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1.
Studies on the moss mites of Snowdonia (Acari: Oribatei). 2. The Cnicht   总被引:1,自引:0,他引:1  
A faunal list of oribatid mites collected from the summit of the Cnicht, Snowdonia, at 2265 ft is given, together with critical notes on the taxonomy and distribution of several of the species. The list provides further evidence of the presence of arctic-alpine and European-alpine species of Oribatei on the mountain peaks of Britain. A comparison of the faunal list with lists of species recorded by the author on another peak in Snowdonia and on high ground in other parts of Britain (Peak District, Lake District) and by Block in Westmorland, provides evidence of a group of additional species which can be regarded as characteristic of upland areas in general of Britain and Europe.  相似文献   

2.
于2005年9月~12月对湘江株洲江段的软体动物进行了系统的调查.经分类鉴定,计有软体动物8科20属44种,其中腹足纲5科10属22种,双壳纲3科10属22种.腹足纲以田螺科为主,双壳纲以蚌科为主.其区系成分,东洋界与古北界相互渗透,但以东洋界华中区的种类优势明显.沿江城镇适量生活污水排入江中,可以适当增加软体动物的种类和数量;大量生活污水和工业废水未经处理排入江中,使其种类和数量显著减少.株洲航电枢纽建成蓄水,对库区的软体动物冲击较大,由于水位抬高,环境骤变,其种类和种群数量明显减少,尤其是双壳类.  相似文献   

3.
Salt and water balance in the Aral Sea are described together with the endemic fauna and flora which were mainly of freshwater origin. During the last thirty years the fauna and flora have undergone dramatic changes due partly to a great increase in salinity as the result of water abstraction from the inflowing rivers and partly as the result of the deliberate and accidental introduction of a wide variety of marine invertebrates and fishes. The increased salinity has eliminated most the species of freshwater origin while many of endemic saline species have been lost as the result of competition with the marine ones. Changes in productivity are described and future prospects for the sea are discussed.  相似文献   

4.
A multiple regression analysis was performed upon selected environmental variables for a series of islands in the British Isles, to establish their effects upon the size of the butterfly fauna, measured as he number of species regularly breeding, SB. So that the data be normally distributed, the regression analyses were performed upon log10 transformed data only, with the data for outliers, mainland Britain and Ireland, the two largest islands, excluded. Most highly correlated with the number of butterfly species breeding upon an island is the number breeding within a 25 km radius of the nearest point of the mainland, r2=0.5941, followed by the correlations with the latitude of the mid-point of the island, r2=0.5541, the number of plant species comprising the island Hora, r2=0.5225, and the distance separating the island from the mainland, r2=0.4514. A partial correlation analysis confirms the importance of the parameters distance separating the island from the mainland, D1, and the size of the faunal source SF, and rejects the importance of the size of the flora and the latitude of the island. This is further confirmed by the results of a step-wise regression analysis, the two variables D1 and SF accounting for 66% of the variation of the butterfly fauna. If an alternative measure of isolation, D2, which allows for the geographical clumping of islands, is combined with the variable SF, then 69% of the variation of the butterfly fauna is accounted for.  相似文献   

5.
A multiple regression analysis was performed upon selected environmental variables for a series of islands in the British Isles, to establish their effects upon the size of the butterfly fauna, measured as he number of species regularly breeding, SB .
So that the data be normally distributed, the regression analyses were performed upon log10 transformed data only, with the data for outliers, mainland Britain and Ireland, the two largest islands, excluded.
Most highly correlated with the number of butterfly species breeding upon an island is the number breeding within a 25 km radius of the nearest point of the mainland, r 2=0.5941, followed by the correlations with the latitude of the mid-point of the island, r 2=0.5541, the number of plant species comprising the island Hora, r 2=0.5225, and the distance separating the island from the mainland, r 2=0.4514.
A partial correlation analysis confirms the importance of the parameters distance separating the island from the mainland, D 1, and the size of the faunal source S F , and rejects the importance of the size of the flora and the latitude of the island. This is further confirmed by the results of a step-wise regression analysis, the two variables D 1 and SF accounting for 66% of the variation of the butterfly fauna.
If an alternative measure of isolation, D 2, which allows for the geographical clumping of islands, is combined with the variable SF , then 69% of the variation of the butterfly fauna is accounted for.  相似文献   

6.
Abstract. 1. Data are presented on the species richness and faunal composition of herbivorous insects on birch seedlings, saplings and trees at one site in Northern England.
2. Species richness of insect herbivores in equal-sized samples from birch seedlings and trees was similar through most of the season.
3. Effects of plant architecture were confined to the first sampling date, when seedling faunas were species poor compared with trees – possibly due to safe overwintering sites on the extensive bark, twigs and buds of trees.
4. The faunal composition of birch seedlings, saplings and trees was also similar. Out of a total of 112 recorded species of herbivores, only one aphid species was confined to seedlings.
5. Similarly, no evidence for clear-cut vertical stratification of insects within trees was found.
6. Species turnover as host plants mature ('horizontal' stratification) and vertical stratification within trees add little to the high overall species richness of birch-feeding insects in Britain, contrary to the predictions of Lawton (1983).  相似文献   

7.
ABSTRACT. The butterfly assemblages of three vegetation types (pasture, heathland and rocky outcrop with Genista spp.) and two geographical orientations (a northern slope and a sheltered gorge) were studied along an altitudinal gradient in the Picos de Europa in northern Spain. In order to study the effects or historical climatic changes on current butterfly assemblages, it was examined if changes in richness and faunal composition of assemblages were joined with changes in their biogeographical composition. The three vegetation types showed characteristic butterfly assemblages, but no difference in species richness and biogeographical composition was found. Species richness in the sheltered gorge was higher than in the northern slope. Faunal composition also varied between orientations and there were more widespread and Mediterranean species in the sheltered gorge than in the northern slope. Species richness declined with increasing altitude, though a midaltitudinal peak was observed. There was a faunal segregation between high and low localities. Species richness of widespread and Mediterranean butterflies decreased as altitude increased, whereas the reverse was true for montane species. Moreover, biogeographical elements differed in their climatic tolerances measured as altitudinal ranges. Therefore, changes in richness and composition of butterfly assemblages between both slopes and along the altitudinal gradient were joined in part with variation in their biogeographical composition. These results suggest that current species richness and composition of butterfly assemblages in the Picos de Europa might be the consequence of differential colonization of refuges during the past climatic changes.  相似文献   

8.
I analyzed stomach contents of the American bullfrog, Rana catesbeiana, in the Mizorogaike Pond of Kyoto, Japan. As a result, adult bullfrogs were found to feed predominantly on crayfish, and juveniles eat diverse arthropods. A wide variety of aquatic organisms occurred in the diet of both adult and juvenile bullfrogs.  相似文献   

9.
A faunal list of oribatid mites collected from the summit of the Cheviot, Northumberland, is given, together with notes on the taxonomy and distribution of several of the species. Special attention is paid to the Arctic-alpine and European-alpine species and the list provides further support for the view that the upland areas of Britain are characterized by a common group of oribatid species. It is suggested that these species may be cold hardy or cold tolerant with relatively high supercooling points, enabling them to survive the winter at these higher altitudes.  相似文献   

10.
根据2004—2005年大亚湾海域底拖网鱼类调查数据,并结合1980—2007年的历史资料,分析了该海域鱼类的种类组成、区系特征、多样性、优势种和数量变化趋势.结果表明: 2004—2005年,大亚湾海域共记录鱼类107种,分属13目50科,以中下层鱼类的种类最多,为48种,其次是中上层和底层种类,分别为37种和21种.大亚湾鱼类区系具热带和亚热带特性,以暖水性种类占绝对优势,为97种,暖温性种类为10种.多样性指数以夏季最高(3.82),其次是冬季(3.37)和秋季(3.00),春季最低(2.40).Pielou均匀度指数的季节变化情况与多样性指数相似.1980—2007年大亚湾海域鱼类群落特征发生了明显的变化:鱼类种类数减少,优势种更替明显.鱼类种类数由1980年的157种减少至1990年的110种,2004—2005年继续减少至107种;鱼类优势种由1980年以带鱼和银鲳等优质鱼为主,更替为以小型和低值的小沙丁鱼、小公鱼和二长棘鲷幼鱼为主.用包含年际变化趋势和季节性周期变化的回归模型模拟1980—2007大亚湾鱼类资源密度的变化,鱼类资源密度在1980—1999年和1990—2007年两个时期均呈下降趋势,但1990—2007年间下降幅度比1980—1999年间大;1980—1999年鱼类资源密度的季节波动幅度较平缓(振幅为0.099),而1990—2007年的季节波动较大(振幅为0.420),说明1990—2007年阶段大亚湾鱼类数量的季节变化更为显著.  相似文献   

11.
莽山自然保护区陆生贝类的种类组成及区系分析   总被引:3,自引:0,他引:3  
首次报道了莽山自然保护区陆生贝类39种,隶属于2亚纲、10科、19属;介绍了莽山的自然概况;对莽山自然保护区陆生贝类的种类组成、区系特点、生态分布与栖息环境之间的关系进行了分析。  相似文献   

12.
Pollock DA 《ZooKeys》2012,(188):1-153
The Nearctic fauna (north of Mexico) of Eustrophinae is reviewed, and consists of the following five genera and 12 species: Pseudoholostrophus (Pseudoholostrophus) impressicollis (LeConte), Pseudoholostrophus (Holostrophinus) discolor (Horn), Holostrophus bifasciatus (Say), Eustrophus tomentosus Say, Eustrophopsis confinis (LeConte), Eustrophopsis bicolor (Fabricius), Eustrophopsis brunneimarginatus (Dury), Eustrophopsis indistinctus (LeConte), Eustrophopsis arizonensis (Horn), Eustrophopsis ornatus (Van Dyke), Eustrophopsis crowdyisp. n., and Synstrophus repandus (Horn). A lectotype is designated for Eustrophus brunneimarginatus Dury. A key is given to separate genera and species, supplemented with illustrations of relevant features, including aedeagi of all Nearctic species of Eustrophopsis. Detailed distribution (including Mexican records) and natural history data are provided.  相似文献   

13.
Abstract. To determine the generality of avian diversity patterns, we investigated patterns of elevational zonation shown by birds and mammals along the eastern slope of the Andes Mountains in southeastern Peru. The strong environmental gradient sampled, entirely within Peru's Manu National Park and Biosphere Reserve, supports highly diverse faunas. Elevational distributions of 901 bird species, 129 bat species, and twenty-eight species of native mice exhibit contrasting patterns in species richness, species composition, and species turnover. Birds and bats showed smooth declines of species richness with elevation, whereas the richness of mouse assemblages was unrelated to elevation. For all three groups, the greatest differences were between lowland and highland faunas, although cutoff points for this contrast varied among groups (≈ 500 m for birds, 750 m for bats, and 1000 m for mice). Differences in composition also separated bird and bat faunas on either side of c. 1400 m (the boundary between montance forest and cloud forest); for mice, this faunal transition may take place nearer to 2000 m. Bird and bat faunas lacked the more discrete zonations suggested for mouse assemblages, as indicated by elevational range profiles and nested subset analyses. Distinct highland assemblages are apparent in two-dimensional histograms of range limits of birds and mice, but not for bats. Highland bat species occupy broader elevational ranges than lowland bat species, but for both birds and mice, species at intermediate elevations had the broadest amplitudes. Finally, clumping of range maxima and minima along the gradient identified zones of pronounced species turnover in each group, but these were generally not strongly associated with the locations of ecotones. Differences in zonation of these groups appear to reflect their different biological attributes and phylogenetic histories. Such differences obviously complicate discussions of ‘general’ diversity patterns, and limit the usefulness of birds to forecast or predict diversity patterns in other more poorly known groups—other groups may show elevated diversity and endemism in areas where avian diversity patterns appear unremarkable. The pronounced contrasts between bats and mice, and the generally intermediate character of avian patterns, suggest that future analyses might profitably partition birds into finer, more homogeneous groups of historically and/or ecologically similar species. Group differences in zonation may ultimately prove explicable with information on both species-abundance patterns and resource distributions.  相似文献   

14.
湘江中游江段螺类的种类组成及区系分析   总被引:6,自引:0,他引:6  
报道了湘江中游江段螺类的调查结果,计有螺类31种(其中5种为湖南省新记录),分别隶属于腹足纲6科11属,其中主要是田螺科的种类.对它们的种类组成、区系、种群大小、分布与栖息环境的关系进行了分析,并讨论了城镇污水未经处理直接排放及修河拦坝对螺类生存环境的影响.  相似文献   

15.
From tracking Antelope and other species in Kenya as a child, Per Christensen went on to train in ecology and participate in many of the key small mammal reintroduction programs in Western Australia. What lessons can be gleaned from these experiences for current and future restoration ecology?  相似文献   

16.
An inventory of the fish species composition of the community from Baidaratskaya Bay in the Kara Sea was performed. On the basis of published data and the results of our own studies, the dynamics of changes in the species composition of marine ichthyocenosis of Baidaratskaya Bay from 1932 to 2007 was analyzed. Differences in qualitative (occurrence) and quantitative (proportion in catches) characteristics are shown.  相似文献   

17.
珠江口附近海区甲壳类动物的区系特征及其分布状况   总被引:4,自引:0,他引:4  
根据2006年8月(夏季)、2006年10月(秋季)、2006年12月(冬季)和2007年4月(春季)珠江口附近海区的底拖网调查资料,分析了该海域甲壳类动物的区系特征和分布状况.结果表明:本次调查共采获甲壳类动物54种,分隶于2目17科25属,其中,虾类22种、蟹类22种、虾蛄类10种;该海域甲壳类动物多数为热带 亚热带的暖水性种类,少数为广温性种类,未出现暖温性和冷温性种类;广盐性的种类最多,其次为高盐性种类,低盐性种类最少;大多数种类属于印度洋 西太平洋区系;调查海域的甲壳类动物种类与东海、菲律宾海、印度尼西亚海、日本海关系较密切,与黄海、渤海、朝鲜海关系较疏远.调查海域甲壳类动物的优势种为周氏新对虾、口虾蛄、武士蟳、红星梭子蟹、猛虾蛄、锈斑蟳、日本蟳、长叉口虾蛄、中华管鞭虾、三疣梭子蟹和逍遥馒头蟹.出现的种类数以秋季最多(33种),春季最少(26种).甲壳类资源密度在水深0~40 m水域较高,在水深10~20 m最密集.调查海域甲壳类动物的平均资源密度为99.60 kg·km-2,以夏季最高(198.93 kg·km-2)、春季最低(42.35 kg·km-2);组成甲壳类动物的3个类群中,蟹类的资源密度最高(41.81 kg·km-2),其次是虾类(38.91 kg·km-2),虾蛄类最低(18.88 kg·km-2);各类群资源密度存在明显的季节变化,虾类在夏季最高(120.32 kg·km-2)、春季最低(0.67 kg·km-2),蟹类和虾蛄类则均在冬季最高(62.01和29.49 kg·km-2)、秋季最低(24.64和6.30 kg·km-2).  相似文献   

18.
湖南莽山国家级自然保护区蛇类的多样性   总被引:1,自引:0,他引:1  
陈远辉 《四川动物》1998,17(2):86-90
本文报道1988-1996年在湖南莽山国家级自然保护区一带采集和记录到蛇类标本750余号46种,隶4科25属。综合原有记录,莽山地区一带蛇类资源现共记录到4科27属50种。  相似文献   

19.
20.
Aim To delineate biogeographical patterns in Galapagos shallow‐water reef fauna at regional scales. Location Galapagos Islands. Methods Fishes and macro‐invertebrates were quantitatively censused using underwater visual techniques along more than 500 transects at defined depth strata across the Galapagos archipelago. Data were analysed using multivariate techniques to define regional patterns and identify species typical of different regions. Results Subtidal communities of fishes and macro‐invertebrates on shallow reefs differed consistently in species composition across the Galapagos archipelago, with three major biogeographical groupings: (1) the ‘far‐northern area’ containing the islands of Darwin and Wolf, (2) the ‘central/south‐eastern area’, including the east coast of Isabela, and (3) the ‘western area’, encompassing Fernandina and western Isabela. In addition, the northern islands of Pinta, Marchena and Genovesa form a separate region in the central/south‐eastern area, and Bahia Elizabeth and Canal Bolivar separate from other parts of the western area. The far‐northern bioregion is characterized by high fish species richness overall, including a high proportion of species of Indo‐Pacific origin. However, very few endemic fishes or species with distributions extending south from Ecuador (‘Peruvian’ species) are present, and the bioregion also possesses relatively low species richness of mobile macro‐invertebrate taxa. By contrast, the ‘western’ bioregion possesses disproportionately high numbers of endemic fish taxa, high numbers of cool‐temperate Peruvian fish species, and high invertebrate species richness, but very few species of Indo‐Pacific origin. The Bahia Elizabeth/Canal Bolivar bioregion possesses more endemic species and fewer species with Peruvian affinities than coasts within the western bioregion. The northern bioregion of Pinta, Marchena and Genovesa represents an overlap zone with affinities to both the far‐northern and south‐eastern islands. The south‐eastern bioregion includes species from a variety of different sources, particularly ‘Panamic’ species with distributions extending north to Central America. Main conclusions On the basis of congruent divisions for reef fish and macro‐invertebrate communities, the Galapagos archipelago can be separated into three major biogeographical areas, two of which can be further subdivided into two regions. Each of these five bioregions possesses communities characterized by a distinctive mix of species derived from Indo‐Pacific, Panamic, Peruvian and endemic source areas. The conservation significance of different regions is not reflected in counts of total species richness. The regions with the lowest overall fish species richness possess a temperate rather than tropical climate and highest levels of endemism.  相似文献   

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