Biodiversity Dynamics Research Articles

SRUD: A simple non‐destructive method for accurate quantification of plant diversity dynamics

Abstract Predicting changes in plant diversity in response to human activities represents one of the major challenges facing ecologists and land managers striving for sustainable ecosystem management. Classical field studies have emphasized the importance of community primary productivity in regulating changes in plant species richness. However, experimental studies have yielded inconsistent empirical evidence, suggesting that primary productivity is not the sole determinant of plant diversity. Recent work has shown that more accurate predictions of changes in species diversity can be achieved by combining measures of species’ cover and height into an index of space resource utilization (SRU). While the SRU approach provides reliable predictions, it is time‐consuming and requires extensive taxonomic expertise. Ecosystem processes and plant community structure are likely driven primarily by dominant species (mass ratio effect). Within communities, it is likely that dominant and rare species have opposite contributions to overall biodiversity trends. We, therefore, suggest that better species richness predictions can be achieved by utilizing SRU assessments of only the dominant species (SRUD), as compared to SRU or biomass of the entire community. Here, we assess the ability of these measures to predict changes in plant diversity as driven by nutrient addition and herbivore exclusion. First, we tested our hypotheses by carrying out a detailed analysis in an alpine grassland that measured all species within the community. Next, we assessed the broader applicability of our approach by measuring the first three dominant species for five additional experimental grassland sites across a wide geographic and habitat range. We show that SRUD outperforms community biomass, as well as community SRU, in predicting biodiversity dynamics in response to nutrients and herbivores in an alpine grassland. Across our additional sites, SRUD yielded far better predictions of changes in species richness than community biomass, demonstrating the robustness and generalizable nature of this approach. Synthesis. The SRUD approach provides a simple, non‐destructive and more accurate means to monitor and predict the impact of global change drivers and management interventions on plant communities, thereby facilitating efforts to maintain and recover plant diversity.

Unravelling the history of biodiversity in mountain ranges through integrating geology and biogeography

AbstractAimWe advocate an interdisciplinary approach to biogeography, integrating geology and paleobiology to examine how biodiversity dynamics evolved as mountain ranges formed through (geological) time.LocationGlobal; case study: Anatolia (Turkey).MethodsWe discuss the links between surface uplift and biodiversity dynamics and review recent developments for reconstructing the history of geography and biodiversity. To illustrate an integrative approach to biogeography, we present a case study of Neogene Anatolia. In particular, we reconstruct Anatolian paleogeography based on a synthesis of both quantitative and qualitative evidence, and review the fossil record of the regional flora and fauna, to identify changes in compositions that might be induced by surface uplift and associated environmental changes.ResultsThe Central Anatolian Plateau and its mountainous margins display different histories of surface uplift during the late Miocene to Pliocene, which are detectable in the regional fossil record of large mammals. Overall changes in vegetation and climatic conditions for the whole region also align with the general time frame of surface uplift.Main conclusionsOur discussion and case study highlight the value of an integrative biogeographic framework, by combining knowledge and techniques from geology and paleobiology to simultaneously consider the biotic and environmental dynamics in space and time. Neogene surface uplift in Anatolia has affected the regional biota, particularly the diversity of plants and large mammals, along with well‐known global and regional changes in climate and other environmental factors. To disentangle the effects of different, but most likely interactive environmental changes at various scales, we call for rigorous examination of the geological record in a biogeographic framework, using innovative methods to uncover how environmental and biotic processes have shaped mountain biodiversity.

TYPOLOGY OF THE ENTOMOLOGICAL COMPLEX OF DENDROBINOTS IN NATURAL AND SEMI-NATURAL BIOCOENOSIS OF CHERNIHIV REGION

This article is devoted to study typology of the entomological complex in natural and semi-natural natural biocensosis of Chernihiv region. Nowadays, the threat of significant reduction of biodiversity as a result of some types of human activity has led to recognition not only of the concept of «biodiversity», but also as a global object of protection. This led to the formation of a new approach to nature conservation, which, in turn, requires the development of plans and strategies for the conservation of biological diversity.In this regard, the methods of studying biodiversity, in particular its quantitative evaluation, have become particularly important. The issue of biodiversity conservation today has a high relevance to society, it affects socio-cultural, economic factors and factors of the environment. A rapid increase in the population of the planet dictates its laws, so it is necessary to comprehensively consider all possible options for increasing food production.All domesticated crops and animals are derived from the human management of biodiversity, which consistently responds to the peculiarities of agricultural production. It is biodiversity that provides natural management of pests, reducing the use of pesticides, obtaining high yields of cereal crops due to natural pollinators. Domestic and wild varieties of animals and plants are mandatory sources of genetic variability to respond to abiotic and biotic factors through population-genetic adaptation. In this article was established that the main cause of impoverishment of biodiversity is anthropogenic impact of the environment and intensive consumption of natural resources. It is substantiated that to solve the problems associated with preservation. Biodiversity, in particular, the species diversity of insects, is necessary first of all to solve the problem of preservation and protection of habitats of their existence (skirt, lawns, roadsides, slopes of beams, ravines, fallow, etc.). However, the optimal size of these seminatural biotopes is not sufficiently researched so it is extremely important to implement conservation measures for agrobiodiversity. Exhausting use of natural resources is today the main form of their use in agriculture. Therefore, the issue of conservation, non-exhaustive use and reproduction of biodiversity is attracting increasing attention and is absolutely topical. The purpose of the work was to study the typology and dynamics of species entomological biodiversity in the natural and semi-natural biocenoses of the Chirniv region.

Maximizing habitat connectivity in the mitigation hierarchy. A case study on three terrestrial mammals in an urban environment

Environmental policies and the objective of no net loss highlight the importance of preserving ecological networks to limit the fragmentation of natural habitats and biodiversity loss, especially due to urbanization. In the environmental impact assessment context, habitat connectivity and the spatio-temporal dynamics of biodiversity are crucial to obtaining reliable predictions that can support decision-making. We propose a methodological framework 1) to quantify the overall impact of a development project on the functioning of an ecological network, and 2) to select the best locations for implanting new habitat patches intended to enhance landscape connectivity. The amount of reachable habitat concept was applied to three representative terrestrial mammal species: the red squirrel, the Eurasian badger and the European hedgehog. All three species are recognized as vulnerable to human pressures and potentially affected by the construction of a new stadium in our study site, Lyon (Southern France). The method combines the species distribution model Maxent with the landscape functional connectivity model Graphab. The results showed that using any one of the avoidance and reduction measures on its own was unsuccessful in achieving the objective of no net loss when habitat connectivity is considered. However, the combination of new habitat patches and corridors offered a higher gain than distinct measures. This is especially important in the short term, when new hedgerow plantations have not yet developed enough to be used by the target species. Our findings indicate, first, the need to take the temporal scale into account in environmental impact assessment. We also show that applying the optimal scenario, constructed using a cumulative patch addition followed by a similar process testing a set of potential land-use changes, maximizes habitat connectivity. Our methodology provides a useful tool to increase target species’ habitat connectivity within the mitigation hierarchy and to enhance development project design for increased environmental efficiency.

Interactions between ecological, evolutionary and environmental processes unveil complex dynamics of insular plant diversity

AbstractAimsUnderstanding how biodiversity emerges and how it varies in space and time requires integration of the underlying processes that affect biodiversity at different levels of ecological organization. We present BioGEEM (BioGeographical Eco‐Evolutionary Model), a spatially explicit model that integrates theories and processes understood to drive biodiversity dynamics. We investigated the necessary degree of mechanistic complexity by exploring simulation experiments to evaluate the relative roles of the underlying processes across spatio‐temporal scales and ecological levels (e.g. populations, species, communities).LocationHypothetical oceanic islands.MethodsBioGEEM is stochastic and grid‐based, and it integrates ecological (metabolic constraints, demography, dispersal and competition), evolutionary (mutation and speciation) and environmental (geo‐climatic dynamics) processes. Plants on oceanic islands served as a model system. We ran the simulations both with all processes on and with selected processes switched off to assess the role of each process from the emergent patterns.ResultsThe full model was able to generate patterns matching empirical evidence and theoretical expectations. Population sizes were largest on young islands, and species, particularly endemics, better filled their potential range on young and old islands due to limited area and reduced competition. Richness peaked at mid‐elevations. The proportion of endemics was highest in old, large and isolated environments within the islands. Species and trait richness showed unimodal temporal trends. Switching off selected processes led to several unrealistic patterns, including the evolution of super‐dominant species, extremely high richness and weakened spatial diversity gradients.Main conclusionsThe main predictions derived from BioGEEM are: Competition has cross‐scale effects on diversity. Hump‐shaped temporal dynamics can be obtained without speciation. Endemic species seem less susceptible to extinction than native non‐endemic species. Endemism reflects stronger geographical and environmental isolation. Finally, only the integration of all implemented processes generates realistic spatio‐temporal dynamics at population, species, community and assemblage levels.

Text-mined fossil biodiversity dynamics using machine learning.

Documented occurrences of fossil taxa are the empirical foundation for understanding large-scale biodiversity changes and evolutionary dynamics in deep time. The fossil record contains vast amounts of understudied taxa. Yet the compilation of huge volumes of data remains a labour-intensive impediment to a more complete understanding of Earth's biodiversity history. Even so, many occurrence records of species and genera in these taxa can be uncovered in the palaeontological literature. Here, we extract observations of fossils and their inferred ages from unstructured text in books and scientific articles using machine-learning approaches. We use Bryozoa, a group of marine invertebrates with a rich fossil record, as a case study. Building on recent advances in computational linguistics, we develop a pipeline to recognize taxonomic names and geologic time intervals in published literature and use supervised learning to machine-read whether the species in question occurred in a given age interval. Intermediate machine error rates appear comparable to human error rates in a simple trial, and resulting genus richness curves capture the main features of published fossil diversity studies of bryozoans. We believe our automated pipeline, that greatly reduced the time required to compile our dataset, can help others compile similar data for other taxa.

Long-term dynamics of natural biodiversity of Ukraine by the «living planet» indicator

Biodiversity is of vital importance for supporting environmental processes and is currently considered as the main parameter characterizing the state of the ecological systems. The main component of the global strategy for the conservation of biodiversity is the creation of protected areas. At present, their total area is about 12% of the Earth’s surface, but quantitative estimates of the positive environmental impact of such areas on the state of biodiversity have not been sufficiently studied today. To analyze the long-term dynamics of biodiversity in Ukraine according to the «living planet» index is done. The value of the index was determined by the method as the average of the indexes of all populations included in the calculation, for each time interval and treated statistically. Global Biodiversity Indicator — the Living Planet Index (LPI) has been widely used to monitor the dynamics of biota. Under conditions when the biological monitoring system has not yet been established in Ukraine, the results of the annual calculation of the number of wildlife and bird populations (data are summarized in the state statistical report «Basic Indicators of Hunting Management») — the only available information on the state of biota populations. As a result of our calculations and analysis of the natural course of indicators of LPI, it has been established that a national strategy for the conservation of biodiversity by increasing the territory of the nature reserve fund contributes to a positive ecological effect. Unlike the findings of the experts of the «World Wildlife Fund», for the last 28 years of observation, the «living planet»index in Ukraine does not show the impoverishment of vertebrate biodiversity.

Macroevolutionary diversification rates show time dependency

For centuries, biologists have been captivated by the vast disparity in species richness between different groups of organisms. Variation in diversity is widely attributed to differences between groups in how fast they speciate or go extinct. Such macroevolutionary rates have been estimated for thousands of groups and have been correlated with an incredible variety of organismal traits. Here we analyze a large collection of phylogenetic trees and fossil time series and describe a hidden generality among these seemingly idiosyncratic results: speciation and extinction rates follow a scaling law in which both depend on the age of the group in which they are measured, with the fastest rates in the youngest clades. Using a series of simulations and sensitivity analyses, we demonstrate that the time dependency is unlikely to be a result of simple statistical artifacts. As such, this time scaling is likely a genuine feature of the tree of life, hinting that the dynamics of biodiversity over deep time may be driven in part by surprisingly simple and general principles.

Disentangling the processes driving tree community assembly in a tropical biodiversity hotspot (New Caledonia)

AbstractAimUnderstanding the drivers of community diversity and composition is a major question in ecology, which is of particular significance for the conservation of narrowly distributed taxa facing habitat alteration. In this study, we examined three ecological processes (environmental and biotic filtering, and dispersal limitation) hypothesized to drive community assembly in the island biodiversity hotspot of New Caledonia, and whether the relative importance of these processes changes along environmental gradients.MethodsFirst, we assessed environmental filtering by stacking binary presence/absence species distribution models generated for 678 tree species from c. 40,000 occurrences. Second, we acknowledged the influence of dispersal limitation by applying a buffer around each occurrence. Third, we modelled a local hierarchy of performances by ranking species in decreasing order of their predicted habitat suitability, up to the predicted local species richness. Predictions of stacked species distribution models (S‐SDMs) accounting for different combinations of the filtering processes were compared with the composition of 12 forest plots.ResultsThe three filters appear to be important driving forces. Accounting for environmental filtering provided fairly accurate assemblage predictions but species richness was overestimated. Considering dispersal limitation increased assemblage specificity (the proportion of correctly predicted absences) while considering differences in local performances increased assemblage sensitivity (the proportion of correctly predicted presences). The predictive ability of all S‐SDMs decreased with elevation, which suggests that unpredictable stochastic processes influenced biodiversity dynamics in more productive mountain habitats.Main conclusionsNew Caledonian tree communities appear to be similar to those of other tropical regions in their structuring processes (important role of dispersal and biotic filtering, increasing role of neutral processes with productivity). Our findings stress the potential of using S‐SDMs to understand and predict current and future biodiversity patterns.

Evolution of the latitudinal diversity gradient in the hyperdiverse ant genus Pheidole

AbstractAimThe latitudinal diversity gradient is the dominant geographic pattern of life on Earth, but a consensus understanding of its origins has remained elusive. The analysis of recently diverged, hyper‐rich invertebrate groups provides an opportunity to investigate latitudinal patterns with the statistical power of large trees while minimizing potentially confounding variation in ecology and history. Here, we synthesize global phylogenetic and macroecological data on a hyperdiverse (> 1,100 species) ant radiation, Pheidole and test predictions of three general explanations for the latitudinal gradient: variation in diversification rates, tropical conservatism and ecological regulation.LocationGlobal.Time periodThe past 35 million years.Major taxa studiedThe hyperdiverse ant genus Pheidole Westwood.MethodsWe assembled geographic data for 1,499 species and morphospecies, and inferred a dated phylogeny for 449 species of Pheidole, including 167 species newly sequenced for this study. We tested for correlations between diversification rate and latitude with Bayesian analysis of macroevolutionary mixtures (BAMM), hidden state speciation and extinction (HiSSE), geographic state speciation and extinction (GeoSSE), and a non‐parametric method (FiSSE), evaluated evidence for richness steady state, and examined patterns of diversification as Pheidole spread around the globe.ResultsThere was no evidence of systematic variation of net diversification rates with latitude across any of the methods. We found that Pheidole diversification occurred in bursts when new continents were colonized, followed by a slowdown in each region, but there is no evidence richness has saturated at an equilibrium in any region. Additionally, we found latitudinal affinity is moderately conserved with a Neotropical ancestor and simulations show that phylogenetic inertia alone is sufficient to produce the gradient pattern.Main conclusionsOur results provide no evidence that diversification rates vary systematically with latitude. Richness is far from steady state in each region, contrary to the ecological regulation hypothesis, although there is evidence that ecological opportunity promotes diversification after colonization of new areas. The fact that niche conservatism is strong enough to produce the gradient pattern is in accord with the tropical conservatism hypothesis. Overall, these results shed light on the mechanisms underlying the emergence of the diversity gradient within the past 34 million years, complementing recent work on deeper time‐scales, and more generally contribute toward much‐needed invertebrate perspective on global biodiversity dynamics.

Seasonal dynamics of the coastal bacterioplankton at intensive fish-farming areas of the Yellow Sea, China revealed by high-throughput sequencing

Marine aquaculture areas are facing stressed environmental challenges, especially the degradation of coastal ecosystems. Here a coordinated time-series study was used to investigate the coastal bacterioplankton biodiversity dynamics of the Yellow Sea, China. Bacterial 16S rRNA gene sequencing revealed a temporal pattern of decreasing of diversity in summer. Functional prediction indicated that metabolic pathways related to the adenosine triphosphate (ATP)-binding cassette transporters and other membrane transporters were significantly enriched in May, while the genetic information processing category was most abundant in March. The May microbiomes showed most significant positive correlation with phosphate concentration, while the August and November microbiomes correlated with temperature and chemical oxygen demand (COD) most, and the March microbiomes showed significant correlation with Cu2+ level, pH and salinity. The correlations between representative bacteria and environmental parameters revealed in this study may provide insights into the potential influences of human aquaculture activities, on the biodiversity of coastal bacterioplankton.

Main trends of biodiversity dynamics after natural and anthropogenic "catastrophes" in spruce forests of the European part of Russia

We analyzed the main trends of the change in the species richness of phytocenoses after catastrophic natural (beetle outbreaks, windfalls) and anthropogenic (clear cutting) disturbances. We examined the dynamics of the structural diversity of species richness of herb-dwarf scrubs layer with different reforestation technologies after the death of spruce stands. The study of similarity and ordination of vegetation showed the proximity of the undamaged forest to the unharvested stand, and the difference of these phytocenoses from clear-cut. The main determining factor of species richness was the intensity of phytocenosis disturbance after catastrophes. The reforestation dynamics of phytocenoses after catastrophic disturbances were analyzed. Clear cutting led to the formation of meadow communities with a sharp increase in the species and structural diversity of phytocenoses.

Whole-genome sequencing of an extinct whitefish species reveals extensive introgression after speciation reversal

Event Abstract Back to Event Whole-genome sequencing of an extinct whitefish species reveals extensive introgression after speciation reversal David F. Frei1, 2*, Ole Seehausen1, 2 and Philine G. Feulner1, 2 1 Swiss Federal Institute of Aquatic Science and Technology, Switzerland 2 University of Bern, Switzerland A large proportion of contemporary biodiversity evolved through ecological speciation, which is the evolution of reproductive isolation as a consequence of adaptation to divergent selection between niches. If species evolved in response to divergent ecological selection, a change in the balance between gene flow and selection can erode reproductive isolation and lead to speciation reversal. Although a major part of the world’s species diversity is sensitive to hybridization-driven biodiversity dynamics, the concept of speciation reversal has received little attention. In Switzerland, cultural eutrophication of pre-alpine lakes caused a substantial loss of endemic whitefish diversity by a combination of speciation reversal and demographic decline. We made use of a collection of historical whitefish scales as source of DNA to sequence whole-genomes of the pre-eutrophication populations of endemic Lake Constance whitefish species, including the profundal Coregonus gutturosus that went extinct during eutrophication. We found significant introgression of the extinct species into three contemporary species that happened during the eutrophic phase, demonstrating the involvement of speciation reversal in the extinction process of C. gutturosus. We identified introgressed regions and show the genomic landscape of introgression after speciation reversal in genomes of extant whitefish species. In total, we detected a proportion of 11% of the genome of C. gutturosus distributed across six genomes of contemporary species, suggesting that introgression rescued considerable amounts of genetic variation of the extinct species from being lost. Currently, we are investigating whether this variation contains genes that may play a role in future adaptation to profundal habitats that currently have no whitefish anymore, although they can be occupied again due to recent re-oligotrophication. As a large fraction of contemporary biodiversity evolved through ecological speciation, the potential for speciation reversal when environments change is widespread. Our results highlight the importance of the conservation of ecological and evolutionary mechanisms maintaining species diversity and advance our understanding of speciation reversal as one evolutionary trajectory that lineages can follow through time. Acknowledgements We thank Eawag and the interreg project "SeeWandel: Leben im Bodensee – gestern, heute und morgen" for financial support. Thanks to the genetic diversity center (GDC) of ETH Zurich, Eawag and the University of Bern for providing the infrastructure and support to analyze our data. Keywords: ecological speciation, speciation reversal, Alpine whitefish, Introgression, Eutrophication Conference: XVI European Congress of Ichthyology, Lausanne, Switzerland, 2 Sep - 6 Sep, 2019. Presentation Type: Oral Topic: EVOLUTIONARY GENOMICS OF FISHES Citation: Frei DF, Seehausen O and Feulner PG (2019). Whole-genome sequencing of an extinct whitefish species reveals extensive introgression after speciation reversal. Front. Mar. Sci. Conference Abstract: XVI European Congress of Ichthyology. doi: 10.3389/conf.fmars.2019.07.00041 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 20 May 2019; Published Online: 14 Aug 2019. * Correspondence: Mr. David F Frei, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland, david.frei@eawag.ch Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers David F Frei Ole Seehausen Philine G Feulner Google David F Frei Ole Seehausen Philine G Feulner Google Scholar David F Frei Ole Seehausen Philine G Feulner PubMed David F Frei Ole Seehausen Philine G Feulner Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Fish biodiversity dynamics in the Western part of Lake Balkash (Central Asia)

Fish biodiversity dynamics in the Western part of Lake Balkash (Central Asia)

沙尘暴对北京市空气细菌多样性特征的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 沙尘暴对北京市空气细菌多样性特征的影响 DOI: 10.5846/stxb201803260610 作者: 作者单位: 中国科学院生态环境研究中心 城市与区域生态国家重点实验室,中国科学院生态环境研究中心 城市与区域生态国家重点实验室,中国科学院生态环境研究中心 城市与区域生态国家重点实验室,浙江工商大学 环境科学与工程学院,中国科学院生态环境研究中心 城市与区域生态国家重点实验室 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金重点项目（71533005）；浙江省自然科学基金项目（LY17D050006） Effects of sandstorms on the diversity characteristics of airborne bacteria in Beijing Author: Affiliation: State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences,,,,Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:亚洲沙尘暴携带着各类污染物质，严重影响下风向地区大气过程及生态系统和相关人群的健康。然而，沙尘天气对中国华北地区空气细菌群落及多样性特征影响的研究较少。以北京市为例，系统研究了沙尘暴对城市空气细菌多样性特征的影响。2015年4月，通过定点采样连续收集了一次沙尘暴及其前后4天的空气颗粒物样本，DNA提取、PCR扩增后进行16S rRNA基因高通量测序。共获得169122条高质量序列，生物信息学分析表明，北京市空气细菌物种多样性较高，沙尘暴不能引起细菌OTU数目的增加，但沙尘暴天气下细菌群落Pielou、Shannon和Simpson指数显著增加。菌群分类分析发现，北京市空气细菌由35个细菌门构成，其中变形菌门（Proteobacteria）、放线菌门（Actinobacteria）、厚壁菌门（Firmicutes）和拟杆菌门（Bacteroidetes）相对丰度最高，分别占总序列的32.76%、28.09%、25.46%和6.32%；芽单胞菌门（Gemmatimonadetes）和酸杆菌门（Acidobacteria）次之，分别占序列总数的2.11%和1.81%，其他细菌门的相对丰度均低于1%。沙尘暴天气下，变形菌门（Proteobacteria）、拟杆菌门（Bacteroidetes）、芽单胞菌门（Gemmatimonadetes）和酸杆菌门（Acidobacteria）显著升高（P < 0.05），分别由31.67%、5.74%、1.82%、1.51%升高至41.46%、10.98%、4.48%和4.26%；而放线菌门（Actinobacteria）、厚壁菌门（Firmicutes）显著降低（P < 0.05），分别由28.84%、27.10%降低至22.13%和12.35%。冷杆菌属（Psychrobacter），纤维单胞菌属（Cellulomonas），不动杆菌属（Acinetobacter），假单胞菌属（Pseudomonas）和梭菌属（Clostridium）可能含有人类条件病原菌，其在沙尘暴天气中相对丰度下降，但绝对丰度会大幅增加。沙尘暴能降低人体免疫力，因此致病菌潜在健康风险可能显著增强。通过聚类分析和主成分分析发现，沙尘暴日与非沙尘暴日空气细菌群落差异较大，而沙尘暴前后群落结构差异较小。沙尘暴前后空气细菌群落α-多样性和β多样性均无显著差异，推测沙尘暴只能暂时影响空气细菌群落特征，不能显著改变其群落结构。本研究通过分析了沙尘暴侵袭下北京市空气细菌群落多样性特征及动态，为制定中国北方城市沙尘暴灾害预警措施和建立气传疾病的防控机制提供数据支持。 Abstract:Asian dust events usually transport various pollutants that considerably impact atmospheric processes, biological ecosystems, and human health in downwind areas. To date, the composition and biodiversity dynamics of airborne bacteria have rarely been investigated in urban regions during Asian sandstorms, especially in northern China. Taking Beijing as an example, this study systematically evaluated the effects of sandstorms on the diversity characteristics of airborne bacteria. Air samples were collected from the roof of buildings for nine consecutive days (April 11-19, 2015), covering a sandstorm day (April 15, 2015), as well as four days prior to and after it. After extracting DNA and performing PCR amplifying and 16S rRNA gene high-throughput sequencing, a total of 169,122 high-quality sequences were obtained. Bioinformatics analysis on these mass data showed a high richness of airborne bacteria in this city. Sandstorms could not result in increased OTU numbers, but could result in increased Pielou, Shannon, and Simpson indexes. Bacterial communities in the Beijing atmosphere consisted of 35 phyla. Among them, Proteobacteria, Actinobacteria, Firmicutes, and Bacteroidetes were the dominant phyla, which accounted for 32.76%, 28.09%, 25.46% and 6.32% of the total sequences, respectively; Gemmatimonadetes (2.11%) and Acidobacteria (1.81%) followed; whereas the relative abundance of the other 29 phyla were < 1%. During the sandstorm, the relative abundance of Proteobacteria, Bacteroidetes, Gemmatimonadetes, and Acidobacteria significantly increased from 31.67%, 5.74%, 1.82%, 1.51% to 41.46%, 10.98%, 4.48%, and 4.26%, respectively; whereas Actinobacteria and Firmicutes remarkably decreased from 28.84%, 27.10% to 22.13% and 12.35%, respectively. The genera Psychrobacter, Cellulomonas, Acinetobacter, Pseudomonas, and Clostridium may be opportunistic pathogenic bacteria that potentially threaten human health. During the sandstorm, the relative abundance of these genera decreased, but their absolute abundance increased considerably. Sandstorms potentially weaken human immune capabilities, and hence the potential risks caused by these pathogenic bacteria to human health would increase during sandstorms. Hierarchical cluster and principal component analyses on bacterial communities indicated large differences between the samples from sandstorm and non-sandstorm weather conditions, whereas differences between the samples collected before and after the sandstorm were not obvious. No significant differences were detected in α and β diversity in the comparisons of the air bacterial community collected before and after the sandstorm (t test and Adonis test, P > 0.05). Thus, sandstorms could only temporarily affect the characteristics of airborne bacterial communities, but not permanently change them. Together, this study analyzed the diverse characteristics and dynamics of airborne bacterial communities in Beijing under sandstorm conditions, and the results could provide data support for environmental disaster warnings, as well as the prevention and control of airborne diseases in northern China. 参考文献 相似文献 引证文献

A novel proof of concept for capturing the diversity of endophytic fungi preserved in herbarium specimens.

Herbarium specimens represent important records of morphological and genetic diversity of plants that inform questions relevant to global change, including species distributions, phenology and functional traits. It is increasingly appreciated that plant microbiomes can influence these aspects of plant biology, but little is known regarding the historic distribution of microbes associated with plants collected in the pre-molecular age. If microbiomes can be observed reliably in herbarium specimens, researchers will gain a new lens with which to examine microbial ecology, evolution, species interactions. Here, we describe a method for accessing historical plant microbiomes from preserved herbarium specimens, providing a proof of concept using two plant taxa from the imperiled boreal biome (Andromeda polifolia and Ledum palustre subsp. groenlandicum, Ericaceae). We focus on fungal endophytes, which occur within symptomless plant tissues such as leaves. Through a three-part approach (i.e. culturing, cloning and next-generation amplicon sequencing via the Illumina MiSeq platform, with extensive controls), we examined endophyte communities in dried, pressed leaves that had been processed as regular herbarium specimens and stored at room temperature in a herbarium for four years. We retrieved only one endophyte in culture, but cloning and especially the MiSeq analysis revealed a rich community of foliar endophytes. The phylogenetic distribution and diversity of endophyte assemblages, especially among the Ascomycota, resemble endophyte communities from fresh plants collected in the boreal biome. We could distinguish communities of endophytes in each plant species and differentiate likely endophytes from fungi that could be surface contaminants. Taxa found by cloning were observed in the larger MiSeq dataset, but species richness was greater when subsets of the same tissues were evaluated with the MiSeq approach. Our findings provide a proof of concept for capturing endophyte DNA from herbarium specimens, supporting the importance of herbarium records as roadmaps for understanding the dynamics of plant-associated microbial biodiversity in the Anthropocene.This article is part of the theme issue 'Biological collections for understanding biodiversity in the Anthropocene'.

Robust, real‐time and autonomous monitoring of ecosystems with an open, low‐cost, networked device

Abstract Automated methods of monitoring ecosystems provide a cost‐effective way to track changes in natural system's dynamics across temporal and spatial scales. However, methods of recording and storing data captured from the field still require significant manual effort. Here, we introduce an open source, inexpensive, fully autonomous ecosystem monitoring unit for capturing and remotely transmitting continuous data streams from field sites over long time‐periods. We provide a modular software framework for deploying various sensors, together with implementations to demonstrate proof of concept for continuous audio monitoring and time‐lapse photography. We show how our system can outperform comparable technologies for fractions of the cost, provided a local mobile network link is available. The system is robust to unreliable network signals and has been shown to function in extreme environmental conditions, such as in the tropical rainforests of Sabah, Borneo. We provide full details on how to assemble the hardware, and the open‐source software. Paired with appropriate automated analysis techniques, this system could provide spatially dense, near real‐time, continuous insights into ecosystem and biodiversity dynamics at a low cost.

Rainfall trends and variation in the Maasai Mara ecosystem and their implications for animal population and biodiversity dynamics.

Rainfall exerts a controlling influence on the availability and quality of vegetation and surface water for herbivores in African terrestrial ecosystems. We analyse temporal trends and variation in rainfall in the Maasai Mara ecosystem of East Africa and infer their implications for animal population and biodiversity dynamics. The data originated from 15 rain gauges in the Mara region (1965–2015) and one station in Narok Town (1913–2015), in Kenya’s Narok County. This is the first comprehensive and most detailed analysis of changes in rainfall in the region of its kind. Our results do not support the current predictions of the International Panel of Climate Change (IPCC) of very likely increases of rainfall over parts of Eastern Africa. The dry season rainfall component increased during 1935–2015 but annual rainfall decreased during 1962–2015 in Narok Town. Monthly rainfall was more stable and higher in the Mara than in Narok Town, likely because the Mara lies closer to the high-precipitation areas along the shores of Lake Victoria. Predominantly deterministic and persistent inter-annual cycles and extremely stable seasonal rainfall oscillations characterize rainfall in the Mara and Narok regions. The frequency of severe droughts increased and floods intensified in the Mara but droughts became less frequent and less severe in Narok Town. The timings of extreme droughts and floods coincided with significant periodicity in rainfall oscillations, implicating strong influences of global atmospheric and oceanic circulation patterns on regional rainfall variability. These changing rainfall patterns have implications for animal population dynamics. The increase in dry season rainfall during 1935–2015 possibly counterbalanced the impacts of resource scarcity generated by the declining annual rainfall during 1965–2015 in Narok Town. However, the increasing rainfall extremes in the Mara can be expected to create conditions conducive to outbreaks of infectious animal diseases and reduced vegetation quality for herbivores, particularly when droughts and floods persist over multiple years. The more extreme wet season rainfall may also alter herbivore space use, including migration patterns.

Measuring Biodiversity and Extinction-Present and Past.

How biodiversity is changing in our time represents a major concern for all organismal biologists. Anthropogenic changes to our planet are decreasing species diversity through the negative effects of pollution, habitat destruction, direct extirpation of species, and climate change. But major biotic changes-including those that have both increased and decreased species diversity-have happened before in Earth's history. Biodiversity dynamics in past eras provide important context to understand ecological responses to current environmental change. The work of assessing biodiversity is woven into ecology, environmental science, conservation, paleontology, phylogenetics, evolutionary and developmental biology, and many other disciplines; yet, the absolute foundation of how we measure species diversity depends on taxonomy and systematics. The aspiration of this symposium, and complementary contributed talks, was to promote better understanding of our common goals and encourage future interdisciplinary discussion of biodiversity dynamics. The contributions in this collection of papers bring together a diverse group of speakers to confront several important themes. How can biologists best respond to the urgent need to identify and conserve diversity? How can we better communicate the nature of species across scientific disciplines? Where are the major gaps in knowledge about the diversity of living animal and plant groups, and what are the implications for understanding potential diversity loss? How can we effectively use the fossil record of past diversity and extinction to understand current biodiversity loss?

Morphological specificities of vendace (Salmoniformes: Salmonidae: Coregoninae: Coregonus albula) population in Lake Pleshcheyevo (the Volga River basin): relationships of two phylogenetic lineages in a new zone of secondary contact

This is the report about the secondary contact zone of coregonids in the Upper Volga basin. Two mitochondrial DNA (mtDNA) phylogenetic lineages of vendace Coregonus albula (Linnaeus, 1758) living in Lake Pleshcheyevo have been analyzed and compared in terms of morphological characters. These lineages have developed under the conditions of allopatry and are characterized by strong differences of the mitochondrial DNA sequences. The lineages have coexisted in the same lake since the last glaciation maximum (about 10,000 years ago). The morphological analysis has shown that representatives of both lineages correspond to C. albula, while slight, morphological variations between lineages indicate different food preferences and locomotor abilities. Scenarios where multiple distinct coexisting phylogenetic lineages are characterized by low levels of morpho-ecological divergence are uncommon. These situations are important for understanding biodiversity dynamics and the mechanisms that drive coexistence, adaptive divergence, hybridization, and extinction when genetically divergent lineages meet in secondary contact.