中国菌食性管蓟马物种多样性及分布格局

菌食性管蓟马是土壤动物的重要组分, 它们在生物多样性保护与利用、植物保护、动物地理等领域具有重要的研究价值, 但在我国其分类和物种多样性研究仍有较大不足, 大尺度分布格局形成原因也不清楚。本文基于对我国大部分地区广泛的野外采集调查和国内外多家研究机构馆藏标本的检视, 整理了我国菌食性管蓟马物种名录和地理分布信息, 总结了我国菌食性管蓟马的分类研究现状与简史, 分析了菌食性管蓟马物种多样性的分布格局并探讨了该格局形成原因。目前我国记录菌食性管蓟马237种, 其中管蓟马亚科39属156种, 灵管蓟马亚科22属81种; 竹管蓟马属(Bamboosiella)、剪管蓟马属(Psalidothrips)、网管蓟马属(Apelaunothrips)和全管蓟马属(Holothrips)是物种较多的属, 包含物种数均超过10种; 中国特有73种; 广东、台湾、海南和云南是物种最丰富的省份, 均超过60种, 这些省份都具热带和亚热带气候特征, 适合其生存; 相对多度分析结果表明在热带和亚热带地区森林凋落物层菌食性管蓟马是土壤动物的常见类群; 气温、降水量、食物等是限制其分布的主要因素。本结果丰富了土壤生物多样性的研究内容, 为菌食性管蓟马多样性大尺度空间格局研究提供了数据支持。     

Australian Thysanoptera – biological diversity and a diversity of studies

Abstract   Studies in Australia on thrips have had extensive impacts worldwide. In behaviour, the latest definition of eusociality is derived from work on the radiation of thrips on Acacia species in central Australia, and these Acacia thrips also having been used to develop the concept of 'model clades' for analysing the evolution of behavioural and ecological diversity. In ecology, the concept of the lack of density dependent factors in population dynamics was elaborated through studies on the plague thrips of southern Australia. In virology, thrips were first shown in Australia to be the vectors of tospoviruses, although these viruses, their vectors and the plants attacked are all non-native to this continent. Work in Australia has included the development of electronic methods of illustration, identification and information transfer about thrips, including the use of molecular methods for pest species recognition, and considerable advances have been made in Australia in our knowledge of the relationships between thrips and plants, from polyphagy to pollination.     

Geographic patterns and environmental correlates of taxonomic and phylogenetic diversity of aquatic plants in China

Studies on large-scale geographic patterns of aquatic plant diversity can promote research on the generality of macroecological patterns in different ecosystems. Here, we compiled a checklist of 889 aquatic angiosperms in China, including 738 helophytes (emergent and marshy plants) and 151 hydrophytes (submerged, free-floating, and floating-leaved plants). We explore the geographic patterns and environmental correlates of aquatic plant diversity based on six metrics including species richness (SR), weighted endemism (WE), phylogenetic diversity (PD), phylogenetic endemism (PE), the standardized effect size of phylogenetic diversity (PDses), and the standardized effect size of mean phylogenetic distance (MPDses). Our results show that the diversity of aquatic plants in China is extremely uneven, with high diversity in southeastern China and low diversity in northwestern China, and the geographic patterns of taxonomic and PD are generally consistent. The pattern of helophytes differs from that of hydrophytes. Notably, the wavy-shaped pattern of aquatic plant diversity (especially SR and PD for hydrophytes) across the latitude observed in this study is not consistent with those previously observed for aquatic plants in other continents. Climatic variables and water environmental variables are the main drivers of aquatic plant diversity in China; however, the effects of individual variables differ between helophytes and hydrophytes. Water environmental variables have a greater impact on PDses and MPDses of hydrophytes than those of helophytes. Overall, our work provides insight into understanding the large-scale patterns of aquatic plant diversity and is a critical addition to previous studies on the macroecological pattern of terrestrial organisms.     

Phenological diversity in tropical forests

One of the most intriguing and complex characteristics of reproductive phenology in tropical forests is high diversity within and among forests. To understand such diversity, Newstrom et al. provided a systematic framework for the classification of tropical flowering phenology. They adopted frequency and regularity as criteria with priority, and classified plants in La Selva, Costa Rica, where most plants reproduced more than once a year irregularly. Many other studies have demonstrated annual cycles corresponding to rainfall patterns at the community level in Neotropical forests, including La Selva. On the other hand, supraannual flowering synchronized among various plant species, called general flowering, is known from aseasonal lowland dipterocarp forests in Southeast Asia. Within both forests, a wide spectrum of flowering patterns is found. This range of patterns suggests the great potential of tropical phenological studies to explore the selective pressures on phenology. Various abiotic and biotic factors can be selective agents. The shared pollinators hypothesis suggests that plant species sharing pollinators segregate flowering temporarily to minimize interspecific overlap in flowering times and thus minimize ineffective pollination or competition for pollinators, indicating strong phylogenetic constraints in timing and variation of flowering. Comparison of phenology within and among forests may help our understanding of phenological diversity. Attempts are now being made to develop a common language to communicate concepts and render interpretations of data more compatible among investigators and to create a network to promote comparative studies. Received: September 8, 2000 / Accepted: January 30, 2001     

Is population subdivision different from speciation? From phylogeography to species delimitation

Species‐level diversity and the underlying mechanisms that lead to the formation of new species, that is, speciation, have often been confounded with intraspecific diversity and population subdivision. The delineation between intraspecific and interspecific divergence processes has received much less attention than species delimitation. The ramifications of confounding speciation and population subdivision are that the term speciation has been used to describe many different biological divergence processes, rendering the results, or inferences, between studies incomparable. Phylogeographic studies have advanced our understanding of how spatial variation in the pattern of biodiversity can begin, become structured, and persist through time. Studies of species delimitation have further provided statistical and model‐based approaches to determine the phylogeographic entities that merit species status. However, without a proper understanding and delineation between the processes that generate and maintain intraspecific and interspecific diversity in a study system, the delimitation of species may still not be biologically and evolutionarily relevant. I argue that variation in the continuity of the divergence process among biological systems could be a key factor leading to the enduring contention in delineating divergence patterns, or species delimitation, meriting future comparative studies to help us better understand the nature of biological species.     

Fungal diversity from communities to genes

Fungi are hyperdiverse organisms and assemble in complex communities, characterized by high levels of species richness, turnover, and endemism. However, the origins and maintenance of such high diversity and the role environments play in fungal adaptation are still elusive. Traditionally, efforts to understand fungal diversity in their environment have been divided between studies at the species level and below species level, with separate disciplines such as community ecology and population genetics working independently and with little communication. Here I argue that linking these different approaches is required to fully document the diversity of fungi in nature. Understanding the patterns and mechanisms of fungal diversity and composition requires not only the study of species assemblies and ranges, but also relies on comprehending fungal intra-specific variation, dispersal and establishment, including identifying key traits influencing fitness. This implies better integration and cross-fertilization between disciplines addressing fungi at a multitude of biological levels, ranging from genes to whole communities. Such approach will yield direct links between variation, adaptation and environments and provide a much more comprehensive understanding of fungal diversity.     

Life‐history syndromes: Integrating dispersal through space and time

Recent research has highlighted interdependencies between dispersal and other life‐history traits, i.e. dispersal syndromes, thereby revealing constraints on the evolution of dispersal and opportunities for improved ability to predict dispersal by considering suites of dispersal‐related traits. This review adds to the growing list of life‐history traits linked to spatial dispersal by emphasising the interdependence between dispersal through space and time, i.e. life‐history diversity that distributes individuals into separate reproductive events. We reviewed the literature that has simultaneously investigated spatial and temporal dispersal to examine the prediction that traits of these two dispersal strategies are negatively correlated. Our results suggest that negative covariation is widely anticipated from theory. Empirical studies often reported evidence of weak negative covariation, although more complicated patterns were also evident, including across levels of biological organisation. Existing literature has largely focused on plants with dormancy capability, one or two phases of the dispersal process (emigration and/or transfer) and a single level of biological organisation (theory: individual; empirical: species). We highlight patterns of covariation across levels of organisation and conclude with a discussion of the consequences of dispersal through space and time and future research areas that should improve our understanding of dispersal‐related life‐history syndromes.     

An ecological perspective on bacterial biodiversity

Bacteria may be one of the most abundant and species-rich groups of organisms, and they mediate many critical ecosystem processes. Despite the ecological importance of bacteria, past practical and theoretical constraints have limited our ability to document patterns of bacterial diversity and to understand the processes that determine these patterns. However, recent advances in molecular techniques that allow more thorough detection of bacteria in nature have made it possible to examine such patterns and processes. Here, we review recent studies of the distribution of free-living bacterial diversity and compare our current understanding with what is known about patterns in plant and animal diversity. From these recent studies a preliminary picture is emerging: bacterial diversity may exhibit regular patterns, and in some cases these patterns may be qualitatively similar to those observed for plants and animals.     

Understanding biodiversity effects on prey in multi-enemy systems

Biodiversity–ecosystem functioning theory would predict that increasing natural enemy richness should enhance prey consumption rate due to functional complementarity of enemy species. However, several studies show that ecological interactions among natural enemies may result in complex effects of enemy diversity on prey consumption. Therefore, the challenge in understanding natural enemy diversity effects is to predict consumption rates of multiple enemies taking into account effects arising from patterns of prey use together with species interactions. Here, we show how complementary and redundant prey use patterns result in additive and saturating effects, respectively, and how ecological interactions such as phenotypic niche shifts, synergy and intraguild predation enlarge the range of outcomes to include null, synergistic and antagonistic effects. This study provides a simple theoretical framework that can be applied to experimental studies to infer the biological mechanisms underlying natural enemy diversity effects on prey.     

Leaf morphology of hosts and nonhosts of the thrips Heliothrips haemorrhoidalis (Bouché)

This study highlights the morphological differences between two groups of plants; those that are recorded as hosts of the thrips Heliothrips haemorrhoidalis (Bouché) and those that remain free from infestation. Scanning electron microscope techniques were used to describe the morphology of the leaf surface of 19 species in order to help identify which morphological features could play a role in the selection of plant species by thrips from among a diverse botanical collection. H. haemorrhoidalis had a preference for species with leaves that were coriaceous, with one or both surfaces being smooth. Plants evading these thrips commonly possessed glandular trichomes. Thus morphology may have a role in deterring thrips from the leaf surface, as well as influencing the behaviour of predators that control thrips. Further detailed studies into the chemistry of leaves of hosts and nonhost species may help to further our understanding of selection mechanisms.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 152 , 109–130.     

Diversity patterns of cushion plants on the Qinghai-Tibet Plateau: A basic study for future conservation efforts on alpine ecosystems

The Qinghai-Tibet Plateau (QTP) is an important cushion plant hotspot. However, the distribution of cushion plants on the QTP is unknown, as are the factors that drive cushion plant distribution, limiting our understanding of the evolution of cushion species in the region. In this study, we assessed spatial patterns of total cushion plant diversity (including taxonomic and phylogenetic) over the entire QTP and compared patterns of diversity of cushion plants with different typologies (i.e., compact vs. loose). We also examined how these patterns were related to climatic features. Our results indicate that the southern QTP hosts the highest total cushion plant richness, especially in the south-central Hengduan Mountains subregion. The total number of cushion species declines from south to north and from southeast to northwest. Compact cushion plants exhibit similar patterns as the total cushion plant richness, whereas loose cushion plants show random distribution. Cushion plant phylogenetic diversity showed a similar pattern as that of the total cushion plant richness. In addition, cushion plant phylogenetic community structure was clustered in the eastern and southwestern QTP, whereas random or overdispersed in other areas. Climatic features represented by annual energy and water trends, seasonality and extreme environmental factors, had significant effects on cushion plant diversity patterns but limited effects on the phylogenetic community structure, suggesting that climatic features indeed promote the formation of cushion plants. Because cushion plants play vital roles in alpine ecosystems, our findings not only promote our understanding of the evolution and formation of alpine cushion plant diversity but also provide an indispensable foundation for future studies on cushion plant functions and thus alpine ecosystem sustainability in the entire QTP region.     

微生物多样性及其分布的研究进展:模式与过程

生物多样性产生和维持机制长期以来是生态学研究的核心问题。人们通过实验观察和理论推导揭示了很多群落生物多样性的共有模式及其背后的生态学过程,而相关的工作主要集中在动植物等大型生物中。微生物是地球上数量最多、分布最广,以及在生态系统过程中发挥极其重要作用的生物类群,但人们对其群落多样性的认识还非常有限。将介绍目前人们对能够独立自由生活的微生物多样性分布模式的探索,总结对其背后的生物学和生态学过程的研究现状,并探讨当前面临的挑战。     

Uniting species- and community-oriented approaches to understand arbuscular mycorrhizal fungal diversity

Arbuscular mycorrhizal fungi (AMF) occur in the majority of terrestrial, and some aquatic, habitats worldwide. They are important for the functioning of individual plants and of entire ecosystems. Here, we review trends in research on species- (species recognition, phylogenetic relationships, autecology) and community-level AMF diversity patterns and aim to identify ways of improving the complementarity of these approaches. Research into many aspects of AMF diversity has flourished in parallel with the increasing availability of molecular biology techniques. However, despite their shared goal of understanding AMF biodiversity, species- and community-level perspectives, and the morphological and molecular approaches that underpin them, currently have limited capacity for information exchange. We indicate critical research gaps in AMF species and community characterisation and outline important research directions. We propose steps that could link research using different methods and targeting different aspects of diversity, in order to maximise our understanding of AMF.     

Altitude effects on spatial components of vascular plant diversity in a subarctic mountain tundra

Environmental gradients are caused by gradual changes in abiotic factors, which affect species abundances and distributions, and are important for the spatial distribution of biodiversity. One prominent environmental gradient is the altitude gradient. Understanding ecological processes associated with altitude gradients may help us to understand the possible effects climate change could have on species communities. We quantified vegetation cover, species richness, species evenness, beta diversity, and spatial patterns of community structure of vascular plants along altitude gradients in a subarctic mountain tundra in northern Sweden. Vascular plant cover and plant species richness showed unimodal relationships with altitude. However, species evenness did not change with altitude, suggesting that no individual species became dominant when species richness declined. Beta diversity also showed a unimodal relationship with altitude, but only for an intermediate spatial scale of 1 km. A lack of relationships with altitude for either patch or landscape scales suggests that any altitude effects on plant spatial heterogeneity occurred on scales larger than individual patches but were not effective across the whole landscape. We observed both nested and modular patterns of community structures, but only the modular patterns corresponded with altitude. Our observations point to biotic regulations of plant communities at high altitudes, but we found both scale dependencies and inconsistent magnitude of the effects of altitude on different diversity components. We urge for further studies evaluating how different factors influence plant communities in high altitude and high latitude environments, as well as studies identifying scale and context dependencies in any such influences.     

Octothrips lygodii sp. n. (Thysanoptera: Thripidae) damaging weedy Lygodium ferns in south-eastern Asia, with notes on other Thripidae reported from ferns

Abstract Weedy Lygodium ferns have become a serious fire hazard in Florida, introduced from the Old World Tropics. During joint CSIRO/USDA studies on potential biological control agents, a thrips species was found widely in south-eastern Asia causing severe damage to L. microphyllum . Described here as a new species, Octothrips lygodii , this is the second species of a poorly known genus that has been based on a single damaged male from Papua New Guinea. The genus is redefined, the two species distinguished, and notes given on the range of Thripidae reported from ferns worldwide.     

Sensitivity of flowering plant gametophytes to temperature fluctuations

Research on plant responses to temperature stress is receiving increased interest due to the growing awareness about global warming. High and low temperature stresses help establish the narrow geographic distribution of some cultivated plants, the limited geographic extension of some other economically nutritionally important species, and also induce irregular bearing for some species. However, the understanding of plant responses to temperature stress lags behind other biotic and abiotic stresses probably due to the complex response at the molecular, cellular, and organismal level. Temperature stress affects, indeed, many developmental processes during the plant's life cycle. However, the reproductive stage, the outcome of which represents the economic value for many cultivated plants, is especially vulnerable. Here the effect of low and high temperature stresses during the flowering phase is reviewed in flowering plants in an attempt to unravel sensitive stages that are behind irregular cropping. The review presents detailed findings from 33 previously published reports spanning 19 different flowering plant species. Both the male and female organs of the flower are especially sensitive to temperature fluctuations both during their development before pollination and during the post-pollination stage. The effect of temperature stress is, however, obscured by the complex male–female interaction superimposed on the individual behavior of each organ. Interestingly, a review of the literature on this topic shows that genetic variation does exist in reproductive behavior under temperature fluctuations. This genetic diversity must be preserved and characterized in further detail to understand how plants naturally cope with changing environmental conditions, which will, undoubtedly, help us to design better strategies to face current and future challenging temperature fluctuations.     

Persistence and stochasticity are key determinants of genetic diversity in plants associated with banded iron formation inselbergs

The high species endemism characteristic of many of the world's terrestrial island systems provides a model for studying evolutionary patterns and processes, yet there has been no synthesis of studies to provide a systematic evaluation of terrestrial island systems in this context. The banded iron formations (BIFs) of south‐western Australia are ancient terrestrial island formations occurring within a mosaic of alluvial clay soils, sandplains and occasional granite outcropping, across an old, gently undulating, highly weathered, plateau. Notably, these BIFs display exceptionally high beta plant diversity. Here, we address the determinants and consequences of genetic diversity for BIF‐associated plant species through a comprehensive review of all studies on species distribution modelling, phylogenetics, phylogeography, population genetics, life‐history traits and ecology. The taxa studied are predominantly narrowly endemic to individual or a few BIF ranges, but some have more regional distributions occurring both on and off BIFs. We compared genetic data for these BIF‐endemic species to other localised species globally to assess whether the unique history and ancestry of BIF landscapes has driven distinct genetic responses in plants restricted to this habitat. We also assessed the influence of life‐history parameters on patterns of genetic diversity. We found that BIF‐endemic species display similar patterns of genetic diversity and structure to other species with localised distributions. Despite often highly restricted distributions, large effective population size or clonal reproduction appears to provide these BIF‐endemic species with ecological and evolutionary resilience to environmental stochasticity. We conclude that persistence and stochasticity are key determinants of genetic diversity and its spatial structure within BIF‐associated plant species, and that these are key evolutionary processes that should be considered in understanding the biogeography of inselbergs worldwide.     

盆栽榕树蓟马种类及优势种榕管蓟马对寄主植物的致害性

为明确盆栽榕树蓟马的种类, 了解蓟马优势种对在同一温室内混合种植的榕属及非榕属盆栽植物的致害性差异, 以福建漳州、 福州和泉州等地的盆栽榕树种植基地为观测点, 采集榕树叶片, 调查蓟马种类, 确定优势种蓟马; 以天南星科喜林芋属、 紫葳科菜豆树属、 木棉科瓜栗属和桑科榕属等不同科属盆栽植物为试验材料, 测试榕管蓟马Gynaikothrips uzeli Zimmerman对寄主植物的致害性。结果表明： 盆栽榕树蓟马种类有2亚目, 2科, 8属, 9种, 优势种为榕管蓟马, 常见种为棘腿管蓟马Androthrips ramachandrai Karny和榕腿管蓟马Mesothrips jordani Zimmermann, 其他6种蓟马均为偶见种。榕管蓟马对不同寄主植物的致害性差异显著, 以对桑科榕属植物致害性为最强, 而对天南星科喜林芋属、 紫葳科菜豆树属和木棉科瓜栗属等其他植物的致害性较弱。在6种榕属植物中, 榕管蓟马对垂叶榕Ficus benjamina Linn.、 榕树F. microcarpa Linn. f.、 花叶垂叶榕F. benjamina cv. Golden Princess等3种榕属植物的为害等级均达3级以上, 以垂叶榕最重, 榕树次之, 花叶垂叶榕略轻; 对金叶榕F. microcarpa cv. Golden Leaves、 黑叶橡胶榕F. elastica cv. Deocora Burgundy、 斑叶橡胶榕F. elastica var. variegata等3种榕属植物的为害很轻, 为害等级均仅为1级; 同时, 榕管蓟马在金叶榕、 黑叶橡胶榕和斑叶橡胶榕上繁殖力弱、 无法完成世代, 而在榕树、 垂叶榕和花叶垂叶榕上繁殖力强、 能完成世代, 但以在垂叶榕上的发育情况最好。研究可为选择利用寄主植物抗虫性来有效防控盆栽榕树蓟马提供技术支撑。