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Structural characteristics of benthic macroinvertebrate communities in mountain watercourses of different sizes have been studied in the Upper Ob basin. It has been found that species richness, diversity of zoobenthos, and most biotic indices in the background areas increase in the series from the smallest watercourses to large rivers. On the contrary, the values of the above parameters in areas polluted with mercury has proved to decrease, thereby indicating a significant transformation of the benthic communities. Approaches are proposed to select reference indices for assessing the ecological state of watercourses in the basin with regard to the size of the river, the structure of benthic communities, and variability of biotic indices along the background cross sections.  相似文献   

3.
The results of long-term studies on the fauna and ecology of murine rodents inhabiting the mountain forest belt of southern Central Siberia are considered. A comparative analysis of the composition and organization of rodent communities has been performed in 15 key plots located within three geographic-climatic facies: perhumid, humid, and semihumid. The species composition, dominance structure, and total abundance of these communities in each facies have significant distinctive features, despite the generally high similarity of the communities within the forest belt. Information indices have been used to determine parameters of the diversity and evenness of communities, which reflect their state and degree of resistance to various factors.  相似文献   

4.
The ranges, spectra of habitat types, and food spectra of artiodactyls in the Far East have been studied. It has been supposed that the overlap of ranges and habitat-type spectra should decrease with an increase in the overlap of food spectra. However, all the three similarity indices have proved to be positively correlated with each other, suggesting that, on the regional scale, the negative role of trophic competition in artiodactyl communities is insignificant, probably because of their low abundance. Conversely, the similarity of food spectra may be regarded as a factor accounting for the overlap of ranges and habitat spectra and, on a large-region scale, for the maintenance of high species diversity.  相似文献   

5.
On the basis of syntaxonomy of primary forests in the Southern Ural region, an analysis of trends in the formation of their species diversity has been performed in regard to heat supply, soil moisture, and general soil richness. The roles of environmental factors have been estimated using Landolt’s scales. The results have shown that communities of forest classes Querco-Fagetea, Brachypodio-Betuletea, and Vaccinio-Piceetea differ in the trends of changes in species richness along gradients of the above factors. In communities of all these classes, species richness depends primarily on heat supply, with soil richness being the second most important factor.  相似文献   

6.
Parameters of species and typological diversity of forest vegetation have been evaluated on macroslopes descending to Lake Imandra in the vicinity of the Severonickel Mining and Smelting Complex (SMSC) (Murmansk oblast). It has been shown that these parameters change upon an increase in the pollution level, with the pattern of changes in northern taiga forests differing from that in krummholz stands. The species richness and typological diversity of forest communities increase in the middle zone of the pollution gradient, compared to those in the krummholz belt occupying the upper parts of the slopes. Species saturation in all types of communities on landscape transects consistently decreases along the pollution gradient. In general, changes in parameters of diversity provide evidence for strong digression of plant communities in the vicinity of the SMSC.  相似文献   

7.
The structure of benthic communities was studied in the continuum of the model mountain river Komarovka, which flows in the conifer-broadleaf forest subzone in the southwest of the Silkhote-Alin Mountain Range (Primorye, Russia). The lowest species diversity of phyto- and zoobenthos was recorded in the upper reaches of the river, in a heterotrophic area; the highest species diversity, in the central part of autotrophic area. At the same time, the Shannon index for algal communities had the highest values in the heterotrophic area, while that for bottom invertebrate communities, within the autotrophic area. Thus, the increase in invertebrate species diversity in the river continuum was accompanied by complication of the structure of zoobenthos, while the increase in the taxonomic diversity of phytobenthos took place against the background of increasing dominance of a few algal species.  相似文献   

8.
The results of three-year studies on Collembola communities in spruce-fir forests along the gradient of pollution with emissions from the Middle Ural Copper Smelter (Revda, Sverdlovsk oblast) are presented. They show that the species and ecological structure of these communities change abruptly in the impact zone (1 km from the source of emissions), compared to the background zone (30 km from the source), which involves a decrease in the abundance and diversity of Collembola. Their total abundance and species richness in the zone of intermediate disturbance (7 and 4 km) are considerably higher than in the background zone, and the species structure of communities is characterized by superdominance. Four species groups differing in sensitivity to pollution are distinguished. Preference for zones with different pollution levels in closely related species is regarded as a case of ecological vicariation.  相似文献   

9.
Comparative analysis of the structure of small mammal communities has been performed in two European cities located in different biomes: Chisinau (2008?C2009) and Yaroslavl (1994?C2002). The parameters studied included abundance, species composition, similarity and difference of faunas, species diversity, and proportions of groups differing in predisposition to synanthropy. It has been found that the structure of small mammal communities in these cities depends on specific physiographic conditions of the surrounding areas and on the distinctive features of the cities themselves (their structure, age, etc.). The similarity between the faunas is accounted for by the common ecological patterns of fauna formation in the biota of urban cenoses.  相似文献   

10.
The structure of hibernating bat communities has been studied in eight artificial caves of Samarskaya Luka differing in size and layout. Three types of the relative abundance distribution (RAD) of species in these communities have been revealed. Conditions for hibernation are most favorable in large caves with a stable microclimate, where the abundance of bats is high, the Shannon index has the peak values, and variation in the index of species evenness is the lowest. In such caves, RAD fits the broken-stick and log-series models. Variation in diversity indices reaches the highest level in shallow adits with a changeable microclimate, where RAD fits the geometric series model. The abundance, diversity, and structure of communities depend mainly on cave size and the presence of absence of drafts and, to a lesser extent, on ambient temperature, availability of microshelters, and the type of landscape surrounding the cave. Anthropogenic factors have a weak effect only on the abundance of individual species (M. nattereri, M. daubentonii, M. dasycneme, and E. nilssonii) but not on the overall diversity of bat communities.  相似文献   

11.
Russian Journal of Ecology - The temporal dynamics of species diversity and projective coverage of herbaceous communities formed on fallows and dumps was studied. Annual studies of these...  相似文献   

12.
基于2013~2015年、2017~2018年长江中游监利江段的鱼类资源监测数据,采用多样性指数和多元统计方法分析该江段的鱼类群落结构特征。研究表明:5年共监测到鱼类68种,隶属于6目13科,其中鲤形目共46种;2018年监测的鱼类种类数要多于其他年份。各年份的均匀度指数值相差不大,2018年Shannon Wiener指数值和Margalef丰富度指数值要大于前面4个年份,优势度指数值有一定波动,但值均偏低。ABC曲线及W统计表明2013年和2014年鱼类群落结构受到了人类活动的严重扰动,而2015、2017和2018年受到人类活动的扰动程度不大。聚类分析和非度量多维尺度分析显示鱼类群落可以分为三组,但相似性分析表示三组间无明显差异。  相似文献   

13.
湖泊鱼类养殖是非常重要的一种水产养殖方式,然而不同鱼类养殖和管理方式对湖泊浮游植物群落的影响及其季节动态尚不明确。2016年3月~2017年1月按季度调研了长江中游9个湖泊的浮游植物,所研究湖泊包括以下4组:水库极低密度放养组(SR组)、禁养组(SN组)、低密度养殖组(SL组)和高密度养殖组(SH组)。研究表明:4组湖泊共鉴定出浮游植物8门110属,以绿藻、硅藻和蓝藻为主。水库组优势种季节演替明显,其余3组均存在比较稳定的优势种,其中禁养组与高密度养殖组为平裂藻,低密度养殖组为假鱼腥藻。4组湖泊浮游植物丰度的季节变化规律不同,依赖于蓝藻优势度的变化。根据浮游植物多样性指数判断,4组湖泊水体污染状态(即营养状态)存在季节差异,Shannon Wiener指数与Pielou指数对水体污染状态的评价结果较为一致。对4组湖泊四季的浮游植物的数量进行了层序聚类分析与非度量多维尺度分析(NMDS),结果显示水库组单独为一类;禁养组与高密度养殖组除了夏季外,其余季节均为一类。不同鱼类养殖方式对湖泊浮游植物群落的结构及季节动态产生了一定的影响,然而短期的禁养并没有明显改变湖泊浮游植物群落。  相似文献   

14.
为系统阐明长湖鱼类群落结构特征,2014年3~11月对长湖鱼类群落结构的空间差异和季节动态进行了较为全面的调查。结果表明,长湖共调查到鱼类43种,隶属于7目14科37属,主要为湖泊定居型鱼类;大湖区和海子湖区鱼类优势种组成虽存在一定的差异,但鲫、鰐、鲤和达氏鲌为两个湖区的共同优势种;长湖鱼类群落的Margalef丰富度指数、Shannon-Wiener多样性指数和Pielou均匀度指数分别为0.53~2.30、0.52~2.02和0.24~0.66,除丰富度指数外,均表现为5月或8月相对较高;聚类和MDS排序分析结果表明长湖鱼类群落分为两大类群,呈现显著的时空异质性;ABC曲线显示长湖优势鱼类以小型鱼类或大型鱼类的幼体为主,且已受到不同程度的干扰。针对长湖鱼类资源已出现衰退,建议在拆除围网/拦网养殖、取缔有害渔具的同时,考虑增殖放流、栽种水生植物等措施来达到长湖鱼类资源保护和可持续利用的目的。  相似文献   

15.
Radioactive contamination affects soil organisms and causes profound structural rearrangements in soil zoocenoses, which are manifested in the decreased species diversity of invertebrate communities and low relative abundance of large soil invertebrates. However, these communities gradually recover their initial structure. The soil biota near the epicenter of an underground nuclear explosion performed 30 years ago in Perm oblast has been studied to reveal specific structural features of the soil macro- and microfauna. Its structural diversity is considered with regard to such components as species (taxonomic) composition, the structure of dominance, and the ratio of ecological and trophic groups.__________Translated from Ekologiya, No. 3, 2005, pp. 171–179.Original Russian Text Copyright © 2005 by Kolesnikova, Taskaeva, Krivolutskii, Taskaev.  相似文献   

16.
New data are presented on unique refugia accounting for the high floristic diversity of dark conifer forests of the Northern Urals, which have some of the highest parameters of species saturation among boreal forests of northern Eurasia. Based on the results of analysis, the most significant biological factors have been revealed and their influence on boreal tall-herb and background plant communities has been evaluated.  相似文献   

17.
The contribution of synanthropization to the anthropogenic evolution of vegetation has been analyzed by assessing its level in approximately 260 associations and communities of 31 vegetation classes in the Republic of Bashkortostan. The results show that this level is high in communities of synanthropic classes Secalietea, Chenopodietea, Artemisietea vulgaris, and Robinietea. Synanthropization of communities under the effect of human activities is also characteristic of many classes of natural vegetation, especially those of meadows, floodplain forests, and ravine-gully systems. Some communities are protected from synanthropization due to the existence of abiotic or biotic barriers to the expansion of synanthropic species (communities of high-mountain areas and zonal forests, many aquatic communities, and mountain meadows and steppes).  相似文献   

18.
Specific ecological features of ground beetles inhabiting city parks and suburban areas were studied in the large industrial city of Nizhnii Tagil (Sverdlovsk oblast). Carabid cenoses of city parks retained considerable species diversity but proved to be strongly dominated by a limited number of species. An analysis of their state before and after recreational impact revealed changes in the species composition of communities, the set of dominant species, the degrees of their dominance, and the ratio between classes of life forms. The results show that the stronger the recreational impact, the more significant the decrease in the species diversity of the carabid community.  相似文献   

19.

The ideas of the evolutionary ecology of the 20th century and its modern conceptual space are considered with regard to new knowledge of the contents of population and evolutionary synecology. The article proposes (1) a population cenotic approach to analyzing the covariation of cenopopulations of sympatric species and taxocenes in space and historical time; (2) an approach to assessing the intragroup morphological disparity in cenopopulations of sympatric species and taxocenes as a measure of morphogenetic stability. Consideration is given to experimental evolutionary ecology as a particular methodological area. Prospects for the formation of evolutionary ecology as an interdisciplinary applied science are discussed in view of the necessity of predicting regional biocenotic crises and rapid coevolutionary changes in biotic communities in a technogenic environment against the background of predicted unfavorable trends of climate changes.

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20.
The abundance, structure, and distribution of oribatid communities in high-mountain pine forest biotopes of the Eastern Caucasus are described in dependence on elevation above sea level. The oribatid fauna of high-mountain pine forests proved to be characterized by high abundance, an assortment of dominants, and species richness. It was shown that, as the elevation increases, specific dominants typical of particular altitudinal zones appear in communities, and changes in the mass species occur. These species are stable in terms of their long-term dynamics, and zonal groups (communities) demonstrate a high species diversity.  相似文献   

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