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:     

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.     

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.     

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.     

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.     

Infusing considerations of trophic dependencies into species distribution modelling

Community ecology involves studying the interdependence of species with each other and their environment to predict their geographical distribution and abundance. Modern species distribution analyses characterise species‐environment dependency well, but offer only crude approximations of species interdependency. Typically, the dependency between focal species and other species is characterised using other species’ point occurrences as spatial covariates to constrain the focal species’ predicted range. This implicitly assumes that the strength of interdependency is homogeneous across space, which is not generally supported by analyses of species interactions. This discrepancy has an important bearing on the accuracy of inferences about habitat suitability for species. We introduce a framework that integrates principles from consumer–resource analyses, resource selection theory and species distribution modelling to enhance quantitative prediction of species geographical distributions. We show how to apply the framework using a case study of lynx and snowshoe hare interactions with each other and their environment. The analysis shows how the framework offers a spatially refined understanding of species distribution that is sensitive to nuances in biophysical attributes of the environment that determine the location and strength of species interactions.     

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.     

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.     

What do the biodiversity experiments tell us about consequences of plant species loss in the real world?

Experiments where the diversity of species assemblage is manipulated are sometimes used to predict the consequences of species loss from real communities. However, their design corresponds to a random selection of the lost species. There are three main factors that limit species richness: harshness of the environment, competitive exclusion, and species pool limitation. Species loss is usually caused by increasing effects of these factors. In the first two cases, the species that are excluded are highly non-random subsets of the potential species set, and consequently, the predictions based on random selection of the lost species might be misleading. The data show that the least productive species are those being recently excluded from temperate grasslands and consequently, species loss is not connected with decline of productivity. The concurrent species loss in many communities, however, means also a reduction of the available diaspore pool on a landscape scale, and could result in increased species pool limitation in other communities.     

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。     

Ecological and trophic differentiation of fungal diversity in Aksu-Zhabagly Nature Reserve (Kazakhstan)

Two fungal-like organisms (class Oomycetes) and 263 species of fungi from 111 genera, 42 families, 23 orders, and 7 classes have been found on the territory of Aksu-Zhabagly Nature Reserve. Twenty-two species are found for the first time. The vast majority of species are parasitic (202 species), 56 species belong to saprotrophs, and 7 to symbiotrophs. Classes Taphrinomycetes, Urediniomycetes, and Ustilaginomycetes are represented exclusively by parasites. There have been found 21 saprotrophic, 27 parasitic, and 4 symbiotrophic species in the class Ascomycetes. The most numerous group in the class Basidiomycetes is the group of humus saprotrophs; it contains 15 species. Groups of litter saprotrophs and parasites contain four species each, symbiotrophic species have three species, coprotrophs and xylotrophs have two species each, and litter and humus saprotrophs have one species each. Anamorphic fungi are represented by 91 parasitic and 11 saprotrophic species. In comparison with closely located Sairam-Ugam National Park and the Karatau Nature Reserve, the mycobiota of Aksu-Zhabagly is characterized by a significant number of species in the classes Basidiomycetes, Urediniomycetes, Hyphomycetes, and Coelomycetes. Thirty-one species are common to these protected areas. The most numerous group is parasites.     

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.     

Relative influence of habitat heterogeneity, climate, human disturbance, and spatial structure on vertebrate species richness in Spain

Many factors affect the distribution of species richness. This study examines the relative influence of habitat heterogeneity, climate, human disturbance, and spatial structure on the species-richness distribution of terrestrial vertebrates (amphibians, reptiles, birds and mammals) in mainland Spain. The results indicate that spatial structure and environment exert similar influences on species richness. For all four taxa, species richness increases southward and northward, being lower in the center of the country, when controlled for other variables. This may be the result of a peninsular effect, as found in other studies, and reflect the importance of historical events on species richness in the Iberian Peninsula. Climate is more important than habitat heterogeneity in determining species richness. Temperature is positively correlated with amphibian, reptile, and bird species richness, while mammalian species richness is highest at intermediate temperatures. This effect is stronger in ectotherms than among endotherms, perhaps reflecting physiological differences. Precipitation positively correlates with bird and mammalian species richness, but has no effect on ectotherm species richness. Amphibian species richness increases with altitudinal range, and bird species richness with habitat diversity. Human population density is positively correlated with bird and mammalian species richness, but does not affect ectotherm species richness, while amphibian and bird species richness is highest at moderate levels of human land alteration (farmland). However, unexplained variance remains, and we discuss that the effects of environmental variables on species richness may vary geographically, causing different effects to be obscured on a national scale, diminishing the explanatory power of environmental variables.     

中国台湾和大陆蹄盖蕨属植物的生物地理学比较

蹄盖蕨属Athyrium Roth是个典型的东亚属,全世界估计约有160种,主要分布在亚洲东部的亚热带高山,少数在温带其他地区,中国有117种,是其分布中心。台湾和大陆的蹄盖蕨属植物关系尤为密切,是研究海峡两岸植物地理关系的一个很好的材料。台湾已知共计有蹄盖蕨类植物32种,包括狭义蹄盖蕨27种,介蕨2种,蛾眉蕨1种,假蹄盖蕨1种,假冷蕨1种,即使将待查实的4种蹄盖蕨除去,至少还有28种。其中除去7种大陆不产外, 21种均和大陆共有,占75%。况且,这7种与大陆种形态相近,是否同种异名、亚种或姊妹种关系还有待进一步研究;在台湾和大陆共有的16种狭义蹄盖蕨中有7种是台湾-西南间断分布。这不仅说明了台湾的蹄盖蕨属类植物和大陆的关系密切、有着共同的起源,而且说明台湾高地的植物区系和西南高地关系最为密切。运用生物系统学和分子系统学的方法研究和测定海峡两岸共有种种内、姊妹种或近缘种之间的遗传学关系(如:遗传一致度),进一步了解并量化台湾和大陆植物区系之间的历史和地理关系是必要的。     

The number of species of rodent coccidia and of other protozoa

About 447 species of coccidia have been named from the 1687 living, known species of rodents; 207 host species, 92 host genera, and 15 host families are represented; this is about 12% of the known species of rodents. About 4600 species of apicomplexan protozoa have been named. Assuming that the same proportion of the total number of apicomplexan species has been named as of the coccidian species, there must actually be about 38,333 species of apicomplexan protozoa. There are 5.4 times as many protozoan genera as of apicomplexan genera. Assuming that the number of species in each genus is the same for all the protozoa as it is for the Apicomplexa, there may actually be 206,998 species of protozoa. This may be too conservative an estimate. Based on other criteria, an estimate of over 20 million species could be made.     

The statistical mechanics of community assembly and species distribution

? Theoretically, communities at or near their equilibrium species number resist entry of new species. Such 'biotic resistance' recently has been questioned because of successful entry of alien species into diverse natural communities. ? Data on 10,409 naturalizations of 5350 plant species over 16 sites dispersed globally show exponential distributions both for species over sites and for sites over number of species shared. These exponentials signal a statistical mechanics of species distribution, assuming two conditions. First, species and sites are equivalent, either identical ('neutral') or so complex that the chance a species is in the right place at the right time is vanishingly small ('idiosyncratic'); the range of species and sites in our data disallows a neutral explanation. Secondly, the total number of naturalizations is fixed in any era by a 'regulator'. ? Previous correlation of species naturalization rates with net primary productivity over time suggests that the regulator is related to productivity. ? We conclude that biotic resistance is a moving ceiling, with resistance controlled by productivity. The general observation that the majority of species occur naturally at only a few sites, and only a few species occur at many sites, now has a quantitative (exponential) character, offering the study of species' distributions a previously unavailable rigor.     

Food web structure and interaction strength pave the way for vulnerability to extinction

This paper focuses on how food web structure and interactions among species affects the vulnerability, due to environmental variability, to extinction of species at different positions in model food webs. Vulnerability is here not measured by a traditional extinction threshold but is instead inspired by the IUCN criteria for endangered species: an observed rapid decline in population abundance. Using model webs influenced by stochasticity with zero autocorrelation, we investigate the ecological determinants of species vulnerability, i.e. the trophic interactions between species and food web structure and how these interact with the risk of sudden drops in abundance of species. We find that (i) producers fulfil the criterion of vulnerable species more frequently than other species, (ii) food web structure is related to vulnerability, and (iii) the vulnerability of species is greater when involved in a strong trophic interaction than when not. We note that our result on the relationship between extinction risk and trophic position of species contradict previous suggestions and argue that the main reason for the discrepancy probably is due to the fact that we study the vulnerability to environmental stochasticity and not extinction risk due to overexploitation, habitat destruction or interactions with introduced species. Thus, we suggest that the vulnerability of species to environmental stochasticity may be differently related to trophic position than the vulnerability of species to other factors. Earlier research on species extinctions has looked for intrinsic traits of species that correlate with increased vulnerability to extinction. However, to fully understand the extinction process we must also consider that species interactions may affect vulnerability and that not all extinctions are the result of long, gradual reductions in species abundances. Under environmental stochasticity (which importance frequently is assumed to increase as a result of climate change) and direct and indirect interactions with other species some extinctions may occur rapidly and apparently unexpectedly. To identify the first declines of population abundances that may escalate and lead to extinctions as early as possible, we need to recognize which species are at greatest risk of entering such dangerous routes and under what circumstances. This new perspective may contribute to our understanding of the processes leading to extinction of populations and eventually species. This is especially urgent in the light of the current biodiversity crisis where a large fraction of the world's biodiversity is threatened.