Through the Jungle of Biological Diversity

Biological diversity would apparently seem the most intuitive and easily studied of all the ecological concepts. However, in practice biodiversity has suffered from great number of definitions that vary with the specific needs of the different researchers, thus making it extremely confusing as an ecological concept. In this paper, I shortly review the concept of biodiversity showing that there exists a substantial ambiguity among ecologists as far as biodiversity conceptualization and evaluation is concerned. I conclude that, due to this major disagreement on its very nature, biodiversity may be defined simply as a set of multivariate summary statistics for quantifying different characteristics of community structure.     

乌鲁木齐地区典型灌木群落结构特征及其多样性研究

根据2013年对乌鲁木齐地区典型灌木群落野外50个样地调查的数据,结合双向指示种分析分类方法,从各群落基本特征、物种组成、区系特征、物种多样性等方面对乌鲁木齐地区典型灌木群落结构特征及其多样性进行了分析。结果表明:(1)被调查的50个样地灌木植被群落中共出现了169种植物(其中灌木植物36种,草本植物133种),隶属于118属,31科,其中以藜科、菊科、禾本科等干旱区的表征科居多。灌木物种的植物区系以地中海区、西亚至中亚分布和北温带分布为主。(2)采用TWINSPAN分类方法可将50个样方划分为10个灌木群落类型。乌鲁木齐地区典型灌木群落多样性指数偏低,黑果小檗+宽刺蔷薇+金丝桃叶绣线菊群落的多样性指数最大,群落之间水平差异显著;欧亚圆柏群落、宽刺蔷薇+矮锦鸡儿群落和铃铛刺+喀什菊群落次之;多枝柽柳群落和琵琶柴+喀什霸王群落最低。(3)属于灌丛植被类型的灌木群落,物种多样性指数为草本层灌木层;属于荒漠植被类型的灌木群落,物种多样性空间结构为灌木层草本层。     

福建平潭无居民岛屿空间特征对植物多样性的影响

为了明确岛屿空间特征对植物物种多样性的影响,该研究应用样线法和样方法对福建省平潭主岛周边19座无居民海岛进行植被调查,统计分析每座岛屿的物种丰富度和典型植物群落的Margalef丰富度指数、Shannon-Wiener多样性指数、Simpson多样性指数和Pielou均匀度指数;采用多种函数对种-面积关系进行拟合,并利用冗余分析影响岛屿典型植物群落物种多样性的空间因素,以探究岛屿植物物种多样性的形成与维持机制。结果表明：(1)平潭主岛周边19座无居民岛屿中有12座岛屿以典型的岛屿森林群落为主,有2座岛屿以灌草丛为主且缺乏乔木层,有5座岛屿只有草丛覆盖。(2)19座岛屿的植物物种丰富度均随岛屿面积的增加而增加,当岛屿面积增加到7.184 hm²时,物种数量增加的速率减慢。(3)岛屿的面积、周长、周长面积比、近岸距离是影响物种多样性的主要空间特征,其中岛屿的面积、周长越大,周长面积比、近岸距离越小,岛屿的物种丰富度越高。(4)在岛屿典型植物群落中,乔木层的物种多样性主要受岛屿面积、周长、周长面积比的影响,而灌、草层的物种多样性主要受近岸距离的影响。研究认为,岛屿面积达...     

环境因子对山西太岳山典型森林类型物种多样性及其功能多样性的影响

该研究采用典型样地法,调查群落内物种分布并测量植物功能性状(叶面积和植株高度),对山西太岳山不同坡位华北落叶松-白桦混交林以及辽东栎次生林物种多样性及其功能多样性进行比较分析,探究环境因子对不同群落层次(乔木、灌木、草本)物种多样性及其功能多样性的影响机制,以及环境因子与群落构建之间的联系,为森林生态系统多样性研究以及经营管理提供理论依据。结果显示:(1)华北落叶松-白桦混交林的物种分布更加均匀,物种多样性和功能多样性(乔木层)均显著高于辽东栎次生林。(2)华北落叶松-白桦混交林乔木层功能均匀度与功能分散指数显著高于辽东栎次生林,但灌木草本层低于辽东栎次生林。(3)不同群落层次的物种多样性与功能多样性均呈正相关关系,影响物种分布和性状分布的环境因子存在差异,物种多样性受多种环境因子的综合影响,而单个环境因子对功能多样性影响较大,环境解释力与林分类型和群落层次相关。(4)乔木层物种多样性主要受土壤pH、冠层结构(MLA、林分开度)以及光照影响,灌木层物种多样性与土壤pH和MLA密切相关,林下总辐射、土壤养分(SOC、STN)、土壤相对含水率是影响草本层物种分布的主要环境因子;冠层结构(MLA、林分开度)是影响乔木层功能多样性最主要的环境因子,土壤pH和坡位分别是华北落叶松-白桦混交林和辽东栎次生林灌木层功能多样性的主要影响因子,影响草本层功能多样性的主要环境因子是土壤相对含水率与LAI。研究表明,在垂直分层的森林生态系统中,不同群落层次竞争的主要环境资源存在差异,乔木层通过改变冠层结构和林内环境限制林下物种分布和性状分布。     

Diversity, abundance or rare species as a target for the conservation of mammalian carnivores: a case study in Southern Spain

Management goals in protected areas and/or communities usually include diversity as one of the most valuable and confident criteria. Nevertheless, the use of diversity and related indices as a means of evaluating successful management practices could produce conflicting results. Here we report a case study in one of the most important European protected areas. After 6 years of intensive conservation management of the Don~ana National Park, the general abundance and numbers of the target single-species conservation plan (the Iberian lynx) increased, although carnivore community diversity and evenness decreased. This was a result of a disproportionate increase of an oportunistic native species, the red fox. We propose the combined use of diversity, richness and evenness indices when monitoring management practices such as those reported here.     

Diversity of benthic macrofauna in the eastern English Channel: comparison among and within communities

The diversity of benthic macrofaunal assemblages in the eastern English Channel is described from 707 samples collected with a Rallier-du-Baty dredge during 1971–1975. Four assemblages were primarily defined by means of multivariate data analyses and clustering methods: the Abra alba community, the Ophelia borealis community, the pebbles community and a mixed assemblage of the first three communities. Spatial heterogeneity of these communities is significantly correlated with sedimentary characteristics, although local variability appears to be controlled by both physical and biological processes. Ecological diversity of these communities was analysed considering species richness (S), the Shannon diversity index (H), and rank-frequency diagrammes (RFD). These analyses were performed at two spatial scales: for a single sample, and for a 'site of 10 pooled samples. Thus, several sites were chosen in order to compare diversity patterns and species quantitative structure among and within the communities. The greatest species richness was recorded for the pebbles (57–69) and the A. alba (63–79) communities. In the former, high values may be due to the complexity of microhabitats and the large flux of food related to strong currents. In the latter, both organic matter and terrestrial inputs associated with the mud favour the presence of deposit-feeder organisms. No clear trend was observed among and within the community sites in terms of the species quantitative structure. Thus, convex RFD shapes were observed in three assemblages: the mixed assemblage (offshore site), the A. alba (North Sea), and the pebbles (Normandy coast). Sigmoid shapes were observed in the pebbles (Dover Strait) and A. alba (English coast) communities. Presumably, these shapes can be caused by the combined action of physical (strong currents, substrate stability, mud content in the sediments) and biological factors (co-occurrence of species from different communities, strong species recruitment, relative dominance of carnivorous species).     

Palaeoecological perspectives on pattern and process in plant diversity and distribution adjustments: a comment on recent developments*

Two developments in the understanding of the relationship between sedimentary pollen assemblages, vegetation and plant diversity are discussed. The Prentice model of vegetation–pollen relationships has improved our understanding of how and at what scale sedimentary pollen records vegetation. The modelling framework allows improved palaeoecological study designs that may, potentially, give important new insights into processes of plant migrations in response to climate change. Also, reconstructions of plant communities and landscape openness may be improved. Competing hypotheses for the relationship between vegetation and palynological diversity are discussed and it is concluded that more attention should be focused on evenness aspects of palynological diversity and on hypothesis testing.     

Tree and Liana Enumeration and Diversity on a One-Hectare Plot in Papua New Guinea1

Enumeration of a one hectare plot at 900 m a.s.l in Papua New Guinea revealed 693 individuals of 228 tree and liana species ≥ 10 cm DBH. A 0.1 hectare subplot contained 302 individuals of 106 species 2.5 ≥ DBH < 10 cm. Lauraceae, Moraceae, and Myristicaceae were the most important families in both size classes. This site is very diverse compared with other tropical forests, and like other species-rich sites worldwide, it has high aseasonal rainfall and high rates of natural disturbance.     

东江源头区域鱼类物种多样性及群落组成的特征

生物多样性和鱼类群落结构的变化是反映人类作用及环境变化对鱼类群落影响的重要指标。2010年我们的调查结果显示,覆盖整个东江源头区的12个采样点收集和鉴定的鱼类标本共计7目18科56属74种。除陈氏新银鱼(Neosalanx tangkahkeii)、齐氏罗非鱼(Tilapia zillii)和食蚊鱼(Gambusiaaffinis)3种为外来物种外,其余71种均为土著鱼类。主要以鲤形目(77.5%)、鲇形目(9.9%)和鲈形目(8.4%)为主。优势种为宽鳍鱲(Zacco platypus),占14.87%,其次为马口鱼(Opsariichthys bidens)(9.93%)和侧条光唇鱼(Acrossocheilus parallens)(9.36%)。本研究还以G-F指数、Shannon-Wiener指数、Pielou’s均匀性指数、Margalef丰富度指数和Simpson指数评估了东江源头区域的鱼类多样性;东江源头区域鱼类群落以杂食性、定居性、中下层和底栖种类为主,源头这种鱼类群落组成结构与东江下游鱼类具有相同趋势,但相似性指数仅为0.39。拦河建坝是导致洄游性、半洄游性鱼类减少的主要原因,其次,水体污染、河道取沙、过度捕捞及有害渔具渔法的使用仍是源头区域生物多样性的主要胁迫因素。     

Effects of Tree Genotypic Diversity and Species Diversity on the Arthropod Community Associated with Big‐leaf Mahogany

Despite potential interactive effects of plant species and genotypic diversity (SD and GD, respectively) on consumers, studies have usually examined these effects separately. We evaluated the individual and combined effects of tree SD and mahogany (Swietenia macrophylla) GD on the arthropod community associated with mahogany. We conducted this study within the context of a tree diversity experiment consisting of 74 plots with 64 saplings/plot. We sampled 24 of these plots, classified as monocultures of mahogany or polycultures of four species (including mahogany). Within each plot type, mahogany was represented by either one or four maternal families. We surveyed arthropods on mahogany and estimated total arthropod abundance and species richness, as well as abundance and richness separately for herbivorous and predatory arthropods. Overall tree SD and mahogany GD had positive effects on total arthropod species richness and abundance on mahogany, and also exerted interactive effects on total species richness (but not abundance). Analyses conducted by trophic level group showed contrasting patterns; SD positively influenced herbivore species richness but not abundance, and did not affect either predator richness or abundance. GD influenced predator species richness but not abundance, and did not influence herbivore abundance or richness. There were interactive effects of GD and SD only for predator species richness. These results provide evidence that intra‐ and inter‐specific plant diversity exert interactive controls on associated consumer communities, and that the relative importance of SD and GD may vary among higher trophic levels, presumably due to differences in the underlying mechanisms or consumer traits.     

牦牛放牧率对小嵩草高寒草甸暖季草场植物群落组成和植物多样性的影响

两年的牦牛放牧试验结果表明:在暖季草场,随着放牧率的提高,禾草和莎草类功能群的盖度、生物量及其组成与高度减小,它们与放牧率呈显著的负相关 P<0.05 可食杂草和毒杂草类功能群的盖度、生物量及其组成与高度增加,它们与放牧率呈显著的正相关 P<0.05 各功能群的盖度与生物量之间是显著的正相关关系 P<0.05 .对照草地由于没有牦牛的采食,群落由少数优势种植物所统治,群落结构趋于简单,物种组成贫乏,物种多样性和均匀度指数最小;轻度放牧牦牛选择采食对植物群落的影响较小,群落的物种丰富度指数、均匀度指数和多样性指数均不高;中度放牧提高了资源的利用效率,增加了群落结构的复杂性,草地的物种丰富度指数、均匀度指数和多样性指数均最高,该结果支持 中度干扰理论 ;重度放牧由于牦牛采食过于频繁,改变了植物的竞争能力,导致植物种的均匀度下降,多样性减少.不同放牧率草地群落的物种数 S 、丰富度指数 Ma 、多样性指数 Shan-non-Wiener指数H′和Simpson指数D 、均匀度指数 Pielow指数J′ 的排序为:对照<轻度放牧<重度放牧<中度放牧,优势度指数 Berger-Parke指数 的变化趋势则与之相反.     

干扰对云顶山亚高山草甸群落物种多样性的影响

放牧等干扰会对亚高山草甸群落的外貌、结构及功能造成影响。为了揭示在外界干扰下云顶山草甸群落的变化规律,对云顶山草甸进行群落学调查,共取45个样方（1×1 m）。在此基础上,应用TWINSPAN对草甸群落进行数量分类;运用丰富度指数、物种多样性指数和均匀度指数分析了不同程度干扰对草甸植物物种多样性的影响及其变化规律。结果表明：该草甸划分为6个群丛,受干扰程度中等的群丛3的丰富度、多样性以及均匀度都最高,受干扰程度轻的群丛1次之,而受干扰程度较重的群丛6最低。同时干扰对该草甸不同植物功能群及不同物种的影响趋势是不一致的。随着干扰程度加重,灌木和豆科等植物在群落中的优势地位逐渐减弱,甚至消失;禾草中的部分种如披针叶苔草（Carex lanceolata）等对干扰响应不明显;毒草和一些杂草种类在群丛中的优势地位明显上升。     

多样性指数公式在鸟类群落中应用的探讨

一、前言多样性是反映生物群落功能的组织特征,它与生境密切相关,可以作为生态学上的一个灵敏度指标;它是群落中关于丰富度和均匀度的一个函数,用其指数可以定量地分析群落的     

黄土丘陵沟壑区不同植被恢复类型昆虫群落结构及多样性的研究

为探讨黄土高原植被恢复过程中植物与昆虫群落的关系,评价人工植被和自然恢复植被种类搭配的合理性,为退化生态系统的植被恢复提供依据。采用样地调查法,在黄土丘陵沟壑区纸坊沟流域研究比较了不同植被恢复类型昆虫群落组成、结构及多样性的变化。结果表明,2种不同植被恢复类型区昆虫有189种(含蜱螨目),分别隶属13目84科。而不同植被恢复类型昆虫群落的物种数、丰富度、多样性、均匀度及优势度指数值均有明显差异。以20a自然封育植被恢复区昆虫群落的物种数、丰富度、多样性、均匀度指数值均较高,其值分别为160、21.17、1.4914和0.6918。优势度则以人工治理区(0.7251)>自然封育区(0.5845)。说明从人工治理区到自然封育区,随着植被种类增加,昆虫种类相应增加,优势种由突出降至不明显,昆虫群落稳定性提高。     

阿拉善雅布赖风沙区荒漠植物群落结构和物种多样性研究

根据阿拉善雅布赖风沙区30个样地的调查资料,对该区荒漠植物群落物种多样性进行分析.结果表明:雅布赖风沙区天然植被物种组成简单,以旱生、盐生或超旱生的小灌木和多年生草本植物占主导地位,体现出荒漠半荒漠和草原化荒漠植物群落的特点.群落优势层片为灌木层,其物种组成以矮化的半灌木和小灌木为主(占41%～90%),受环境变化的影响较小,结构比较稳定;草本层片组成中以多年生草本为主,但一年生草本的数量却占到81.5%～98.8%,为不稳定层片.雅布赖风沙区荒漠植物群落多样性数量特征值差异较大,在植被生态建设时应关注不同生活型植被的防护效应与当地大风和沙尘暴在发生时间上的匹配性,针对半灌木、小灌木和多年生草本覆盖特有的防风性能,重视灌木和多年生草本的恢复与建设,以取得抵抗风沙、稳定当地生态环境的效果.     

Effects Of Vegetation and Soil on Species Diversity of Soil Dwelling Diptera in a Heathland Ecosystem

The role of vegetation and soil factors on the biodiversity of two soil dwelling, saprophagous, fly families (Sphaeroceridae and Lonchopteridae) in a heathland ecosystem were investigated. The fly community is primarily affected by soil humidity and the amount of organic matter while the vegetation structure and species composition only indirectly influence the fly communities. There was no correlation between plant species richness and the fly diversity indices. Based on our results and literature data, we hypothesise that the direct effects of the vegetation is more evident for herbivorous insects than for species that do not feed on plants. The investigated families show a clear response to microhabitat differences in the soil factors, which makes them promising indicators for soil health and as tool for monitoring environmental changes.     

吉林中、西部平原区土壤弹尾虫群落结构的比较

2003年7月和9月对吉林省中、西部平原区天然次生林、农田、居民点园地、防护林和天然割草场等典型生境进行了土壤弹尾虫的调查,用Tullgren法提取弹尾虫,应用个体密度、类群数量、群落多样性、丰富度和均匀度等指数,研究土壤弹尾虫群落结构特征,了解土地利用差异对土壤弹尾虫群落结构的影响。共捕获土壤弹尾虫2亚目8科12属5 531头,优势类群为Onychiurus、Folsomia、Acanthocyrtus、Xenylla和Coloburella属, 占总捕获个体数的90.3%。弹尾虫类群空间分布的广狭与个体数量的多寡在吉林省中、西部平原区呈现出明显的一致性;中部平原区与西部平原区土壤弹尾虫群落组成差异主要体现在优势类群个体密度方面;生境类型明显影响弹尾虫个体密度分布,其中农田、居民点园地和防护林土壤弹尾虫个体密度较低,在不同土层间分布比较均匀,但生境差异对弹尾虫类群数的影响不明显;同时农业生产活动也降低了弹尾虫群落多样性。     

Genetic Diversity Assessment of Spanish and Some Endangered Tunisian Pea (Pisum sativum L.) Accessions Based on Microsatellite Markers (SSRs)

In the current investigation, 28 accessions of Spanish and Tunisian peas were characterized by eight SSR polymorphic markers to assess their genetic diversity. Many methods have been applied to evaluate these relationships including diversity indices, analysis of molecular variance, cluster analysis, and population structure. The means of diversity indices, the polymorphism information content (PIC), the allelic richness, and the Shannon information index were 0.51, 3.87, and 0.9, respectively. These results revealed a large polymorphism (84.15 %) which produced a higher degree of genetic distance amongst the accessions. The unweighted pair group approach with arithmetic mean divided the collection of these accessions into three major genetic clusters. Therefore, this article has clearly demonstrated the usefulness of the SSR markers that can significantly contribute to the management and conservation of pea germplasm in these countries, as well as to future reproduction.     

山西南部脱皮榆群落生态特征及其物种多样性的研究

选择脱皮榆群落分布较为集中的霍山、中条山等2个地段,设计7个样地,用样方法进行调查,共做样方585个。分析了脱皮榆群落的种类组成、区系特点、群落外貌、垂直结构等群落学特征,并对该群落的环境概况进行分析,计测了不同地段群落的重要值指标和不同层次上的Shannon-Wiener指数、Simpson指数和Pielou指数。结果表明,脱皮榆主要分布于海拔1100-1650m的中海拔山地。群落组成种类约156种,北温带分布属占优势,显示了脱皮榆群落具有北温带性质。高位芽和一年生植物种类多,显示了脱皮榆群落分布区域夏季水热条件良好,冬季漫长、寒冷、干旱的气候特点。乔木层平均高度约13m,多样性指数H为1．0260一1,5907;灌木层H值0．9983—2．4478;草本层H值为0．9047—3.0621。研究为脱皮榆可持续利用和保护提供了有益的参考。     

林分密度对桉树人工林群落结构和物种多样性的影响

采用典型样地法,以四川新津县普兴镇桉树(Eucalyptus robusta)人工林为研究对象,设置5种不同林分密度(A.625株·hm~(-2);B.750株·hm~(-2);C.875株·hm~(-2);D.1 000株·hm~(-2);E.1 125株·hm~(-2))样地各3个,对不同林分密度人工林群落结构和物种多样进行分析,探讨确定桉树人工林的合理栽植密度,为维持桉树人工林群落结构稳定、增加物种多样性提供依据。结果表明:(1)研究区桉树人工林群落共记录到96种植物,隶属于51科79属;在各个林分密度的群落中,植物科属种数量变化规律均为:草本层灌木层乔木层;当密度为1 000株·hm~(-2)时,乔木层物种数最高(6种);当密度为750、875株·hm~(-2)时,灌木层群落物种数最高(17种);在林分密度625株·hm~(-2)下,草本层物种数最高(32种)。(2)桉树人工林群落各层次的丰富度指数D值、Shannnon-Wiener指数H值、Simpson指数H′、Pielou均匀度指数Jsw)值均表现为:草本层灌木层乔木层;乔木层的D值和H′值在875株·hm~(-2)密度下最大,H值在625株·hm~(-2)密度下最大,Jsw)值在750株·hm~(-2)密度下最大;灌、草层各指数分别均在密度750、625株·hm~(-2)时有最大值。(3)从群落结构上看,5种林分密度的群落径级结构均呈单峰型分布,乔木个体多分布在中径级(7.0≤d23.0cm);高度级结构与径级结构对林分密度的响应不一致,密度A、B、C和D、E的个体分别集中在高度级Ⅱ~Ⅴ(6.0≤h18.0m)、Ⅲ~Ⅴ(9.0≤h18.0m)、Ⅱ~Ⅲ(6.0≤h12.0m)和Ⅳ~Ⅴ(12.0≤h18.0 m)。(4)各层次优势种不同,乔木层中桉树是绝对优势树种,各密度林分中构树(Broussonetia papyrifera)的重要值基本仅次于桉树;灌木层中,桉树幼苗只在密度E出现,构树在各密度下优势地位显著,在密度B~D中,均有八角枫(Alangium chinense)和女贞(Ligustrum lucidum)存在,并在密度B下八角枫(0.118 4)和女贞(0.183 2)长势较好,具有较大的更新潜力;青蒿(Artemisia carvifolia)和荩草(Arthraxon hispidus)作为草本层的优势种在5种林分密度下都有生长。研究认为,林分密度750株·hm~(-2)(密度B)是新津桉树人工林的最适林分密度,该密度更有利于该地区桉树人工林群落结构和物种多样性的稳定可持续发展。