ,也有一些综述对植物群落物种多样性某一领域的研究进行总结。Ｍａｇｕ…     

Large‐scale dark diversity estimates: new perspectives with combined methods

Large‐scale biodiversity studies can be more informative if observed diversity in a study site is accompanied by dark diversity, the set of absent although ecologically suitable species. Dark diversity methodology is still being developed and a comparison of different approaches is needed. We used plant data at two different scales (European and seven large regions) and compared dark diversity estimates from two mathematical methods: species co‐occurrence (SCO) and species distribution modeling (SDM). We used plant distribution data from the Atlas Florae Europaeae (50 × 50 km grid cells) and seven different European regions (10 × 10 km grid cells). Dark diversity was estimated by SCO and SDM for both datasets. We examined the relationship between the dark diversity sizes (type II regression) and the overlap in species composition (overlap coefficient). We tested the overlap probability according to the hypergeometric distribution. We combined the estimates of the two methods to determine consensus dark diversity and composite dark diversity. We tested whether dark diversity and completeness of site diversity (log ratio of observed and dark diversity) are related to various natural and anthropogenic factors differently than simple observed diversity. Both methods provided similar dark diversity sizes and distribution patterns; dark diversity is greater in southern Europe. The regression line, however, deviated from a 1:1 relationship. The species composition overlap of two methods was about 75%, which is much greater than expected by chance. Both consensus and composite dark diversity estimates showed similar distribution patterns. Both dark diversity and completeness measures exhibit relationships to natural and anthropogenic factors different than those exhibited by observed richness. In summary, dark diversity revealed new biodiversity patterns which were not evident when only observed diversity was examined. A new perspective in dark diversity studies can incorporate a combination of methods.