江西武夷山河岸带阔叶林群落的物种组成和多样性分析

以江西武夷山国家级自然保护区河岸带阔叶林群落为研究对象,对其物种组成进行调查,并采用物种丰富度指数、多样性指数和均匀度指数分析物种多样性。结果表明,保护区河岸带物种极丰富,三条水系10个样方中共调查到维管束植物93科174属304种,群落建群种和灌木层优势种均以常绿阔叶树种为主,物种组成具有典型的亚热带植被特色,以壳斗科、樟科、山茶科物种最多。保护区不同海拔河岸带物种丰富度指数、多样性指数的变化规律基本一致。     

Body size and resource partitioning in ladybirds

[First paragraph]Resource utilisation is usually viewed in terms of food species size (Schoener, 1974) with each species in a predator guild adapted to exploit a particular-sized species of prey. Large species of predators exploit large species of prey and vice versa. That is, each species in a guild is able to displace other species from a particular portion of the resource space by virtue of it being better adapted to exploit that particular species of prey in that resource space.     

The effect of developmental variation on hybridization and rarity in Stipoid grasses

Developmental variation in some Achnatherum species was evaluated for two kinds of groups, (1) species pairs that do or do not hybridize and (2) rare and common species. Variation was assessed in two different ways, one that captures developmental events expressed in an individual and one reflecting developmental events that are part of the information systems of a species. The former captures the effect of the environment on development; the latter expresses developmental variation without the information controlling ontogenetic events being filtered through the environment. Development variation is lower for species pair that hybridizes when the effect of development in an individual is expressed. When that variation is of the species information system, the non-hybridizing species pair shows a lower level of developmental variation, likely the effect of greater similarity between those species. It is lower for rare species when variation in development is that of the information system of a species. The lower level of developmental variation seen in species pairs that hybridize likely reflects the necessity of compatible developmental programs in order for a hybrid to appear. Lower variation in development in rare species is expected. Here, though, the lower variation is a property of the species and not of the environment.     

The effects of protection from fishing on species richness: distinguishing between alternative explanations

Marine reserves that prohibit fishing often result in greater densities of individuals and more species than adjacent fished areas. However, simple conclusions about their effects on species richness are confounded, because more species are expected to occur wherever there are more individuals. Here, there is an important distinction between the number of species per sampling unit (species density), and species richness measured as the number of species per given number of individuals. When conservation of species richness is an important goal, analyses need to discriminate between the alternative explanations for differences in the number of species. We used rarefaction to test whether species richness was higher in two ‘no-take’ marine reserves after controlling for differences in the density of individuals. We surveyed each reserve in three different years. There was a higher density of individuals and species in each reserve than in adjacent fished areas. However, rarefaction analyses indicated that effects on species richness were weak after controlling for the number of individuals: slightly higher species richness was recorded inside each reserve in one of three surveys, but the difference was small, and was apparent only when the maximum number of individuals was approached. Our results therefore indicate that patterns in species density were not reflected by patterns in species richness—the application of rarefaction methods is needed to determine the responses of species richness to protection elsewhere. The distinction between species density and species richness will not be important in all situations, but when it is important, inferences about species richness cannot be reliably deduced from measurements of species density.     

上升流和水团对浙江中部近海浮游动物生态类群分布的影响

依据2010年4月、7月和11月对浙江中部近海上升流海域进行的海洋调查资料,运用定量、定性方法,探讨了上升流对该海域浮游动物生态类群分布的影响.结果表明:3个季节共鉴定浮游动物64种,桡足类占主要优势,包括5个生态类群,分别是暖温带近海种、暖温带外海种、亚热带近海种、亚热带外海种和热带大洋种.在种类数组成上,春季以暖温带近海种为主,夏季则是亚热带近海种和亚热带外海种居多,秋季也是亚热带种居多,其中夏季暖温带种种类数要高于春季和秋季,这一现象与同时期东黄海沿海有所不同,主要是由于上升流将一些在海洋底部度夏的暖温种带至海洋表面造成的.此外,3个季节生态类群都是以近海种为主,表明沿岸流是影响这一海域的最主要的水团.在丰度组成上,4月暖温带近海种占总丰度的98.79％,7月暖温带近海种也是组成丰度的重要部分,10月则是亚热带近海种丰度最高.丰度组成所反映的规律与种类数组成规律一致.上升流的存在导致夏季近海暖温带种大量出现,是影响这一海域浮游动物生态类群组成的重要因素;受长江径流和椒江径流的影响,近海种成为主要生态类群,是这一海域浮游动物的一个重要的生态特征.     

Exploring taxonomic filtering in urban environments

Question: Several mechanisms have been proposed that control the spatio‐temporal pattern of species coexistence. Among others, the species pool hypothesis states that the large‐scale species pool is an important factor in controlling small‐scale species richness through filtering of species that can persist within a species assemblage on the basis of their tolerance of the abiotic environment. Because of the process of environmental filtering, co‐occurring species that experience similar environmental conditions are likely to be more taxonomically similar than ecologically distant species. This is because, due to the conservatism of many species traits during evolutionary diversification, the ability of species to colonize the same ecological space is thought to depend at least partially on their taxonomic similarity. The question for this study is: Under the assumption of trait conservatism, does environmental filtering lead to nonrandom species assemblages with respect to their taxonomic structure? Methods: The significance of taxonomic filtering in regulating species coexistence is tested using data from 15 local species assemblages from the urban flora of Rome (Italy). To find out whether the taxonomic structure of the selected’ local’ species assemblages was significantly different from random, we used a Monte Carlo simulation in which for each local species assemblage, the actual taxonomic diversity was compared to the taxonomic diversity of 1000 virtual species lists of the same size extracted at random from a larger ‘regional’ species pool. Results: We found that in most cases the local species assemblages have a higher degree of taxonomic similarity than would be expected by chance showing a phenomenon of ‘species condensation’ in a small number of higher‐level taxa. Conclusions: Our observations support the species pool hypothesis and imply that environmental filtering is an important mechanism in shaping the taxonomic structure of species assemblages. Therefore, the incorporation of taxonomic diversity into landscape and community ecology may be beneficial for a better understanding of the processes that regulate species coexistence.     

A new species of Bricelochlorops Paganelli and the first record of Urubambina rufa (Duda) (Diptera: Chloropidae) from Brazil

The subfamily Chloropinae comprises about 442 described species, with only one species recorded from the Brazilian Amazon. The genus Bricelochlorops Paganelli was represented by a unique species from Rio de Janeiro, Brazil. The species Urubambina rufa (Duda) is the only species of the genus Urubambina Paganelli and has been recorded only from Peru. A new species of Bricelochlorops, B. celutae sp. nov., is described here and Urubambina rufa is recorded for the first time in Brazil. Both species were collected in the state of Acre. A key to species of Bricelochlorops is provided.     

Dynamics of Intraguild Predation Systems with Intraspecific Competition

This paper considers intraguild predation (IGP) systems where species in the same community kill and eat each other and there is intraspecific competition in each species. The IGP systems are characterized by a lattice gas model, in which reaction between sites on the lattice occurs in a random and independent way. Global dynamics of the model with two species demonstrate mechanisms by which IGP leads to survival/extinction of species. It is shown that an intermediary level of predation promotes survival of species, while over-predation or under-predation could result in species extinction. An interesting result is that increasing intraspecific competition of one species can lead to extinction of one or both species, while increasing intraspecific competitions of both species would result in coexistence of species in facultative predation. Initial population densities of the species are also shown to play a role in persistence of the system. Then the analysis is extended to IGP systems with one species. Numerical simulations confirm and extend our results.     

稀有种和常见种对植物群落物种丰富度格局的相对贡献

物种丰富度格局的形成不仅依赖于群落的构建过程, 同样也依赖于群落中的物种组成(如稀有种和常见种)。本文以黄土高原子午岭林区的辽东栎(Quercus wutaishanica)林为研究对象, 根据频度大小对物种进行排序, 形成稀有-常见种和常见-稀有种两条物种序列, 通过逐一添加(去除)物种, 分析引起的总体物种丰富度及其成分(α多样性和β多样性)的变化, 确定稀有种和常见种对物种丰富度格局的相对贡献。结果表明: (1)常见-稀有种序列与群落总体物种丰富度的相关性呈先剧增后平稳的对数增长曲线, 而稀有-常见种序列与群落总体的相关性与前者刚好相反, 呈先平稳后剧增的指数增长曲线; (2) α多样性在常见-稀有种序列中呈明显的对数变化曲线, 而在稀有-常见种序列中呈指数增长曲线; (3)与α多样性变化相反, β多样性在常见-稀有种序列中随物种的进入先迅速降低后逐渐平稳, 而在稀有-常见种序列中先平稳后急剧降低。可以看出, 常见种不仅主导群落的总体物种丰富度格局, 同时也是α多样性和β多样性格局的重要贡献者。因此, 常见种是群落物种丰富度格局的指示者, 也应该是优先保护的物种。     

Species: the concept, category and taxon

The term species by itself is vague because it refers to the species concept, the species category and the species taxon, all of which are distinct although related to one another. The species concept is not primarily a part of systematics, but has always been an integral part of basic biological theory, It is based on evolutionary theory and applies only to sexually reproducing organisms. The species concept and the phyletic lineage concept are quite distinct although they are related to one another. The important aspect of the species concept is lack of gene flow between different species, and hence the defining criterion of the species is genetic isolation. The species concept is often considered as non‐dimensional, both in time and space. Species possess three different major properties, namely genetic isolation, reproductive isolation and ecological isolation; these properties evolve at different times and under the effect of different causes during the speciation process. Speciation requires an external isolating barrier during the initial allopatric phase in which genetic isolation evolves and must reach 100% efficiency. The subsequent sympatric phase of speciation occurs after the disappearance of the external isolating barrier when members of the two newly evolved species can interact with one another and exert mutual selective demands on one another. Much of the reproductive and ecological isolation evolves during this secondary sympatric phase. The species category is a rank in the taxonomic hierarchy and serves as the basis on which the diversity of organisms is described; it is not the same as the species concept. The species category applied to all organisms, sexually and asexually reproducing. The species taxon is the practical application of the species category in systematics with the recognition of species taxa requiring many arbitrary decisions. No single set of rules exist by which the species category can be applied to all organisms. Recognition of species taxa in asexually reproducing organisms is based on amount of variation and gaps in the variation of phenotypic features associated with ecological attributes of these organisms as compared with similar attributes in sympatric species taxa of sexually reproducing organisms. Species taxa are multidimensional in that they exist over space–time and often have fuzzy borders. Because recognition of species taxa, including those in sexually reproducing organisms, depends on many arbitrary decisions especially when dealing with broad geographical and temporal ranges, species taxa cannot be used as the foundation for developing and testing theoretical concepts in evolutionary theory which can only be done with the non‐dimensional species concept.     

Body size and measurement of species diversity in large grazing mammals

Species are by definition different from each other. This fact favours ranking rather than additive indices. However, ecologists have measured species diversity in terms of species richness, or by combining species richness with the relative abundance of species within an area. Both methods raise problems: species richness treats all species equally, while relative abundance is not a fixed property of species but varies widely temporally and spatially, and requires a massive sampling effort. The functional aspect of species diversity measurement may be strengthened by incorporating differences between species such as body size as a component of diversity. An index of diversity derived from a measure of variation in body size among species is proposed for large grazing mammals. The proposed diversity index related positively to species abundance, indicating that the use of body size as a surrogate for diversity is adequate. Because the proposed index is based on presence or absence data, the expensive and time consuming counting of individuals per species in each sampling unit is not necessary.     

西双版纳地区不同植被亚型蚁科昆虫群落研究

研究了西双版纳地区１６各被亚型蚂蚁的特有种、优势种、物种多样性指数、均匀度指数、优势度指数和相似性系数。所采蚂蚁分隶于８亚科６６属２２０种。雨季的季节性十麻蚂蚁物种多样性指数最大,为２．９０８;旱季的茶园中多样性指数最小,为０．１１４。以山地雨林和季风常绿阔叶林蚂蚁物各组成相似性系数最大,为０．３５６;以温暖性叶阔叶林和茶园相似性系数最小,为０．０１７。１６种植被亚型均有特有种,其中半常绿季雨林特     

Correlated Non-native Species Richness of Birds, Mammals, Herptiles and Plants: Scale Effects of Area, Human Population and Native Plants

Several extrinsic factors (area, native species diversity, human population size and latitude) significantly influence the non-native species richness of plants, over several orders of magnitude. Using several data sets, I examine the role of these factors in non-native species richness of several animal groups: birds, mammals and herptiles (amphibians, reptiles). I also examine if non-native species richness is correlated among these groups. I find, in agreement with Sax [2001, Journal of Biogeography 28: 139–150], that latitude is inversely correlated with non-native species richness of many groups. Once latitude is accounted for, area, human population size and native plant species richness are shown to be important extrinsic factors influencing non-native animal species. Of these extrinsic factors, human population size and native plant species richness are the best predictors of non-native animal species richness. Area, human population size and native plant species richness are highly intercorrelated, along with non-native species richness of all taxa. Indeed a factor analysis shows that a single multivariate axis explains over half of the variation for all variables among the groups. One reason for this covariation is that humans tend to most densely occupy the most productive and diverse habitats where native plant species richness is very high. It is thus difficult to disentangle the effects of human population size and native species richness on non-native species richness. However, it seems likely that these two factors may combine to increase non-native species richness in a synergistic way: high native species richness reflects greater habitat variety available for non-native species, and dense human populations (that preferentially occupy areas rich in native species) increase non-native species importation and disturbance of local habitats.     

庐山蛾类区系研究

庐山,地处中亚热带北沿,北纬29.35°,东经115.59°,属亚热带东部季风区域。庐山襟江带湖,雨量充沛,植物种类繁多,种子植物有1800余种,隶属158科642属。因此,庐山蛾类也较丰富。笔者于1975年5月开始,对庐山蛾类进行了调查,共鉴定出蛾类455种。现将庐山蛾类区系报告如下。 区系分析 庐山蛾类已鉴定出32科340届455种。区系情况如表。 从表可以看出:     

Eye size variation reflects habitat and daily activity patterns in colubrid snakes

The functioning of the vertebrate eye depends on its absolute size, which is presumably adapted to specific needs. Eye size variation in lidless and spectacled colubrid snakes was investigated, including 839 specimens belonging to 49 genera, 66 species and subspecies. Variations of adult eye diameters (EDs) in both absolute and relative terms between species were correlated with parameters reflecting behavioral ecology. In absolute terms, eye of arboreal species was larger than in terrestrial and semiaquatic species. For diurnal species, EDs of terrestrial species do not differ from semiaquatic species; for nocturnal species the ED of terrestrial species is larger than fossorial species but not different from semiaquatic species. In relative terms, ED did not differ significantly by habitat for diurnal species. Although the ED of terrestrial species is larger than fossorial species there were no differences for nocturnal species between semiaquatic and fossorial snakes. In contrast to other vertebrates studied to date, colubrid EDs in absolute and relative terms are larger in diurnal than in nocturnal species. These observations suggest that among colubrid snakes, eye size variation reflects adaptation to specific habitats, foraging strategies and daily activities, independently of phylogeny. J. Morphol. 2012. © 2012 Wiley Periodicals, Inc.     

Does energy availability influence classical patterns of spatial variation in exotic species richness?

Aim At macroecological scales, exotic species richness is frequently positively correlated with human population density. Such patterns are typically thought to arise because high human densities are associated with increased introduction effort and/or habitat modification and disturbance. Exotic and native species richness are also frequently positively correlated, although the causal mechanisms remain unclear. Energy availability frequently explains much of the variation in species richness and we test whether such species–energy relationships may influence the relationships of exotic species richness with human population density and native species richness. Location Great Britain. Methods We first investigate how spatial variation in the distributions of the 10 exotic bird species is related to energy availability. We then model exotic species richness using native avian species richness, human population density and energy availability as predictors. Species richness is modelled using two sets of models: one assumes independent errors and the other takes spatial correlation into account. Results The probability of each exotic species occurring, in a 10‐km quadrat, increases with energy availability. Exotic species richness is positively correlated with energy availability, human population density and native species richness in univariate tests. When taking energy availability into account, exotic species richness is negligibly influenced by human population density, but remains positively associated with native species richness. Main conclusions We provide one of the few demonstrations that energy availability exerts a strong positive influence on exotic species richness. Within our data, the positive relationship between exotic species richness and human population density probably arises because both variables increase with energy availability, and may be independent of the influence of human density on the probability of establishment. Positive correlations between exotic and native species richness remain when controlling for the influence of energy on species richness. The relevance of such a finding to the debate on the relationship between diversity and invasibility is discussed.     

Is a unified concept of species in ornithology possible? (An opinion of a practicing taxonomist)]

An analysis of current publications on species problem reveals the radical discrepancy between the statements of species reality in nature and different number of these "realities" in light of different species concepts. It has been shown, that the only realities are populations, and "species" is only logical construct--the notion. A concept of species is a system of interconnected notions, where the main element--ontology of species has been always given a priori to the real biodiversity. For that reason every concept of species creates its own "virtual reality". Various concepts of species are not mutually comparable, and can not be criticized from each other's views and from position of "reality". Biological and Phylogenetic Species Concepts competing in ornithology exclude each other completely, and the unified concept of species is principally impossible. But as generally accepted species "standard" is needed, the unified convention of species must take the place of the various concepts of species.     

北京湿地维管植物区系研究

记录了分布于北京地区的典型湿地维管植物266种7变种1变型,共274个分类群,隶属于58科144属。从种一级的水平对这274个分类群进行分析,可分为14个分布区类型,其中温带性质的种187种,为整个区系成分的主体,另有世界广布种45种,热带性质的种30种,中国特有种12种。就北京湿地维管植物区系特征而言,其种类组成与华北其他地区湿地存在着相似性,温带成分占优势地位,并存在一些古老孑遗种类及特有种。此外,还对区系成分中的受危种和外来种进行了讨论。