深圳福田红树林的群落学研究：Ⅱ.多样性与种群格局

本文以Ｓｉｍｐｓｏｎ指数、Ｓｈａｎｎｏｎ一Ｗｉｅｎｅｒ指数、种间相遇率（ＰＩＥ）和均匀度公式研究了深圳福田红树林群落的物种多样性,结果为：Ｓｉｍｐｅｎ指数为１．４０,Ｓｈａｎｎｏｎ一Ｗｉｅｎｅｒ指教为０．７８,ＰＩＥ为０．２８,均匀度为１８．９８％。生态优势度为０．５６．与南亚热带常绿阔叶林群落相比,红树林群落的多样性指数和均匀度明显偏低,生态优势度则偏高。利用方差／均值法测定了种群分布格局,结果表明,３个种均趋于集群分布。     

深圳南山区天然森林群落多样性及演替现状

对南山区5个主要天然森林群落(铁榄群落、鼠刺 降真香群落、鸭脚木群落、假苹婆群落、水翁 假苹婆群落)的组成结构及物种多样性进行分析,并与相邻的香港地区地带性森林群落(黄桐群落)作比较。结果表明,依照亚热带及南亚热带森林群落演替规律,南山区天然林处于不同的演替发育阶段：铁榄群落处于演替第3阶段;鼠刺 降真香群落处于第4阶段;其它3个群落处于第5阶段,均未达到稳定的顶极群落阶段。随着铁榄群落、鼠刺 降真香群落、鸭脚木群落、假苹婆群落、水翁 假苹婆群落这个演替序列,物种丰富度的变化规律是：先逐渐上升,到达一个峰值,再缓慢下降。Shannon-Wiener指数和Pielous均匀度指数的变化规律与物种丰富度相同,Simpson指数变化曲线与这些指数相反。但这些指数反映的结果是一致的。综合多个指数分析,鸭脚木群落物种多样性最大,即当群落中阳生性树种与中生性树种优势度相差不大时。群落具有最大的物种多样性。多样性比较结果显示,南山森林群落物种多样性大大低于香港黄桐群落。5个群落的Shannon—Wiener指数在2．04～2．953之间,明显低于黄桐群落,其Shannon—Wiener指数为4．74;Simpson指数0．1～0．268,黄桐群落为0．05;Pielous均匀度指数64．2％～74％,黄桐群落为79％。南山森林群落物种多样性水平低下的状况与长期的人类干扰有关,必须尽快采取“封山育林”等相应措施来促进群落的保护和恢复。     

管涔山撂荒地植物群落演替过程中物种多样性研究

用TWINSPAN分类方法将管涔山撂荒地植物群落的演替过程划分为7群丛,分别属于植被演替的3个阶段--草本群落阶段、灌丛群落阶段和森林群落阶段.用物种多样性指数分析了物种丰富度、均匀度、多样性和优势度的变化规律,结果表明,随着演替时间的延长,物种丰富度和多样性有增加的趋势,优势度、均匀度有降低的趋势.用DCA排序分析植物群落的结构、组成和生活型在演替过程中的变化规律,表明随着群落环境条件的改善,群落内物种的组成发生了很明显的变化,最后发展为适应该区域环境条件的、以华北落叶松为建群种的、稳定的群落,结果显示群落内物种组成愈丰富,则多样性愈大.进一步用DCA排序分析物种多样性与海拔和时间之间的关系,表明随着海拔的升高和时间的延长,结论和前面一致--物种丰富度和多样性逐渐增加,优势度、均匀度逐渐降低.     

杭州湾滩涂湿地植被群落演替与物种多样性动态

以杭州湾不同年份形成的滩涂湿地植被群落为研究对象,采用样线法结合样方法进行调查取样,并通过除趋势对应分析排序研究了群落演替的动态和方向,同时采用Pielou均匀度指数、Margalef丰富度指数、Shannon-Wiener多样性指数和Simpson多样性指数分析了物种多样性在群落演替过程中的动态变化.结果表明:该区域植被群落演替序列为海三棱藨草群落→芦苇群落→柽柳 芦苇群落→旱柳 白茅群落;随着演替的进行,群落物种丰富度显著增加,均匀度逐渐降低,物种多样性呈先增加后降低的趋势.     

海南岛清澜港红树林群落演替系列的物种多样性特征

应用物种丰富度、Ｓｉｍｐｓｏｎ指数、Ｓｈａｎｎｏｎ－Ｗｉｅｎｅｒ指数、Ｐｉｅ种间相遇机率、ＭｃＩｎｔｏｓｈ指数和基于Ｓｉｍｐｓｏｎ的均匀度指数测度海南省清澜港红树林演替过程中群落物种多样性动态特征。结果表明。除均匀度指数变化规律不明显外,其它均表现出非常一致的动态趋势,即群落在演替初始阶段变化趋势均是由少增多,在中期阶段达到高峰后趋于下降,但在演替的后期阶段又有回升趋势。     

秦岭太白山弃耕地植物群落演替的生态学研究

应用物种丰富度、Ｓｉｍｐｓｏｎ指数、Ｓｈａｎｎｏｎ－Ｗｉｅｎｅｒ指数、Ｐｉｅｌｏｕ均匀度指数、Ａｌａｔａｌｏ均匀度指数研究了太白山弃耕地植物群落次生演替过程中的群落α多样性动态特征,结果表明,群落在由一年生草本植物群落阶段向多年生草本植物群落、灌丛、混交林阶段的演替过程中,群落多样性指数逐渐上升,至混交林阶段达到最高值。若以分布在这一垂直地带的代表性森林群落锐齿栎林为演替进一步发展的方向,则由多样     

湘西北蜡梅群落典型样地的物种多样性特征初探

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

新疆喀纳斯湖北端河漫滩湿地植物群落演替

对喀纳斯湖北端河漫滩湿地植物群落进行了调查取样,通过除趋势对应分析(detrended correspondence analysis,DCA)排序研究了群落演替的动态,同时采用Shannon多样性指数、Margalef丰富度指数、Simpson多样性指数和Pielou均匀度指数,分析了物种多样性在群落演替过程中的动态变化,并运用去势典范对应分析(detrended canonical correspondence analysis,DCCA)方法,分析了不同样方中土壤因子与群落多样性指数之间的关系。结果表明:1)该区域植物群落演替序列为泽生苔草群落→西伯利亚早熟禾群落→金露梅群落→沼桦群落→西伯利亚云杉群落;2)随着演替的进行,群落物种优势度显著增加,而物种多样性呈先增加后降低的趋势,金露梅群落最高;3)土壤含水量和群落物种优势度之间存在显著负相关。     

关帝山次生林区典型森林交错带物种多样性研究

森林交错带富于高的生物多样性。应用Shannon-Weiner指数、Simpson指数、Margalef指数、Pielou指数,研究了关帝山次生林区森林交错带中处于不同演替阶段的群落物种多样性动态特征,同时对交错带内群落与相邻群落的物种多样性特怔进行了对比分析。结果表明：处于森林演替不同阶段的交错带,在由阔叶林、针阔叶混交林到针叶林的演替过程中,Shannon－Weiner多样性指数、Margalef丰富度指数均表现出单峰变化趋势,在演替中后期的针阔叶混交林阶段,指数值最高。Simpson优势度指数则表现出凹形变化．不同于多样性、丰富度指数,在演替中后期,达到最低值。Pielou均匀度指数表现出下降趋势。交错带内群落与相邻群落相比,Shannon－Weiner多样性指数较高,具有高的物种多样性,边际效应表现为正效应。Margalef丰富度指数变化与Shannon－Weiner多样性指数变化不一致,只在一定程度上证明了边际正效应的影响。两指数共同反映出研究地区的森林交错带内群落具有较高的物种多样性。     

海岛矿区岩质边坡植物群落演替中物种多样性的变化

通过植物群落调查,采用Shannon多样性指数、Simpson优势度指数、Margalef丰富度指数和Pielou均匀度指数,结合DCA排序和一元线性回归分析,考察了舟山海岛矿区岩质边坡植物物种构成特征,研究了植物群落演替过程中生物多样性的变化。结果表明:研究区可划分为3个植物群落演替阶段(草本植物群落阶段、灌丛群落阶段和灌乔群落阶段);演替过程中,物种丰富度指数显著上升,多样性指数和优势度指数逐渐升高;具有矿区特殊生境适应性的植物配置在边坡植被恢复进程中与自然植被表现出一定的差异,演替过程依次为迁入物种生长期、迁入物种与人工导入种竞争期、迁入物种与人工导入种稳定共存期;人工导入群落演替后期的植物种大大加速了群落演替进程;合理的植物配置更能促进群落向正演替方向发展。     

Species concept and speciation

Defining and recognizing a species has been a controversial issue for a long time. To determine the variation and the limitation between species, many concepts have been proposed. When a taxonomist study a particular taxa, he/she must adopted a species concept and provide a species limitation to define this taxa. In this paper some of species concepts are discussed starting from the typological species concepts to the phylogenetic concept. Positive and negative aspects of these concepts are represented in addition to their application.     

Patterns of bryophyte diversity and rarity at a regional scale

Information on bryophyte diversity and rarity were combined withinformation on soil conditions and land use for Walloon Brabant (centralBelgium, 1091 km²) in order to investigate whichlandscape features sustain the most rare and diverse species assemblages.Presence–absence of 325 bryophyte species was recorded in 87 grid-squaresof 4 × 4 km. Species diversity was significantly correlatedwith forest cover (r = 0.71, P <0.001), sandy soils (r = 0.61, P <0.001), loamy soils, (r = –0.68,P < 0.001), and agricultural fields(r = –0.49, P < 0.001). Themost diverse grid-squares possessed up to 182 species and were characterized byat least 10% forest cover and the presence of unique micro-habitats.Grid-squares with forest cover reaching at least 10% but lacking uniquemicro-habitats contained between 90 and 130 species. Below 10% forest cover,diversity ranged between 55 and 110 species per grid-square. However, even theleast diverse cultivated areas included a significant amount of the regionallyrare species. A number of the latter are characteristic in other areas forspecific primary habitats lacking in Walloon Brabant but display an unexpectedability to disperse throughout hostile areas and colonize secondary habitats.The tendency of such species to occur in man-made habitats decreased our abilityto predict species richness and rarity from landscape features and soilconditions.     

Diversity and abundance of leafhopper species (Homoptera: Cicadellidae) among red maple clones

A survey was conducted in the 2001 growing season to examine the leafhopper diversity and abundance among trees of 17 red maple (Acer rubrum) clones. Yellow sticky traps were used to qualify and quantify the number of aerial leafhoppers from 1 May 2001 until 4 September 2001. A total of 45 species from eight different leafhopper subfamilies, for a total of 6055 individuals, were considered in this study. The mean number of leafhoppers collected, mean species richness, diversity and evenness were significantly lower on traps of trees for October Glory than for the other clones. Yet, none of the leafhopper species dominated the weekly samples. Species similarity among clones ranged from 56 to 90%. No two clones had complete similarity. Franksred and trees of a controlled cross between October Glory × Autumn Flame shared the highest degree of species similarity, while clones from PA, USA and RI, USA were the least similar. The development of new clones did not create new pest problems, but suppressed populations of damaging pests, and maintained the diversity of low abundance species.     

Species richness, diversity and biomass production of desert annuals in an ungrazed Rhanterium epapposum community over three growth seasons in Kuwait

Two blocks, each consisting of twelve 0.25 m²permanent plots, were established in a community dominated by desert annuals inan area of Kuwait protected from grazing, and community attributes wereinvestigated over three growth seasons. A linear relationship was found betweenestimated desert annual cover and biomass production. Species frequency wasassessed by the number of 100 cm² subplots occupied byaspecies in a block (block incidence). Over the three seasons,vegetation features varied considerably. The first season (spring 1997) wascharacterised by very sparse vegetation cover, low vegetation block incidence(sum of individual block incidences of each species present in a block) and lowspecies richness. The second season (spring 1998) had high vegetation cover,relatively low vegetation block incidence, but high species richness. In thethird season (spring 2000), vegetation cover was very sparse (as in 1997), butboth blocks had the highest vegetation block incidence of the three years andspecies richness was moderately high, although individual plants were verysmall. The growth period was much shorter in the very productive andspecies-rich 1998 season than in 2000. Fluctuations in biomass and speciesincidence coincided with pronounced variation in key meteorological variables,in particular the onset of the first rains, the amount of rainfall during thegrowing season and its temporal distribution. Species composition, however,appears mainly to be determined by the amount and possibly the timing of thefirst rainfalls of the season to trigger germination. There was little evidenceto suggest that particularly favourable or unfavourable microsites existed inplots for more than one vegetation period, either for individual species or fordiversity in general. Despite substantial between-season fluctuations inincidence, the relative abundances of the more frequent species to each otherremained broadly similar over the three seasons, with Plantagoboissieri being the predominant species and accounting for thelargest proportion of biomass.     

论物种的客观真实性

关于物种的概念和本质的争论由来已久。大多数学者认为种是自然界客观存在的真实单位,是形态上和生殖上间断的群体体系,与种内连续的群体体系——宗,有着本质的区别。少数学者则认为种是主观意识的产物,是为了分类的目的而任意确定的人为的分类阶元,与宗只有程度的不同而无本质的区别;只有个体才是客观真实的单位。以形态标准为主的分类学种概念和以生殖隔离为标准的生物学种概念只能说代表了自然界有机体类群不连续性的两个不尽相符,但部分一致的侧面,而不能说就是客观物种的反映。自然界的生命有机体有两重性。它们既不是一群乱七八糟的乌合之众,也不是秩然不紊的鳞次栉比,而是以群体的组织形式适应于各自分布区内的生态位,在表型和基因型的变异式样上具有一定规律的遗传多样性。物种的客观本质也有两重性。物种作为有机体组合的单位既存在又不存在。说物种客观存在是因为按形态或生殖的不连续性标准划分的“种”在自然界具有一定的普遍性;说物种并非客观存在是因为至今还没有一个能把所有的生命有机体都划分成统一的生物学单位的不连续性标准。     

The species-area relation III. A third model for a delimited community

Summary A mathematical model of the species-area relation is described for a group of limited species. This model is a modification of that proposed earlier (Kobayashi, 1975), being assumed that the limited species are expected to occur in a habitat under consideration. The model equation gives a sigmoid species-log area curve implying that few rare species are found in a group of species. The good agreement between observation and this model is exemplified with the data of plant and arthropod communities. The implication of parameters involved are examined in connection with those of the preceding model, and the underlying ecology of the model is discussed. Contribution from the Laboratory of Applied Zoology, Yamagata University, No. 83.     

The species in primatology

Biologists of the late eighteenth and early nineteenth centuries all bandied about the term “species,” but very rarely actually said what they meant by it. Often, however, one can get inside their thinking by piecing together some of their remarks. One of the most nearly explicit‐appropriately, for the man who wrote a book called The Origin of Species – was Charles Darwin 1 : “Practically, when a naturalist can unite two forms together by others having intermediate characters, he treats the one as a variety of the other… He later translated this into evolutionary terms: “Hereafter, we shall be compelled to acknowledge that the only distinction between species and well‐marked varieties is, that the latter are known, or believed, to be connected at the present day by intermediate gradations, whereas species were formerly thus connected”^1:484‐5     

Changes in plant species diversity along a chronosequence of vegetation restoration in the humid evergreen broad-leaved forest in the Rainy Zone of West China

Plant species diversity has been recognized as one of the vital attributes for assessing vegetation restoration. Changes in the diversity may be related to different stages of succession. In this study, 54 sites of humid, evergreen, broad-leaved forest were selected in the Rainy Zone of West China. A chronosequence of the sites was used to study the successive patterns of the diversity in the forest that had undergone natural regeneration for 5 to 350 years and to test the hypothesis that the diversity is maximized in mid-succession. Data were collected simultaneously at different stages of succession, and four α-diversity indices (species richness, Margalef index, Shannon-Wiener index, Pielou Evenness index) and two β-diversity indices (Whittaker index, Sørensen’s index) were calculated for each stratum in each plot. A total of 394 vascular plant species were recorded. From the β-diversity indices, the forest succession may be divided into the early-successional stage (before 50 years), mid-successional stage (from 50 to 300 years), and late-successional stage (after 300 years). In this community, the species diversity and richness were found to be the greatest at the mid-successional stage, followed by the late- and early-successional stages. The results of regression analysis indicated that the richness and Margalef index peaked around the 175th and 165th year, respectively. Shannon-Wiener index values also appeared to follow an approximately humped pattern of succession and were maximal around the 100th year. However, the species evenness did not show any significant relationship with successional age. Our results demonstrate (1) forest restoration is a long-term process and the formation of climax forest requires at least 300 years and (2) the forest has a strong capacity for restoration. Our results also suggest Lindera limprichitii and Machilus pingii as ideal tree species for afforestation because of their wide niche.     

Microhabitat variations and seed bank-vegetation relationships in a desert wadi ecosystem

Due to extreme variability in patterns of rainfall, plant seed banks are an important component of desert habitats. Here I report on effects of standing vegetation and three different microhabitats (channel, bank and terrace) on the soil seed bank of a desert wadi ecosystem in the Eastern Desert of Egypt. A total of 450 soil samples at 45 stands were collected to represent the different wadi microhabitats. The germinable seed bank was estimated by controlled counts of seedling emergence. The floristic composition, functional properties and diversity of the soil seed bank, as well as its similarity with the standing vegetation varied among wadi microhabitats. Such variation could be attributed to differences in disturbance intensity among microhabitats (terrace < bank < channel) and variation of soil factors along the microtopographic gradient. Channel showed the highest species richness and size of soil seed bank, followed by bank and then terrace. Moreover the Shannon index of diversity of the seed bank and its similarity with standing vegetation were significantly greater in both channel and bank microhabitats than in terrace. At the level of plant functional groups, number of seeds of annuals was higher in both channel and bank than in terrace. Shrubs were more abundant in seed banks of channel compared to terrace. The size and species richness of seed bank were increased with the total plant cover, annual/perennial ratio and species richness of the standing vegetation.     

Environmental drivers of the bryophyte propagule bank and its comparison with forest-floor assemblage in Central European temperate mixed forests

Species richness, composition and abundance of the bryophyte diaspore bank of Central European temperate mixed forests were compared with the forest-floor bryophyte assemblage. The impact of environmental variables and anthropogenic disturbances, including tree species composition, stand structure, microclimate, light conditions, soil and litter properties, management history, and landscape properties, potentially influencing bryophyte diaspore bank assemblages were explored. Thirty-four, 70–100 years old mixed stands with differing tree species composition were examined in the ?rség National Park, Western Hungary. The diaspore bank was studied by soil collection and cultivation, and data were analysed by multivariate methods. Contrary to the forest-floor bryophyte assemblage, where substrate availability, tree species composition and stand structure were the most influential environmental variables, the composition and abundance of the diaspore bank was mainly affected by site conditions (microclimate, litter and soil properties). Species richness of the bryophyte diaspore bank was lower than that of the forest-floor bryophyte assemblage. Short-lived mosses (colonists, short-lived shuttles) were dominant in the diaspore bank, as opposed to the forest-floor bryophyte community, where perennial mosses dominated. In the studied forests, the importance of the bryophyte diaspore bank was relatively low in the regeneration and maintenance of the forest-floor bryophyte vegetation.