Distribution of Zooplankton along the Longitudinal Profile of Two Disturbed Small Rivers of the Upper Volga Basin

The abundance and trophic structure of zooplankton along the longitudinal profile of two typical rivers in the Yaroslavl sector of the Volga region are determined by anthropogenic and zoogenic factors. The distribution of zooplankton under the influence of these factors is described by the concept of patch dynamics. The abundance of zooplankton reaches the highest values in the ameliorated upper reaches of rivers and in beaver ponds.     

Activity of Beavers as an Ecological Factor Affecting the Zooplankton of Small Rivers

The role of beavers in the transformation of small rivers is elucidated by analyzing the taxonomic and trophic structure of zooplankton in ponds differing in age, water flow rate, and the degree of overgrowing with higher aquatic plants. The building activity of beavers in the river system promotes the formation of biotopes of the ecotone type, in which the planktonic invertebrate community develops some features similar to or different from those of zooplanktonic communities from lakes and rivers undergoing anthropogenic eutrophication. The main distinctive feature of response to this activity in zooplankton is that its development reaches a plateau at the early and middle stages of succession, compared to that under conditions of anthropogenic eutrophication. For small rivers, the concept of zoogenic eutrophication (in addition to anthropogenic) is proposed.     

Fish Communities of Small Ponds in the Udmurt Republic: Structural Features and Trends in Anthropogenic Successions

The ichthyofauna of 20 small ponds in the Udmurt Republic was studied to estimate the dependence of fish species abundance on pond size and anthropogenic load, as well as trends in the succession of dominant species complexes in ponds exposed to the prevailing impact of agricultural activity. Changes in the ecological structure of fish communities in small ponds upon an increase in the anthropogenic load were analyzed. Some specific features of the species composition of ichthyofauna in technogenic pond biocenoses were revealed.     

基于RDI指数的云南1960~2013年#br# 旱涝变化特征分析

利用云南省40个气象站逐日降水量和蒸发量数据,采用RDI指数研究云南旱涝灾害的时空分布特征。结果表明：云南年际、季节旱涝与历史记录十分一致,1960~2013年云南年RDI指数呈下降趋势,表现为变干趋势,但不显著;2001年以前发生雨涝年的强度和站次比较干旱年明显,在此之后,发生干旱年的强度和站次比较雨涝年明显。季节尺度上,春季呈显著的变湿趋势,夏、秋、冬季呈不显著的变干趋势;春、夏季分别突变于1980年和1965年。从空间分布上来看,年、夏、秋、冬季整体以滇南和滇东北呈变干趋势,而滇西北呈变湿趋势;春季除滇东北外,其余区域均呈变湿趋势;年际、季节干旱频率以滇西北、滇西南、滇东南较高;年、春、夏、秋季重旱频率以滇中和滇东十分突出;年、夏、秋季特旱频率均以滇东北十分突出,春季滇中和滇东北极易发生特旱;冬季以滇中重旱频率较高,特旱极易发生在滇西北、滇西南、滇东北。年际、季节雨涝频率以滇西、滇东南较突出。年重、特涝频率以滇西南十分突出;春季重涝频率以滇西南和滇中较突出,特涝频率以滇中和滇东南较突出;夏季重、特涝频率均以滇西北较高;秋季重涝频率以滇西北较高,特涝频率以滇东南较高;冬季重涝频率以滇东南较突出,特涝频率以滇西北较高。 关键词： 云南省;RDI指数;旱涝变化趋势;时空特征     

Cladocerans under conditions of small river damming by man and beavers

In beaver ponds, the species diversity, abundance, biomass, and production of cladocerans and the amount of food consumed by them have increased and the composition of dominant species has changed as compared to those in the stretches of small rivers with running water or dammed by man. The stimulating effect of water from a beaver pond has been confirmed in laboratory experiments. The average number of juvenile Ceriodaphnia affinis produced by one female was considerably greater in this water than in the water from flowing and dammed (by man) river stretches.     

人工重建的水生植物群落演替动态研究

水生植物群落在湖泊生态修复过程中作用显著,但目前人工重建的水生植物群落抗外界干扰能力弱,群落稳定性差,这就需要我们对人工重建的水生植物群落结构及其演替的生态学过程进行研究,从而探索受损群落的修复途径。于2003年在富营养化水体中采用物理生态工程进行了水生植物群落的重建研究,对群落演替动态变化过程进行了持续3年的观测。结果表明：水生植物之间发生生态位重叠时,其结果往往是以一个物种取代另一个物种,随着生态位重叠程度下降,种间关系和群落结构趋于稳定;而当物种空间位置错开时,生长期相近的物种共存则变为可能,因此在群落的构建过程中应当避免同时引入生态位重叠较高的物种,应注意植物间时间序列及空间结构的分离;此外还通过物种间的竞争表现,对几种常见水生植物构建的群落稳定性做了初步探讨.     

Experience in syntaxonomic and ordination analysis of progressive succession in cutover areas of boreal light conifer forests in the Southern Urals

Progressive succession of plant communities has been studied in cutover areas of bilberry-green moss forests of the alliance Dicrano-Pinion in the central upland part of the Southern Urals. The results are presented concerning the alpha-diversity and phytosociological spectrum of communities at different stages of succession.     

Resilience of the poorest: coping strategies and indigenous knowledge of living with the floods in Northern Namibia

In Northern Namibia, the climate is highly polarised between dry and wet seasons, and local communities have lived with these varying weather extremes for centuries. However, the recent changes in socio-environmental dynamics—associated with urbanisation, inappropriate spatial planning, and population growth—have disturbed the river system in the area. These changes, together with torrential seasonal rains, have aggravated the social impacts of the flood events. By using various qualitative and quantitative data sources, and comparative analyses between the flood dynamics in urban and rural environments, this research studies local residents’ coping strategies to endure the irregular flood events from the perspective of socio-ecological resilience. Particular interest is placed on the learning processes that enhance the residents’ capability to cope and the role of indigenous knowledge. Indigenous knowledge (IK) has been emphasised as a source of resilience in both theory and practice, as it is built upon learning from past experiences of natural hazards. The findings reveal that the floods are a result of complex and relational development without the necessary linear relationship between the causes and effects. The abrupt socio-ecological changes, together with the multiple stressors related to poverty, have made residents more vulnerable to the flood events and attenuated the communities’ coping strategies based on IK. Instead of focusing on the communities’ capacity to self-organise, the focus of resilience building needs to be directed to emphasising the broader socio-political processes, which are making the communities vulnerable in the first place.     

不同鱼类养殖方式对长江中游湖泊浮游植物群落的影响及其季节动态

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。     

金沙江干流浮游植物群落结构特征及其时空变化

为研究金沙江干流浮游植物群落结构及其时空分布特征,于2017～2018年春秋两季对干流14个断面进行调查分析。调查结果显示:金沙江干流水域共分布浮游植物8门100种(含变种),主要由硅藻(56%)、蓝藻(22%)、绿藻(11%)组成,浮游植物密度变化范围为0.019 3×10~6～0.341 0×10~6cells/L,浮游植物生物量变化范围为0.016～0.434 mg/L,各江段存在显著性差异。Shannon多样性指数变化范围1.168～2.519,Pielou均匀度指数变化范围为0.559～0.876,Margalef指数变化范围为1.573～3.36,各江段多样性指数变化各异,金沙江干流水环境综合评价为中污染状态。等级聚类和排序结果表明,2017、2018年的春秋两季样本点群落均分为3组。上中下游在不同季节、年份里表现出不同程度的相似性,由于不同断面的环境差异造成了浮游植物群落的时空差异。时间上,金沙江干流浮游植物群落结构上每个季节演替明显,既有延续也有交替;空间上,采样点从上游至下游浮游植物群落越均匀旺盛,具有较明显的空间趋异性,聚类和排序较好的揭示了金沙江干流各江段浮游植物分布组成、种类数量和生境的相似性。     

Specific Structural Features of Zooplankton in Lakes Differing in Trophic Status: Species Populations

The index of cenotic significance and other indices calculated on its basis were used for revealing specific structural features of zooplanktonic communities in lakes differing in productivity. The results showed that new indices (complexity coefficient, index of cenotic significance of dominant species, and integrated cenotic significance of the zooplankton) strongly correlate with the trophic status of the water body and are more responsive to changes in the structure of the community than the Shannon–Weaver index of species diversity. The results confirm the hypothesis that the structure of zooplankton is simplified in the course of lake eutrophication.     

Seasonal variation in photosynthesis in relation to differing environmental factors of dominant plant species in three successional communities in Hangzhou Bay Wetlands,East China

We investigated the ecophysiology (physiological ecology) of plant succession within a coastal wetland community. The photosynthetic characteristics of six plants were studied; Scirpus mariqueter and Carex scabrifolia in early successional communities, Phragmites communis and Tamarix chinensis in mid successional communities, and Salix matsudana and Imperata cylindrica in later successional communities. Environmental factors were concurrently determined for each community. Relationships between photosynthetic and environmental factors were analyzed by path analysis, and the dependence of photosynthesis on particular environmental factors was shown to vary between plants in the differing successional communities. Ability to cope with irradiation appears to be one of the most important factors influencing plant succession. The increasing stratification of plant communities following colonization of new coastal land necessitates differing physiological strategies and photosynthetic dynamics in the later colonizing plants.     

On shrimp,salt and security: livelihood risks and responses in South Bangladesh and East India

Bangladesh and India are among the world’s most populous but also most vulnerable countries to environmental risks. In addition to storms, sea-level rise, floods and droughts, local communities face a multitude of pre-existing and concomitant economic and socio-political risks. To understand these risks and how communities respond to them is critical in securing community livelihoods. We therefore ask what are the livelihood risks; how do they impact the human security of environment sensitive communities in Satkhira, Bangladesh and in Odisha, India; and, what are the responses of these communities to the livelihood risks? The communities studied in Bangladesh depend mainly on the shrimp and fish resources of the Sundarbans mangrove forest. The two communities researched at Lake Chilika in India depend on fishing and salt farming, respectively. The field research, conducted in 2012 and 2013, shows that the communities face multiple and interacting livelihood risks. While storms and floods are common environmental risks in both countries, related livelihood risks are case-specific. In Bangladesh, attacks by criminals are the major threat to human well-being, while in India, it is violent conflict between lake users. Unsustainable resource extraction is found in both study countries. In Bangladesh, shrimp farming weakens the flood protection, while in India, illegal prawn farming marginalizes poorer lake users. Accessing loans and labor migration are responses observed in both countries. We conclude that adaptation to environmental changes needs to be sensitive to the interaction between governance, local institutions and socio-economic developments.     

Sociopolitical drivers and environmental outcomes of protected area downgrading and degazettement in Cambodia

Regional Environmental Change - Climate change has severe impacts on the livelihoods of West-African communities with the floods of the late 2000s and early 2010s serving as factual evidence....     

The state of European beaver (<Emphasis Type="Italic">Castor fiber</Emphasis> L., 1758) population in Kurgan oblast

The results of studies on European beaver population dynamics in Kurgan oblast are presented. Recommendations are given concerning rational management of beaver stock.     

Specific features of zooplankton community in industrially polluted areas of Subarctic Lake Imandra (Monche, Belaya, and Molochnaya Bays)

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.     

The role of planktonic organisms in accumulation and transfer of radioactive contaminants in the cooling reservoir of a nuclear power plant

The results of long-term studies (1985–2006) on the state of planktonic communities and their capacity for accumulation of radioactive contaminants in the cooling reservoir of the Beloyarsk Nuclear Power Plant (BNPP) have been summarized. The changes in the population density and biomass of planktonic organisms have been estimated in different water areas of the Beloyarsk Reservoir. The levels of radionuclide accumulation by phyto- and zooplankton in the reservoir and technological channels of the BNPP have been determined. The contributions of two nuclear power enterprises (the BNPP and the Institute of Reactor Materials) to the accumulation of radionuclides by planktonic organisms have been evaluated. The rates of radionuclide accumulation by phyto- and zooplankton have been estimated and compared with those of other components of the aquatic biocenosis.     

Effect of water pH and total dissolved solids on the species diversity of pelagic zooplankton in lakes: A statistical analysis

Statistical analysis of the combined influence of lake surface area (S), water pH, and total dissolved solids (TDS) on the formation of zooplankton communities in lakes has been made on the basis of available data on the number of species (N _sp ) of pelagic zooplankton in 256 lakes of the temperate zone of Europe, Asia, and North America. Graphic analysis and analysis of variance have shown that extremely high or extremely low values of pH and TDS inhibit lake zooplankton. If the value of one of these factors is extremely high, any increase in the other factor is favorable for the inhibited zooplankton, and this second factor determines the value of N _sp .     

Dynamics of plant communities in insular pine forests of Krasnoyarsk forest-steppe

The dynamics of vegetation have been studied in forest-steppe pine (Pinus symvestris L.) forests affected by anthropogenic factors such as felling and fires. Gradient analysis has been used to reveal specific ecological features of plant communities and trace the main directions of succession. The results show that these forests are at different stages of progressive succession, with the development of theircommunities following similar trends over the past few decades.