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1.
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   

2.
Soft sediments are often highly polluted as many of the toxic chemicals introduced into surface waters bind to settling particles. The resulting accumulation of pollutants in the sediments poses a risk for benthic communities. However, pollution induced changes in benthic communities have been difficult to determine when using macro-invertebrates as bioindicators, as these organisms are often absent in soft sediment. The present study therefore examined the ability of meiofaunal organisms, specifically, nematodes, to assess the ecological status of soft sediments. Over a 9-year period, nematode communities present in sediments collected from large rivers and lake Constance in Germany were studied. These sediments showed a large range of physico-chemical properties and anthropogenic contamination. After the degree of metal and organic contamination was translated into ecotoxicologically more relevant toxic units (TUs), multivariate methods were used to classify nematode taxa in species at risk (NemaSPEAR) or not at risk (NemaSPE(not)AR). This approach clearly distinguished the influence of sediment texture from that of the toxic potential of the samples and thus allowed classification of the nematode species according to their sensitivity to or tolerance of toxic stress. Two indices, expressing the proportion of species at risk within a sample (NemaSPEAR[%](metal), NemaSPEAR[%](organic)), were calculated from independent data sets obtained in field and experimental studies and showed good correlations with the toxic potential (field data) or chemical concentrations (microcosm data). NemaSPEAR[%] indices for metal and organic pollution were therefore judged to be suitable for assessing the impact of chemical contamination of freshwater soft sediments.  相似文献   

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4.
大型底栖动物快速生物评价方法可快速判断河流在人为活动影响下的生态状况,对河流健康评价研究和河流保护与管理具有重要的意义。基于太子河46个样点的大型底栖动物监测数据,探讨大型底栖动物生物监测工作组(Biological Monitoring Working Party,BMWP)指数的适用性。采用方差分析研究了BMWP指数对重要水环境参数的响应程度,研究结果表明BMWP指数随地表水水质级别的降低呈显著地下降趋势。利用回归分析研究了BMWP指数与其他生物指数、生境状况的回归关系,结果显示BMWP指数与底栖动物香农多样性指数(R2=0.74)、底栖动物完整性指数(R2=0.85)以及生境质量评估指数(R2=0.60)均呈显著线性回归关系(p0.01),表明BMWP指数可以有效指示与反映不同河段的生物状况及其栖息地质量。利用BMWP指数对采样点进行的河流健康评价结果显示太子河46个采样点中,极好和良好的采样点占45.7%,一般的样点占21.7%,差和极差的样点为32.6%。BMWP指数对河流生态状况指示灵敏,能够准确反映河流健康状况。同时,野外监测、物种鉴定和指数计算简便,是河流健康评价中表征能力较强的快速生物评价指数。  相似文献   

5.
Evaluating the biodiversity of previous and current species in a forest community is an important task. Some methodological researches and effective applications have been carried out widely in the temperate upland zone. However, they lack related researches in coastal shelter forests. This paper attempts to analyze them for Jiaonan coastal forest communities from the following three aspects, the relationship between plant biodiversity structure and its environment, the nexus between biodivers…  相似文献   

6.
New data on the present-day state of planktonic and benthic communities in the Sea of Azov were obtained during an expedition organized in 1997 and 1998. The analysis of their species composition and quantitative indices of biomass and abundance revealed two obvious tendencies in the structural dynamics of biocenoses. The first is directly produced by disturbances of the environment under anthropogenic impact, and the second reflects the effect of global natural factors.  相似文献   

7.
Abstract

Based on the research of the plots in coastal areas in Jiaonan city, Shandong Province, the indices of richness, evenness and diversity of different community types are analyzed. The results show that: The richness indices indicates that arbor layers are close to shrub layers, and both are lower than herbage layers; the ranges among communities vary a little except those of the arbor ones. Mostly the biodiversity indices reveal that herbage, the arbor, the shrub; Biodiversity of communities has great influences on microclimate to a certain extent and is under the control of regional environment.  相似文献   

8.
Traditional approaches to structural analysis of biotic communities, based on the data on species abundances, do not take into account phylogenetic relationships between these species. We propose a new approach to studying the scaling (scale dependence) of phylogenetic diversity by means of multifractal analysis in which the moments of phylogenetic diversity are used. The results of applying this approach to small mammal communities of Nizhny Novgorod region of the Volga Basin has shown that phylogenetic diversity scaling complies with the power law, which is indicative of the self-similarity of these communities. The multifractal spectra of phylogenetic diversity scaling markedly differ from the spectra of species diversity scaling, providing evidence that the proposed approach can provide novel information on the structure of biotic communities.  相似文献   

9.
Russian Journal of Ecology - This study has been carried out to determine water quality of Sang? Stream (West Anatolia, Turkey) and to compare the performance of indices used. Five biotic and...  相似文献   

10.
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   

11.
Specific structural features of the zooplankton community of Lake Imandra have been analyzed in areas polluted with wastewaters from the copper-nickel industry (Monche Bay) and apatite-nepheline industry (Belaya Bay) or heated waters from the Kola Nuclear Power Plant (Molochnaya Bay) and in a conditionally clean (background) area (the eastern and western parts of Babinskaya Imandra pool). The current ecological state of these communities has been assessed. The results contribute to knowledge about the responses of hydrobionts to pollution with different kinds of industrial wastewaters and the potential of using the zooplankton community as a reliable indicator for evaluating the state of aquatic ecosystems.  相似文献   

12.
以底栖动物为指示物种对长江流域水生态进行评价   总被引:5,自引:0,他引:5  
采用底栖动物作为指示物种对长江流域的水生态进行了调查研究和生态评价。在长江上游支流、中下游干流及沿江湖泊上选取36个代表性样点进行生态考察和底栖动物采样、鉴定和分析。采用Hilsenhoff生物指数和水化学分析对样点水质进行评价,对比分析了各样点底栖动物的结构组成及多样性。上游支流大部分样点水质清洁;中游干流及沿江湖泊水质受到轻度到中度污染;下游干流水质污染加重。底栖动物多样性在上游支流中最高,中游湖泊较高,干流中下游较低。总结得出了4种河床演变条件下的底栖动物群谱。上游支流河床稳定的河流底栖动物密度较大,物种丰富,多样性高;侵蚀下切的河流底栖动物密度、物种数和多样性较低;淤积抬升的河流底栖动物密度、物种数和多样性更低一些;河势散乱且河床运动剧烈的支流物种丰度和密度均很低甚至为零,生态条件差。  相似文献   

13.
A method for estimating the current state of plant communities based on the ecological amplitudes of constituent species is proposed. An original program, Fitoindikatsiya, has been developed to compute the indices of disturbance and homogeneity of plant communities from species ecological scale values. The current state of pine forests in the part of Novosibirsk oblast east of the Ob River has been analyzed; slightly, moderately, and severely disturbed zones have been distinguished.  相似文献   

14.
采用底栖动物作为指示物种对长江流域的水生态进行了调查研究和生态评价。在长江上游支流、中下游干流及沿江湖泊上选取36个代表性样点进行生态考察和底栖动物采样、鉴定和分析。采用Hilsenhoff生物指数和水化学分析对样点水质进行评价,对比分析了各样点底栖动物的结构组成及多样性。上游支流大部分样点水质清洁;中游干流及沿江湖泊水质受到轻度到中度污染;下游干流水质污染加重。底栖动物多样性在上游支流中最高,中游湖泊较高,干流中下游较低。总结得出了4种河床演变条件下的底栖动物群谱。上游支流河床稳定的河流底栖动物密度较大,物种丰富,多样性高;侵蚀下切的河流底栖动物密度、物种数和多样性较低;淤积抬升的河流底栖动物密度、物种数和多样性更低一些;河势散乱且河床运动剧烈的支流物种丰度和密度均很低甚至为零,生态条件差。  相似文献   

15.
The body size structure of carabid communities has been analyzed based on the 2009 and 2013 collections (with the use of pitfall traps) performed at 10 sites of a spruce–fir forest along the gradient of pollution with emissions from the Middle Ural Copper Smelter. A reduction in the unweighted mean body size of carabid individuals has been shown, as well as the heterogeneity of body sizes in the community (Gini coefficient) of the extremely polluted territory. It has been revealed that the weighted mean body size of individuals and the Lorentz asymmetry coefficient are not dependent on the level of pollution. Differences between the communities of carabids in the background and polluted territories are associated with the smaller number of large-sized species, while the similarity is explained by the dominance of medium- and small-sized species at all sites. The high interannual variability has been observed in the ratio of size groups of the analyzed communities at the background and moderate levels of pollution.  相似文献   

16.
Communities of benthic macroinvertebrates in drainless Lake Chany, the largest lake in Western Siberia, have been analyzed to estimate the effects of basic abiotic ecological factors (hydrophysical and hydrochemical parameters of water and the type of bottom ground) on their composition, structure, and dynamics. It has been shown that the level of development of these communities depends mainly on the water regime of the lake and also on the type of bottom ground, lake depth, and water mineral content.  相似文献   

17.
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   

18.
The saturation of herbaceous communities with adventive species in the Northern Caucasus has been estimated using as an indicator the number of such species in 0.5-m2 plots. Among factors accounting for variation in the test parameter, consideration has been given to the coverage of the herbaceous layer, the species richness of communities (in 0.5-m2 plots), and the numbers of adventive and indigenous species (in 15-m2 plots). The field data have been processes by methods of ordinary and multivariate regression analysis. The results show that variation in saturation with adventive species between small areas of herbaceous communities largely depends on the number of such species in larger areas, their species-holding capacity, and the level of completeness of communities.  相似文献   

19.
A screening ecological risk assessment (ERA) was conducted for the first time in the Mediterranean basin in order to assess the toxicity posed to the benthic community by PCBs, DDTs and HCB in marine sediments. The characterization of the exposure was conducted by means of an extensive literature survey, generating a database with more than 2000 samples. The effects were assessed by the adoption of guidelines previously developed in the literature, because ecotoxicological information about persistent organic pollutants (POPs) in the Mediterranean sediments was lacking. Existing sediment quality guidelines (SQGs) for the target pollutants were compiled and consensus values were calculated for three different categories of toxicity, namely threshold effect concentration (TEC), probable effect concentration (PEC) and extreme effect concentration (EEC). The combination of exposure and effects characterization enabled the identification of some areas of concern in the vicinity of industrial and urban locations and in the mouths of the main Mediterranean rivers. Beyond the Mediterranean continental shelf, the level of toxicity for the benthic community was generally low. The evaluation of the toxicity induced by the mixture of the target pollutants spotted the importance of DDT contamination in the Mediterranean sediments, despite the fact that main inputs to the sea have been significantly reduced during the last decades.  相似文献   

20.
Transformation of meadow communities under the impact of hay harvesting and livestock grazing has been studied in the floodplains of the Vychegda and Pechora rivers. Changes in the floristic composition, structure, and productivity of meadows have been evaluated using synanthropization and adventization indices. On this basis, meadow phytocenoses at three different stages of pasture digression have been distinguished.  相似文献   

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