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1.
Ordination methods were applied to the identification of structural units in the phytoplankton community. The groups of phytoplanktonic species identified by the time gradient and the method of cluster analysis of species lists were compared. The structural complexity of the phytoplankton community was evaluated using the index of cenotic significance (ICS) and derivative calculation coefficients. A high degree of similarity in the structure of dominance between the zooplanktonic and phytoplanktonic communities of the water body was revealed.  相似文献   

2.
General trends in simplification of the structure and composition of forest communities in the zone of impact from the metallurgical industry are revealed. The load of toxicants is estimated from the concentrations of heavy metals in the snow and soil. The method is proposed for assessing biological damage on the basis of the main characteristics of phytocenosis, such as its species diversity and the cenotic significance of its structural components. The resultant integrated index of phytocenosis preservation (IIP p) characterizes the degree of biological damage, and its value depends on the load of toxicants and resistance of plant communities characteristic of different natural zones.  相似文献   

3.
It has been shown that endomycorrhizas are found in the majority of herbaceous plants, but their adaptive significance is ambiguous. As a rule, the degree of development of plants and their parts, cenotic status of the species, and species diversity of plant community manifest no definitely positive correlation with the level of mycorrhiza development on root systems. Interactions between the partners in most cases can be classified as indifferent or negative.  相似文献   

4.
为了解长江荆江段浮游生物的群落结构特征以及其与环境因子之间的关系,于2017年3、6、9和12月对荆江7个采样断面的左右岸共14个采样点的浮游生物群落结构及水文、水质参数进行了调查。结果表明:荆江采集到浮游植物7门67属135种(含变种),以硅藻门(51.85%)和绿藻门(25.19%)为主。浮游植物的丰度均值为73.16×10 4 cells./L,生物量均值为0.87 mg/L,上荆江各采样断面间浮游植物丰度和生物量变化不明显,下荆江浮游植物的丰度和生物量表现从上游到下游逐渐增高的趋势。优势种为硅藻门的颗粒沟链藻和梅尼小环藻。Margalef 丰富度指数是0.83,Pielou均匀度指数是0.80和Shannon-Wiener多样性指数是1.90,下荆江的丰富度指数和多样性指数大于上荆江,说明上荆江比下荆江污染严重。典范对应分析溶氧、温度、氨氮是影响浮游植物群落结构的主要因素。浮游动物48属81种,其中轮虫最多(37.04%),其次是原生动物(25.93%)和枝角类(23.46%)。浮游动物丰度均值为6.32 ind./L,生物量均值为88×10-3 mg/L,上荆江浮游动物丰度和生物量低于下荆江。浮游动物优势种为冠砂壳虫、桡足类无节幼体和剑水蚤一种。Margalef 丰富度指数是5.2,Pielou均匀度指数是0.84和Shannon-Wiener多样性指数是1.32,下荆江的丰富度指数、均匀度指数和多样性指数均大于上荆江,说明上荆江比下荆江污染严重。冗余分析显示温度、溶氧和氨氮是影响浮游动物群落结构的主要因素。  相似文献   

5.
Russian Journal of Ecology - The study of macrozoobenthos in the Middle and Lower Volga reservoirs has revealed stable cenotic complexes of Ponto-Caspian and Ponto-Azovian species, which are...  相似文献   

6.
Unique mountain-steppe ecosystems in the Southern Urals have retained a high level of species and cenotic diversity, despite fragmentation and isolation. Specific features of these ecosystems are described.  相似文献   

7.
Nine lakes in the Arkhangelsk oblast were analyzed with respect to their morphometry, hydrology, and hydrochemistry, and their zooplankton was studied for three years. The data on zooplankton abundance, biomass, the ratio of filter-feeders and predators, the Shannon index of species diversity, and average individual weight of zooplankters were obtained. Differences in the structure of zooplanktonic cenoses were revealed in lakes differing in morphometric parameters, prevailing ions (HCO3 , SO4 2–), and their concentration.  相似文献   

8.
As a result of monitoring spatial changes in the cenotic structure of plant communities at the taiga-extrazonal steppe boundary on the western coast of Lake Baikal, models of taiga-steppe communities reflecting the formation, dynamics, and genesis of forests in the taiga zone have been constructed. Changes in the species composition of communities, mesophytization of steppes, the expansion of moss synusiae characteristic of polydominant dark conifer and light conifer taiga forests, active forest invasion into steppe areas, and the presence of dark conifer tree species in light conifer forests have been revealed.  相似文献   

9.
Changes in zooplankton developing under the effect of waste products from water-loving bird colonies were studied in water bodies of different types. The trophic status index in the nesting area showed no difference from its background values in an oligomesotrophic water body but was decreased in mesoeutrophic and eutrophic-hypertrophic water bodies. The abundance and biomass of zooplankton in the oligomesotrophic and mesoeutrophic water bodies were consistently higher than background values, while in the eutrophichypertrophic water body they were higher only at the beginning and in the middle of the nesting period. Irrespective of the trophic state of water body, the species diversity of zooplankton in the zone of impact from bird colonies was increased, but the number of dominant species remained unchanged, and no mass development of species indicating high organic load was observed; the proportion of Rotifera in the total abundance and biomass of zooplankton was decreased, that of Copepoda was increased, and the abundance of Cladocera was found to increase with the degree of overgrowing. Among possible explanations, this specific response of zooplankton is most likely due to changes in the ratio of nitrogen and phosphorus in the water.  相似文献   

10.
The stages of ontogeny and morphogenesis of the common chicory were characterized on the basis of long-term observations. A comparative analysis of seed productivity was performed, and the pool of viable seeds in the soil was determined. The ecological–cenotic relationships and the types of population strategy of the species were estimated.  相似文献   

11.
Some results of the ecocenotic analysis of forest and bog mosses, widespread or locally occurring in the taiga zone of West Siberia, are described. The species were compared with respect to their edaphic requirements, and a relationship was observed between geographic variation in cenotic parameters and changes in macroconditions of the physical environment, primarily in lithologic, geomorphological, and climatic conditions. The results of analysis confirmed the existence of such a relationship, but moss species proved to differ in their response to changes in physiographic conditions.  相似文献   

12.
长江天鹅洲故道浮游动物群落结构及水质评价   总被引:2,自引:0,他引:2  
于2011年4月~2012年1月按季度对长江天鹅洲故道浮游动物进行了采样调查。共检出浮游动物87种,其中原生动物22属38种,占总种类数的437%;轮虫25属36种,占总种类数的414%;枝角类8属9种,占总种类数的103%;桡足类4种,占总种类数的46%。浮游动物的年平均密度为25 7119 ind/L,以原生动物和轮虫为主,分别占总密度的937%和56%;年平均生物量为36 mg/L,以原生动物和枝角类为主,分别占总生物量的319%和281%。15种优势种中9种为富营养水体指示种。绿急游虫、双叉尾毛虫、长圆膜袋虫和小链巨头轮虫全年形成优势,而针簇多肢轮虫、缘板龟甲轮虫、角突臂尾轮虫在春、夏、秋季形成优势,螺形龟甲轮虫只在春秋形成优势。绿急游虫、双叉尾毛虫、长圆膜袋虫等富营养水体指示种在受污染较多的6和10号两处采样点数量较多。按现存量法和浮游动物优势种群法判定,天鹅洲故道属于富营养类型,与根据Shannon Weaver多样性指数和Pielou均匀度指数的评价为中污染水平的结果一致。同时对浮游动物种类组成小型化的形成原因进行了分析讨论  相似文献   

13.
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   

14.

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.

  相似文献   

15.
The structural-temporal organization of a murine rodent community in the taiga has been studied near Lake Teletskoe, Mountain Altai. The results show that the long-term dynamics of indices characterizing community diversity depend mainly on changes in the structure of dominance rather than on the population dynamics of species. The distribution of species in the factor space corresponds to their preference for certain biotopes, from dry to relatively moist. An analysis of relationships within the rodent community has revealed the synchronous dynamics of species abundance and antiphase pattern of changes in the structural indices of dominant species.  相似文献   

16.
湖北省雨涝灾害的指标和时空分布特征   总被引:5,自引:1,他引:4  
在总结全国各地和湖北省现有雨涝灾害指标的基础上,考察粮、棉、油等农业生产需要,新建了一个有别于前人的不有较强农业意义的雨涝灾害指标,并用此指标讨论湖北省雨涝灾害的时空分布特征,比较符合实际情况。  相似文献   

17.
林分空间结构是指林木在林地上的分布格局,以及林木之间树种、大小、分布等空间关系。林分空间结构决定了树木之间的竞争势及其空间生态位,在很大程度上决定了林分的稳定性、发展的可能性和经营空间的大小。研究目的在于揭示麻栎混交林林分空间结构与物种多样性特征,为林分空间结构调整和物种多样性保护提供理论依据。利用混交度、大小比数和角尺度3种空间结构参数,以及丰富度指数、Shannon Wiener指数、Pielou指数等物种多样性数量指标,分析了青阳县麻栎混交林林分空间结构以及群落物种多样性特征。结果表明:乔木层优势树种麻栎多为中度以下混交,小叶栎和枫香多为强度和极强度混交;麻栎在空间大小和重要值对比上占有优势地位,小叶栎处于次要地位,枫香处于劣势地位为受压树种;从林分平面布局上看,该林分空间分布多为随机分布。分层物种丰富度和Shannon Wiener指数依次是乔木层<草(含藤)本层<灌木层;而均匀度Pielou指数则是乔木层<灌木层<草(含藤)本层;生态优势度Simpson指数为乔木层>草本层>灌木层;灌木层有17科18属21种植物,淡竹占优势地位,野茉莉、山胡椒等占亚优势地位;草本层有10科12属13种植物,禾叶土麦冬占优势地位,其次是求米草、爬山虎等。林分空间结构和物种多样性数量特征分析结果均表明该森林类型具有稳定结构的群落特征。〖  相似文献   

18.
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   

19.
The results of studies on transformations of the floristic diversity of forest ecosystems under the effect of human activity in the southern and middle taiga subzones of the Komi Republic are reviewed. It is shown that the change of dominants in the tree layer leads to the formation of specific biotopes and, as a consequence, to changes in floristic complexes and the cenotic roles of species in the lower layers of forest communities. In the study region, the -diversity of forest communities is determined mainly by two environmental factors: soil fertility and acidity. The factor of illumination has only a slight effect on the -diversity of taiga forests, which is especially clear in the group of deciduous forest formations.__________Translated from Ekologiya, No. 3, 2005, pp. 180–185.Original Russian Text Copyright © 2005 by Degteva.  相似文献   

20.
为探明长江口沿岸碎波带浮游动物的分布与刀鲚仔稚鱼摄食的关系,2006年7~12月每月大潮期间在长江口沿岸碎波带设置13个站位点,用浮游Ⅰ型生物网(口径30 cm,网目0.2 mm)在表层拖曳采集浮游动物78次,采集到浮游动物72种,平均密度 3 278.95 个/网;用小型拖网(1 m×4 m,网目1 mm)拖曳234次,采集到刀鲚仔稚鱼 37 170 尾,平均密度158.85尾/网。通过胃含物分析共鉴定刀鲚仔稚鱼饵料生物15种(类)(浮游动物11种,浮游幼体4类),平均摄食密度1.306个/尾。研究结果表明:前弯曲期仔鱼偏好摄食哲水蚤、剑水蚤和枝角类;弯曲期仔鱼偏好摄食猛水蚤和桡足类桡足幼体;后弯曲期仔鱼除偏好摄食桡足类幼体以外,也偏好摄食游泳能力较强的糠虾;稚鱼对糠虾有极强的偏好。水温和盐度对刀鲚仔稚鱼的摄食量影响较小;浮游动物分布并不直接影响刀鲚仔稚鱼分布,相关性较小。  相似文献   

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