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1.
Similarity coefficients were quantified for the ecosystems of the West Siberian Plain on the basis of the air-dry masses of dominant and subdominant plant species in five life forms (mosses, lichens, grasses, dwarf shrubs, shrubs, and trees) indicated in the formation ranges of the phytogeographic map of the West Siberian Plain. The resultant matrix was studied with cluster analysis and two classifications were made: one averaged over the formation ranges and the other over groups of the formation ranges. Expected informativity of the proposed classifications expressed in explained variance was 11–16% higher than that of the vegetation-based division used in the original phytogeographic map.  相似文献   

2.
The author has surveyed the diversity of lichen biota of West Siberia and distribution of lichens over its two geographic parts: the West Siberian Plain and the mountain frame in the south of West Siberia. The diversity of lichen biota in entire West Siberia is currently estimated at 1845 species in 325 genera and 95 families. The diversity of the West Siberian Plain is estimated at 1421 species in 271 genera and 86 families, and that of the southern mountains of West Siberia, at 1682 species in 312 genera and 94 families.  相似文献   

3.
The authors discuss the indicator value of taxonomic structure, abundance, and biomass of phytoplankton and use of the indicators to characterize water quality by example of the Karasuk River, West Siberian Plain.  相似文献   

4.
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   

5.
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   

6.
Distribution of black grouse and hazel grouse was evaluated on the basis of the results of bird counts from July 16 to August 31, 1959–2005 over all natural geographical zones and subzones of West Siberia (with fractioning down to the type of landscape tract). Data averaging over groups of vegetation map units (dynamic series) and other specific averaging procedures revealed that black grouse is common in northern-, middle-, and southern-taiga bogs; in subtaiga pine forests; in grassy bogs combined with halophytic meadows within the boundaries of subtaiga forests and the northern forest-steppe; and in agricultural lands in the northern forest-steppe. Hazel grouse is numerous in southern-taiga and dark coniferous middle-taiga forests and their derivatives. The number of hazel grouse individuals in these habitats is larger than in other lands. In general, over the subzones, both black grouse and hazel grouse are most numerous in the middle and southern taiga and in subtaiga forests. To the north and to the south of these subzones, the abundance of these species decreases. They were not encountered in tundras and some open forest-steppe and steppe habitats.  相似文献   

7.
Seasonal dynamics and changes in the general condition of the Italian locust population in the southeast of the West Siberian Plain that were observed throughout the 20th century are characterized in this paper. It was demonstrated that during the last outbreaks of mass reproduction of this species, dominant were individuals transitional from typical gregarious to typical solitary ones. A complicated undulating picture of long-term spatial redistribution of maximum and minimum densities of the Italian locust is detected for the first time, and drastic dynamic differences between neighboring groups of its local populations are shown. The regularities found are in discrepancy with the traditionally accepted unidirectional character of long-term changes in the species numbers within one physiographic region.  相似文献   

8.
Results of classification of terrestrial ecosystems using an average similarity matrix are reported for the West Siberian Plain. Initial indices are first calculated separately for four components of an ecosystem. These components (blocks) include the underground block (soil humus, mortmass, and underground phytomass), above-ground vegetation, and invertebrates and vertebrates. Mismatch of boundaries in separate blocks of ecosystems and in comparison with the inhomogeneity of ecosystems in general was demonstrated. These differences are observed in both the typological and typological-chorological analysis. The indicated features of spatial succession within the blocks generate continuity of ecosystems and the conventional character of all the classifications and drawn boundaries.  相似文献   

9.
The results of studies in factor zoogeography performed by the Laboratory of Zoological Monitoring (Institute of Systematics and Ecology of Animals SB RAS) over 50 years are briefly reported. The review deals with the distribution and abundance of terrestrial animals, changes in the shape of their assemblages in the West Siberian Plain, Altai, and adjacent areas, and faunal zonation of Northern Eurasia.  相似文献   

10.
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   

11.
Abstract: Since 1980, northern bobwhite (Colinus virginianus) range-wide populations declined 3.9% annually. Within the West Gulf Coastal Plain Bird Conservation Region in the south-central United States, populations of this quail species have declined 6.8% annually. These declines sparked calls for land use change and prompted implementation of various conservation practices. However, to effectively reverse these declines and restore northern bobwhite to their former population levels, habitat conservation and management efforts must target establishment and maintenance of sustainable populations. To provide guidance for conservation and restoration of habitat capable of supporting sustainable northern bobwhite populations in the West Gulf Coastal Plain, we modeled their spatial distribution using landscape characteristics derived from 1992 National Land Cover Data and bird detections, from 1990 to 1994, along 10-stop Breeding Bird Survey route segments. Four landscape metrics influenced detections of northern bobwhite: detections were greater in areas with more grassland and increased aggregation of agricultural lands, but detections were reduced in areas with increased density of land cover edge and grassland edge. Using these landscape metrics, we projected the abundance and spatial distribution of northern bobwhite populations across the entire West Gulf Coastal Plain. Predicted populations closely approximated abundance estimates from a different cadre of concurrently collected data but model predictions did not accurately reflect bobwhite detections along species-specific call-count routes in Arkansas and Louisiana. Using similar methods, we also projected northern bobwhite population distribution circa 1980 based on Land Use Land Cover data and bird survey data from 1976 to 1984. We compared our 1980 spatial projections with our spatial estimate of 1992 populations to identify areas of population change. Additionally, we used our projection of the spatial distribution and abundance of bobwhite to predict areas of population sustainability. Our projections of population change and sustainability provide guidance for targeting habitat conservation and rehabilitation efforts for restoration of northern bobwhite populations in the West Gulf Coastal Plain.  相似文献   

12.
The densities of two benthic fishes, the Siberian stone loach (Noemacheilus barbatulus) and the wrinklehead sculpin (Cottus nozawae), and the biomass of their food resources (i.e., periphyton and benthic invertebrates) were compared between forest and grassland streams in northern Hokkaido, Japan, to examine whether riparian deforestation had positive effects on the benthic fishes via enhancement of food availability. The comparisons indicated that riparian vegetation had little influence on periphyton, invertebrates, or fishes. Regression analysis indicated that spatial variations in loach and sculpin densities were explained more by substrate heterogeneity, competitor abundance, or both, rather than by food abundance. However, when the two species were combined as benthic insectivores, a strong correlation was found between total benthic fish density and invertebrate biomass. Our results suggest that, although total benthic fish abundance was food limited, riparian vegetation had no positive effects via food availability on the benthic fishes in our streams.  相似文献   

13.
The results of a 20-year study of the spatial distribution of clavarioid mycobiota in the West Siberian Plain (WSP) are discussed. The species structure has been studied on two scales: regional (an area of 100000 km2) and local (100 km2). In the studied area, 121 species of clavarioid fungi are found. The patterns of spatial variability of species diversity on the plain are revealed. On the regional scale, the maximum species richness of fungi is observed in hemiboreal forests (104 species); on the local scale it ranges from the middle boreal to hemiboreal (54.3–54.5 species). With the increasing pessimality of the hydrothermal regime, the number of species decreases sharply on both scales in the direction of the tundra and steppes. The study of the distribution of diversity among the localities reveals changes not only along the latitudinal gradient, but also in the longitude sectors: in the forest zone, the richest localities are located on the western and eastern edges of the plain, while in the extensive marshy areas in the center the number of species is lower (p < 0.05). A map of the spatial distribution of species diversity for the local scale is constructed. The correspondence of the spatial distribution of the studied fungi group to a global latitudinal gradient is discussed. The main abiotic factors forming a variety of the studied group of fungi in the region are revealed.  相似文献   

14.
Differentiation of the vertebrate communities almost coincides with the differentiation of ecosystems in vegetation at the type level, as judged by formalized classifications of various blocks of ecosystems of West Siberia by geobotanical map units, and it differs significantly from that in the underground component due to the greater effect of waterlogging on the latter. In invertebrate communities, significant differences are observed in the boreal-subboreal part, where waterlogging is more significant and greater similarity is found among middle and southern-taiga communities than among subtaiga-steppe ones. Over the groups of map units, the heterogeneity of the vertebrate communities differs from that in all the examined blocks of ecosystems in greater differentiation in the tundra zone. In the pretundra northern taiga subzones and from the middle taiga to the steppe zone, the heterogeneity of vertebrate communities is somewhat lower than that of vegetation, and especially in the underground block of ecosystems. However, these differences relate only to the hierarchy of the division, and often occur at the level of taxa of the rank of subtype or class. All these data indicate the relative independence of changes in the distinguished blocks of ecosystems, which gives rise to noncoincidence of the boundaries and sizes of taxa within them, as well as the continuality of the ecosystems as a whole. A significant difference is observed between the traditional geobotanical and typological-chorological zones of terrestrial vertebrate communities.  相似文献   

15.
 本文在对松嫩平原的草原植被作了全面调查,记录了760多个样方以及对生境,特别是土壤的一些主要因子做了分析的基础上,采用植物与生境和定性与定量相结合的方法;确定以植物种类组成(特别是生态种组)、群落相似性的数量指标和动态特征为依据的分类原则。划分了4个群目、12个群属和40个群丛,建立了三级的分类系统,并阐明各等级分类单位的特征,揭示了松嫩平原草原植物的组合规律及其与环境的关系。不同等级分类单位的相似和差异,体现了分类系统是一个有机的整体和调查区植被的连续性和间断性.此外,分类系统的高级分类单位与立地类型的对应关系,为草原的经营管理提供了依据。  相似文献   

16.
1. Small cages (294cm2) containing unglazed clay quarry tiles were used to investigate the influence of periphytic algae on macroinvertebrate abundance in a Hong Kong stream. Algal biomass was manipulated by shading cages with plastic sheets. Individual cages were assigned to one of three treatment groups: unshaded, shaded and deeply shaded. Invertebrate densities and algal biomass within cages were monitored after 23, 37 and 65 days. 2. Multiple-regression analysis revealed that algal biomass, invertebrate morphospecies richness and total abundance declined with greater shading intensity. The responses of individual invertebrate taxa varied: some (especially Trichoptera) were unaffected by shading, whereas grazers (Baetidae, Psephenidae and Elmidae) declined as shading increased. 3. Significant regressions of the densities of individual taxa upon algal and detrital standing stocks in cages had positive slopes, but algal biomass increased during the study while detrital standing stocks declined. Abundance of invertebrates declined or remained rather stable over time. Density increases resulting from a positive association with algae were apparently offset by declines in abundance correlated with reductions in detritus. 4. Declines in algal biomass were associated with greater shading to which animals may respond directly. To uncouple the link between scarcity of algae and reduction of light intensity, the plastic covers on two groups of cages (deeply shaded and unshaded) which had been placed in the stream for 28 days were reversed so that cages which had been shaded became unshaded and vice versa. The cages were recovered on day 33, Only Coleoptera demonstrated a positive association with atgae inside cages; no relationship between population densities and algal biomass or light intensity was apparent for other taxa. However, the design may have been confounded by deposition of sediment in the cages (due to declining stream discharge) which reduced population densities of colonizers. 5. This study documents changes in invertebrate abundance and morphospecies richness in response periphyton and detritus standing stocks within patches. Summation of such responses may account for observed variations in benthic communities among Hong Kong streams which differ in the extent of shading by riparian vegetation.  相似文献   

17.
An analysis of information on the groundwater dynamics, frequency of fire events, and postfire progressive-age stages of vegetation in the swamp-forest ecosystems of the southern taiga and forest-steppe zone of the West Siberian Plain has shown that fire events are a permanent factor that controls the scales and dynamics of the forest and swamp formation processes under these specific conditions in the modern era. The greatest influence on the dynamics of ecosystems is exerted by the frequency of fires. The scope and depth of the transformation of swamp ecosystems affected by the pyrogenic factor are due to their environmental regimes and have their own properties in different landscapes.  相似文献   

18.
1. We compared the size distribution of aquatic invertebrates in two prairie wetlands, one supporting a population of fathead minnows and the other fishless. Both wetlands were sampled in three depth zones on three dates, allowing assessment of temporal and spatial variation.
2. We determined biomass of aquatic invertebrates in 17 log2 size classes, and used these data to develop normalized size spectra. We also coupled size distributions with an allometric model to estimate relative production at the community level.
3. The composition of the invertebrate communities differed greatly between sites, and invertebrate biomass was higher in nearly all size classes in the fishless wetland. Intercepts of normalized size spectra were significantly different between wetlands, but slopes generally were not, indicating differences in standing-stock biomass but similar size structures between the two invertebrate communities. Higher standing-stock biomass in the fishless wetland resulted in higher relative production per unit area, but similar size distributions resulted in similar mass-specific production (P/B) between wetlands.
4. Our results indicate that invertebrate communities in prairie wetlands may have relatively consistent size structures in spite of large differences in community composition and standing-stock biomass. We hypothesize that the observed differences are because of predation by the minnow population and/or differences in the macrophyte communities between the two sites. However, the relative importance of macrophytes and fish predation in structuring invertebrate communities in prairie wetlands is poorly known.  相似文献   

19.
Habitat structure is one of the fundamental factors determining the distribution of organisms at all spatial scales, and vegetation is of primary importance in shaping the structural environment for invertebrates in many systems. In the majority of biotopes, invertebrates live within vegetation stands of mixed species composition, making estimates of structural complexity difficult to obtain. Here we use fractal indices to describe the structural complexity of mixed stands of aquatic macrophytes, and these are employed to examine the effects of habitat complexity on the composition of free-living invertebrate assemblages that utilise the habitat in three dimensions. Macrophytes and associated invertebrates were sampled from shallow ponds in southwest England, and rapid digital image analysis was used to quantify the fractal complexity of all plant species recorded, allowing the complexity of vegetation stands to be reconstructed based on their species composition. Fractal indices were found to be significantly related to both invertebrate biomass–body size scaling and overall invertebrate biomass; more complex stands of macrophytes contained a greater number of small animals. Habitat complexity was unrelated to invertebrate taxon richness and macrophyte surface area and species richness were not correlated with any of the invertebrate community parameters. The biomass–body size scaling relationship of lentic macroinvertebrates matched those predicted by models incorporating both allometric scaling of resource use and the fractal dimension of a habitat, suggesting that both habitat fractal complexity and allometry may control density–body size scaling in lentic macroinvertebrate communities.  相似文献   

20.
Similarity was quantified for the ecosystems of the West Siberian Plain based on the masses of plant cover, dead organic matter, and underground organic matter (including soil humus) and the resultant matrix was subjected to cluster analysis. The results showed that the differentiation in the vegetation was nearly equally attributable to zonal gradients of thermal and moisture conditions (waterlogging), while the differentiation in the underground part of the ecosystems was predominantly under control of waterlogging. Intratypical differences in the underground part were due to zonal-subzonal heterogeneity in the gradients of thermal and moisture conditions, composition of vegetation, and flooding during snow-melt period. Such division did not entirely agree with subzonal division. The ecosystems were rather aggregated on the basis of the three abovementioned characteristics, with flooding and forest-forming species being the same.  相似文献   

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