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1.
The basic tendencies of territorial changes in bird communities of the middle taiga on the Central Siberian Plateau are interrelated with the differences in forestation, productivity, swampiness, bushiness, watering, and buildup of habitats and are on the whole similar to those on the West Siberian and Central Yakutsk plains, although there are also some differences. Thus, the community types of upland swamps and low-inundated meadows in combination with lowland swamps are characteristic only of West Siberia. In Central Siberia, forest ornithocomplexes are the most diverse, which is largely due to the presence of communities of woodlands and glades at different stages of overgrowing. The ecotone type of ornithocomplexes was distinguished only for Central Yakutia. In the North Urals, the formation of ornithocomplexes is significantly influenced by forestation and tree species composition but starts to be noticeably affected by altitudinal zonality as well as productivity of biocenoses and development of shrubs in habitats interrelated with this factor.  相似文献   

2.
The classification of South Siberian meadows using the Braun-Blanquet approach was carried out on the basis of a geographically wide-ranging data set from the West Siberian Plain and the Altai-Sayanian mountain systems. Two main phytosociological types of meadows were distinguished within the classMolinio-Arrhenatheretea. The natural Siberian forest meadows were included in the orderCarici macrourae-Crepidetalia sibiricae comprising two alliances (Crepidion sibiricae, Aconito barbati-Vicion unijugae) and 7 associations. The anthropogenic types of dry meadows were included in the European-West Siberian orderArrhenatheretalia, comprising one alliance (Festucion pratensis) and 5 associations. DCA ordination revealed clear differences in the floristic composition of the higher units and in the diagnostic importance of the main ecological and phytosociological species groups.  相似文献   

3.
Long-term studies on the winter bird communities in the West Siberian Plain on a landscape basis allowed us to reveal the regional and seasonal patterns of their distribution. The highest proportion of species demonstrate forest-steppe and forest preference, a lower proportion demonstrate aquatic-semiaquatic preference, and the lowest proportion demonstrate tundra-forest-tundra preference. The preference zones do not change or extend in the winter period relative to summer postnesting period only in a small fraction of species; while the preference zones of most species were reduced or shifted. Commonly, the zonal borders of preferred habitats shifted southward to better climatic, feeding, and safety conditions. Only separate species with seasonally changing and specialized feeding demonstrated a northward shift of these borders.Translated from Izvestiya Akademii Nauk, Seriya Biologicheskaya, No. 2, 2005, pp. 201–207.Original Russian Text Copyright © 2005 by Vartapetov, Livanov, Tsybulin, Evsyukova.  相似文献   

4.
Using the Braun-Blanquet approach, 7 plant communities of forests and 3 communities of krummholz were distinguished on the Svyatoi Nos Peninsula on the eastern coast of Lake Baikal. Dominant species of these communities areAbies sibirica, Larix sibirica, Pinus sibirica, P. sylvestris, P. pumila andBetula divaricata. The data from Svyatoi Nos were combined with all the available data from the northern part of the Republic of Buryatia (289 relevés) and classified into 23 communities. These have been assigned to the following alliances:Aconito rubicundi-Abietion sibiricae—floodplain forests with tall forbs and the relict occurrence of a few nemoral species,Pino sibiricae-Laricion sibiricae—mesic forests with (sub-Atlantic) boreal species and abundant mosses,Vaccinio-Pinion pumilae—krummholz communities of NE Asian distribution,Cladonio stellaris-Laricion gmelinii—Larix gmelinii dominated open forests on permafrosts with NE Asian distribution, andHieracio umbellati-Pinion sylvestris—xeric forests with southern Siberian species. Phytogeographical affinities of these alliances are discussed and a system of high-ranked syntaxa (orders, classes) is proposed for the northern Buryatian forests and krummholz.  相似文献   

5.
The main trends in the territorial changes in winter bird communities and the environmental factors determining them were analyzed based on long-term counts in the East European and West Siberian plains. These trends are reduced to a decline in the winter avian complexes (in the number of species and individuals) in the north- and eastward directions and with a decrease in the degree of sheltering and feed reserves in the habitats associated with reduction in afforestation. The specific regional features of winter East European avian complexes are the larger number of species and individuals in the nemoral forest, forest-steppe, and steppe landscapes, and inland water bodies as compared with the West Siberian avian complexes, as well as an increased influence of the degree of development and agricultural transformation of landscapes.  相似文献   

6.
The paper reports results of analysis of spatial and typological inhomogeneity in small mammal communities of the West Siberian Plain and Altai as compared with that in amphibian, reptile, and bird communities.  相似文献   

7.
This work investigates the Polylepis-dominated forests in the high Andes of central and southern Bolivia, using both the Braun-Blanquet approach and multivariate analysis. These are among the highest altitude forest types in the world, and the region under study is a center of diversity for the genus, and is located at the confluence of four biogeographical provinces. Nine main plant communities were distinguished. Correspondence Analysis revealed a strong dependence of community composition primarily on biogeographic as well as on bioclimatic features. The greatest forest type diversity is found in the central part of the Cordillera Oriental in the Tropical pluviseasonal bioclimate, within a Supratropical thermotype and a Subhumid ombrotype.  相似文献   

8.
9.
In financially and human capacity poor countries, there is an important need to monitor the status of resource rich ecosystems in the face of growing extractive activities in simple and inexpensive ways. In this study we explore the potential of using birds as indicators of ecosystem change in the wetland systems of the North Rupununi, Guyana, where local communities rely heavily on wetland resources for their subsistence activities. This is done by (1) assessing what environmental factors determine bird communities at different spatial and temporal scales; and (2) identifying indicator groups and/or species for ecosystem status. We surveyed 31 wetland sites over 2 years, taking monthly recordings of both the environmental features of waterbodies using a modified version of the River Habitat Survey and bird species counts. Using multivariate analyses, we found that large-scale habitat type, namely forest and savanna, and waterbody type, namely pond or main river channel, were the main factors affecting bird species distribution. At the smaller scale, habitat features around the waterbody and seasonality become important factors. We were able to identify lists of bird species associated with different waterbody types, and we present this as a checklist for future monitoring. We hope these findings can be integrated into the adaptive management and sustainable livelihood goals of the local stakeholders through linking monitoring with tourism and local school curriculum activities.  相似文献   

10.
At the end of the first half of the 20th century, 61 species and subspecies of fish, including one invader (bleak Alburnus alburnus) and 17 species—endemics of Baikal—were reported for Siberia (Berg, 1933, 1949). At the present time, in rivers, lakes, and reservoirs of Siberia, 96 fish species and subspecies are described, of which 80 are aboriginal and 16 are invaders; 33 species are endemics of Baikal. Each landscapegeographic zone of Siberia has its specific ichthyofauna: in rivers and lakes of the south of Siberia, species of boreal piedmont complex dominate; in water bodies of the steppe, forest-steppe, taiga, and southern parts of the forest-steppe zone boreal plain dominates; in the zone of tundra, arctic freshwater dominates; and in Baikal, the most part (35) of species belongs to the Baikal autochtonous complex. Most researchers, as before, distinguish in Siberia two ichthyogeographic sites—West Siberian and East Siberian—that enter the Arctic Province of the Circumpolar subregion of the Holarctic region. Baikal is considered in the rank of the suboblast of the Holarctic.  相似文献   

11.
Invasive exotic species pose an important threat to biodiversity worldwide. However, there is little information on the effects that specific exotic bird species have on native biota. The House Sparrow is an excellent ecological model to evaluate the effect that an invasive exotic species has on native bird communities. Our study describes the relationship of the presence and abundance of House Sparrows with the structure, diversity, and composition of native bird communities in West Mexico. We used two approaches to compare House Sparrow invaded and non-invaded bird communities: (1) at a small geographic-scale that allowed us to evaluate shifts in avian communities with presence of the House Sparrow under similar environmental conditions; and (2) at the landscape-level to evaluate the effect of this species under a scenario of greater environmental heterogeneity. Results from both approaches show that areas invaded by House Sparrows have heavily-dominated avian communities with low species richness, while non-invaded areas exhibit highly-even and species-rich bird communities. Species turnover analysis indicates that the decrease in the number of bird species in House Sparrow invaded areas is caused by species loss, rather than a shift in species composition. Our results indicate that the invasion of an area by the House Sparrow, through synergistic interactions with human activities, determines the composition, structure, and diversity of native bird communities.  相似文献   

12.
应用定量方法研究草原群落分类的初步探讨   总被引:1,自引:1,他引:0       下载免费PDF全文
本文利用J.Moravec(1972)的方法,分析了松嫩平原南部草原群落组成的一致性与植物存在度的关系。结果表明,群落中植物存在度之间的关系有一定的规律,大多数是Ⅴ>Ⅳ⋛Ⅲ<Ⅱ<Ⅰ,而样方间的一致性主要取决于存在度大的植物种数及其存在度。根据上述关系计算了各组样方的一致性系数,最小值为39.6%,最大为72.3%。利用这些数值结合定性的分析,划分了11个群落类型,说明这是一种比较简易的群落分类的定量方法。  相似文献   

13.
We used an ordination approach to identify factors important to the organization of breeding bird communities in three floodplains: Cache River, Arkansas (AR), Iatt Creek, Louisiana (LA), and the Coosawhatchie River, South Carolina (SC), USA. We used 5-min point counts to sample birds in each study area each spring from 1995 to 1998, and measured ground-surface elevations and a suite of other habitat variables to investigate bird distributions and community characteristics in relation to important environmental gradients. In both AR and SC, the average number of Neotropical migrant species detected was lowest in semipermanently flooded Nyssa aquatica Linnaeus habitats and greatest in the highest elevation floodplain zone. Melanerpes carolinus Linnaeus, Protonotaria citrea Boddaert, Quiscalus quiscula Linnaeus, and other species were more abundant in N. aquatica habitats, whereas Wilsonia citrina Boddaert, Oporornis formosus Wilson, Vireo griseus Boddaert, and others were more abundant in drier floodplain zones. In LA, there were no significant differences in community metrics or bird species abundances among forest types. Canonical correspondence analyses revealed that structural development of understory vegetation was the most important factor affecting bird distributions in all three study areas; however, potential causes of these structural gradients differed. In AR and SC, differences in habitat structure were related to the hydrologic gradient, as indexed by ground-surface elevation. In LA, structural variations were related mainly to the frequency of canopy gaps. Thus, bird communities in all three areas appeared to be organized primarily in response to repeated localized disturbance. Our results suggest that regular disturbance due to flooding plays an important role in structuring breeding bird communities in floodplains subject to prolonged inundation, whereas other agents of disturbance (e.g., canopy gaps) may be more important in headwater systems subject to only short-duration flooding. Management for avian community integrity in these systems should strive to maintain forest zonation and natural disturbance regimes.  相似文献   

14.
Mal'kova MG 《Parazitologiia》2010,44(4):297-309
Analysis of long-term data on the fauna, landscape distribution, and structure of communities of the gamasid mites (Acari:Parasitiformes:Mesostigmata) connected with small mammals and their nests in the plain part of Western Siberia is carried out. By now, presence of 249 gamasid mite species is established in the territory under study, including 193 free-living and 56 parasitic species. Gamasid mites are represented by the maximal number of species on small mammals and in thers nests in northern forest-steppe (102 and 105 species respectively). Nine parasitic species from two ecological groups (epizoic and nidicolous) were found in all landscape zones of the West Siberian Plain, namely: 1) epizoic species Laelaps clethrionomydis Lange, 1955, Laelaps hilaris C. L. Koch, 1836, and Hyperlaelaps arvalis Zachvatkin, 1948 (obligatory non-exclusive hematophagous); 2) nidicolous species Androlaelaps casalis Berlese, 1887 (obligatory non-exclusive hematophagous), Eulaelaps stabularis C. L. Koch, 1836, Haemogamasus nidiformnes Bregetova, 1955 (facultative hematophagous), Haemnogamnasus ambulans Thorell, 1872 (obligatory non-exclusive hematophagous), Hirstionyssus isabellinus Oudemans, 1913, and Hirstionyssus eusoricis Bregetova, 1956 (obligatory exclusive hematophagous). Last three species demonstrate the mixed type of parasitism. The population of gamasid mites on small mammals is most specific in tundra, southern forest-steppe and steppe; the fauna of gamasid mites in nests is most specific in southern forest-steppe and steppe.  相似文献   

15.
Basing on materials collected in 1963, 1998, and 2009–2016, we describe subzonal changes in the population of small mammals in the Prealtai Plain, provide their classification, investigate the spatial–typological structure, and estimate the dependence of heterogeneity of communities on environmental factors. We compare the heterogeneity rate of the populations of West Siberian and Prealtai plains and mountain provinces of Altai.  相似文献   

16.
Aim Studies exploring the determinants of geographical gradients in the occurrence of species or their traits obtain data by: (1) overlaying species range maps; (2) mapping survey‐based species counts; or (3) superimposing models of individual species’ distributions. These data types have different spatial characteristics. We investigated whether these differences influence conclusions regarding postulated determinants of species richness patterns. Location Our study examined terrestrial bird diversity patterns in 13 nations of southern and eastern Africa, spanning temperate to tropical climates. Methods Four species richness maps were compiled based on range maps, field‐derived bird atlas data, logistic and autologistic distribution models. Ordinary and spatial regression models served to examine how well each of five hypotheses predicted patterns in each map. These hypotheses propose productivity, temperature, the heat–water balance, habitat heterogeneity and climatic stability as the predominant determinants of species richness. Results The four richness maps portrayed broadly similar geographical patterns but, due to the nature of underlying data types, exhibited marked differences in spatial autocorrelation structure. These differences in spatial structure emerged as important in determining which hypothesis appeared most capable of explaining each map's patterns. This was true even when regressions accounted for spurious effects of spatial autocorrelation. Each richness map, therefore, identified a different hypothesis as the most likely cause of broad‐scale gradients in species diversity. Main conclusions Because the ‘true’ spatial structure of species richness patterns remains elusive, firm conclusions regarding their underlying environmental drivers remain difficult. More broadly, our findings suggest that care should be taken to interpret putative determinants of large‐scale ecological gradients in light of the type and spatial characteristics of the underlying data. Indeed, closer scrutiny of these underlying data — here the distributions of individual species — and their environmental associations may offer important insights into the ultimate causes of observed broad‐scale patterns.  相似文献   

17.
Abstract. Up to now the syntaxonomy of the Fagus woods of the southern Balkans is far less known than that of beech communities in the northwestern part of the Balkan Peninsula and in central and western Europe. A set of 607 phytosociological relevés from southeastern Serbia, the Former Yugoslav Republic of Macedonia, and northern and central Greece was subjected to numerical classification and ordination. These results were used for a syntaxonomic revision of Fagus, Fagus‐Abies and Fagus‐Acer woodland communities of the southwestern Balkans. The Doronico columnae‐Fagenion (seven associations from Serbia, the F.Y.R.O.M., and high altitudes in northern Greece) and the Doronico orientalis‐Fagenion (four associations from northern and central Greece) were distinguished. The results of ordination by Canonical Variates Analysis (CVA) showed a very distinct phytogeographical pattern of differentiation between community types. The floristic composition of Fagus woods changes markedly along the north‐south gradient. The share of Subbalkan, Balkan, Submediterranean and Mediterranean species increases significantly towards the south, while the Central‐European, European, Euro‐Siberian, Euro‐Asiatic and Circumpolar species decrease in the same direction. The syntaxonomic differentiation of the Fagus woodlands and their classification into regional suballiances reflects this gradient. With the rise in altitude, the number of Balkan, Mediterranean, Submediterranean, European and Euro‐Asiatic species declines.  相似文献   

18.
Based on the analysis of materials collected for many years the dynamics of the moose’s habitat and population numbers in West Siberia is described. For the southeast of the West Siberian part of the habitat the cohabitation of mooses with the haplotypes of both European (A. a. alces L.) and East Siberian (A. a. pfizenmayeri Zukowski) subspecies is demonstrated on the basis of investigation of the structure of the mtDNA D-loop hypervariable domain. High nucleotide (p) and haplotypic (H) diversity substantially exceeding corresponding indices for the moose in the European part of Russia and the Urals has been revealed.  相似文献   

19.
Afforestation of open habitats is one of the principal land-use changes underway in Europe and elsewhere in the world at present, and it can have a considerable impact on local biodiversity. The sustainable expansion of global forest plantations requires an understanding of the factors that determine the ecological impacts of afforestation. This study set out to determine the importance of preceding land-use type in determining the outcomes of afforestation for bird communities. Paired comparisons of 5-year-old exotic conifer plantations and matching non-forested sites were studied in areas of low (peatland), intermediate (wet grassland) and high (improved grassland) management intensity. Afforestation resulted in an overall increase in total bird density in all three habitat types. The effects of forest planting on bird conservation were found to be positively related to prior management intensity at the site. The density of bird species of conservation concern increased in response to the planting of intensively managed grassland sites, but decreased in response to afforestation of peatlands and of grasslands under intermediate management intensity. This study shows that plantation forests can, in some contexts, offer opportunities for bird conservation, and the findings highlight the trade-offs that are an integral part of land-use change. Therefore, where afforestation planning includes consideration of its impact on bird communities, planting should take place predominantly on sites of low biodiversity value, such as agriculturally improved grasslands. Furthermore, the preservation of sites of high conservation value within areas of afforestation would confer advantages on bird communities.  相似文献   

20.
The proposed classification system reflects the difference between the three population systems: unbuilt land, built-up land, and aquatic–semiaquatic communities. Two superorder groups—north and median—further divided into types were recognized in each of the systems. Most types are divided into subtypes, classes, and subclasses (and sometimes genera of the population). The estimation of the power and generality of the influence of environmental factors (their variability correlates with heterogeneity of the avian population) has demonstrated that forestation of the territory is most significant in the first half of summer on the western Siberian Plain. The composition of the forest-forming species and zoning are less affected. The influence of moisture and hydration is 2–3 times less significant; mesorelief is 4–5 times less significant; and productivity (feeding capacity) and anthropogenic influence are 7–9 times less significant.  相似文献   

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