淡水鱼类功能生态学研究进展

在全球变化和人类活动的影响下,生物多样性正以前所未有的速度丧失,全球生物正经受第六次生物多样性危机。淡水生态系统是最脆弱的生态系统之一。淡水鱼类作为淡水生态系统的重要组成部分,承受着日趋严重的气候变化、栖息地退化、生物入侵和过度捕捞等压力,面临巨大的威胁。在此背景下,如何准确评估鱼类种群和群落对环境变化的响应,以及鱼类群落结构和功能的变化对生态系统功能的影响是淡水鱼类多样性和淡水生态系统保护的关键问题。近年来,淡水鱼类功能生态学的快速发展为解答这一问题提供了一个框架。系统地介绍了淡水鱼类功能生态学主要研究内容、方法、进展及其应用,并着重介绍了淡水鱼类功能特征及其与环境的关系、环境变化下的功能生态学响应研究。据此提出了淡水鱼类功能生态学未来的重点研究方向,指出了其在鱼类多样性保护和资源利用等领域的应用前景。     

The ecology of the Turbellaria with special reference to the freshwater triclads

To attempt a complete review of turbellarian ecology in the time and space available would result in superficiality. Therefore, I have restricted this account to the four basic ecological processes which have and continue to determine flatworm distribution and abundance. These are: (1) historical or zoogeographical events which permit or prevent a species from reaching a habitat; (2) physiological limitations of the species vis à vis the habitat; (3) access to suitable energy sources and (4) the effects of competition, predation and parasitism, referred to collectively as bionomic processes.     

Putting the meio- into stream ecology: current findings and future directions for lotic meiofaunal research

• 1 There is a paucity of research on epigean freshwater lotic meiofauna. This may result from a previous emphasis on interstitial (groundwater and hyporheic) meiofauna and/or a reliance on sampling methodologies in lotic systems which are inappropriate for meiofauna.
• 2 Meiofauna contribute much to the diversity of lotic ecosystems. Species lists for seven streams reveal that meiofauna contribute 58–82% of total species numbers, with rotifers and chironomids dominating most systems. The absence of taxonomic keys for most meiofaunal taxa in large areas of the world precludes a wider analysis of their contribution to lotic diversity and an assessment of biogeographical patterns and processes.
• 3 The trophic and functional role of meiofauna in lotic ecosystems is unclear. There are few estimates of meiofaunal production in freshwaters and biomass spectra have produced conflicting results for lotic meiofauna. Present static estimates suggest that the contribution of meiofauna to lotic productivity and biomass is small to moderate, but further studies incorporating a temporal component may provide a more realistic picture of the total contribution of meiofauna to biomass size spectra.
• 4 Meiofauna differ from macroinvertebrates in several respects apart from size and conceptual models for lotic ecosystems should include all metazoans if they are to be truly representative.
• 5 Information on the basic ecology of certain lotic meiofauna (i.e. nematodes, tardigrades, microturbellarians) is urgently required. For those groups whose distributional patterns are better understood (e.g. microcrustaceans), the mechanisms underpinning these patterns should be explored. It is essential that the importance of meiofauna is recognised by lotic ecologists; the only realistic way forward is for greater collaboration among meiofaunal ecologists and taxonomists and other lotic scientists.

     

Biogeography and ecology of freshwater diatoms in Subantarctica: a review

Subantarctica is situated between the Antarctic and the Subtropical Convergence and consists of the islands in the southern Atlantic, Indian and Pacific Oceans. Diatoms are an important component of all Subantarctic aquatic, moss and soil habitats. Taxonomic studies reveal a high diversity and species richness in both the present-day and the fossil diatom flora. Planktonic diatoms are almost completely absent. A similarity analysis of the diatom composition from different localities in the southern zone (below 40°S) resulted in a biogeographical zonation. Three regions could be formed, based on their diatom composition: Subantarctica, Maritime Antarctica and the Antarctic Continent. The diatom communities in the different regions are all characterized by a high proportion of cosmopolitan species. A second feature of the southern diatom floras is the decreasing diversity when moving southwards.     

工业生态学的内涵与发展

作为一门发展不到20a的综合性交叉学科,工业生态学目前需要界定其学术范畴和理论基础.首先评述了工业生态学的4个主要领域:(1)社会代谢是工业生态学起源最早也是发展最为成熟的领域.它提供了宏观层次上观察和测量经济发展与物质流动关系的方法和工具,但需要进一步细化物质流动图景和加强流动机制的解释;(2)工业共生是工业生态学最具特征的领域.它实质上是人们出于观察视角的转变而对工业体系的重新认识.逻辑严谨且规则统一的解释框架有助于工业共生理论的发展和实践;(3)基础设施与产业相互选择且协同演进,二者共同构成了城市的物质基础,而城市又是更大范围内区域经济系统的子集.这一组工业生态学的研究对象需要处理产业全球化与社会和生态要素本土化的矛盾;(4)工业发展的可持续性是工业生态学关注的核心目标,而多样性和复杂性给其研究带来了很大的挑战.这提醒我们要避免陷入简单化、还原论或机械论的陷阱,多开展实证研究.最后,从本体论、方法论和隐喻3个标准给出了工业生态学的初步界定,并指出4个重要的努力方向.     

Distribution and ecology of freshwater sponges in Connecticut

A survey of Connecticut lakes and rivers revealed the presence of 7 species of freshwater sponge: Spongilla lacustris, Ephydatia muelleri, Eunapius fragilis, Anheteromeyenia ryderi, A. argyrosperma, Corvomeyenia carolinensis, and Corvospongilla novaeterrae in order of decreasing frequency of occurrence. Corvomeyenia carolinensis has not been reported previously beyond its type locality in South Carolina. In addition, microscleres of Spongilla lacustris, Anheteromeyenia-like megascleres, Ephydatia muelleri-like megascleres, and smooth megascleres (amphioxeas), which could not be assigned to a particular species, were found in surface sediments from lake cores. Spongilla lacustris inhabiting small rivers produced brown, thick-capsuled gemmules during the summer and yellow, thin-capsuled gemmules during the fall. The thick-capsuled gemmules, but not the thin-capsuled gemmules, are tolerant of desiccation; and populations of Spongilla lacustris and Ephydatia muelleri survived severe drying of their habitats during the summer.     

基于组织生态理论的资源型产业集群可持续发展

产业集群作为一种极具特色的产业组织形式,对区域经济的发展具有重要的驱动作用,已成为各国各地区发展经济的重要政策工具.然而,产业集群也有可能带来诸如经济衰退、环境污染等负面影响,特别是资源型产业集群除了资源枯竭带来的结构性风险外,其自身产业链单向的、线性的集群内部结构特征也决定了和其他类型的集群相比具有更大的衰退风险.基于组织生态理论的研究发现该类产业集群表现出较低程度的多样性和活力以及过分凸现出专业性的特点是退化的主要原因,在此基础上,对资源型产业集群可持续发展提出了相应的对策建议.     

Implications of scale for patterns and processes in stream ecology

Abstract Although the scale-dependence of ecological patterns and processes is recognized by freshwater ecologists, current knowledge of scale effects is rudimentary and non-quantitative. We review issues of spatial and temporal scale in this paper to highlight conceptual problems relating to scale and some potential solutions. We present examples of how the spatial scale of a study influences observed patterns and their interpretation, and discuss how the size of an experimental arena influences the degree to which the dynamics of studied populations are influenced by exchange processes (immigration and emigration). The results of small-scale field experiments in streams will often be strongly influenced by the per capita exchange rates of organisms and differences in exchange rates may explain differences in the perceived effects of stream manipulations across scales. Spatial extent also influences the amount of spatial heterogeneity within a study site or arena, with important consequences for the outcome of predator-prey interactions. We suggest that changes in the availability of prey refuges may help explain why predator manipulations in streams appear to weaken as arena size increases. We also recommend that new techniques for decomposing and quantifying spatial heterogeneity be applied to characterize scale-dependent variation in freshwater systems. Lastly, we discuss the pitfalls of mismatching the temporal scale of experiments and models. Models incorporating spatial heterogeneity and the behaviour of organisms are needed to predict the short-term outcome of perturbations in streams, whereas models predicting long-term dynamics will need to integrate the impacts of episodic disturbance and all life history stages of organisms. In general, we recommend that freshwater ecologists undertake more multi-scale sampling and experimentation to examine patterns and processes at multiple scales, and make greater attempts to match the scales of their observations and experiments to the characteristic scales of the phenomena that they investigate.     

淡水螯虾生理生态学与环境毒理学研究进展

综述了我国2种主养的淡水螯虾(克氏原螯虾和红螯螯虾)在生理生态学与环境毒理学方面的研究进展。总结了淡水螯虾的环境条件(盐度、温度和pH)适应范围、毒性污染物(氨氮、亚硝酸盐、重金属和农药等)的半致死浓度和安全浓度,以及环境胁迫和毒性污染物暴露对淡水螯虾生长、组织结构、生理代谢和免疫功能等的影响,为淡水螯虾养殖的水环境监测与调控提供参考依据。     

A method for quantifying conservation value in lentic freshwater habitats using desmids as indicator organisms

A method is presented for quantification of aquatic nature conservation value based on desmid assemblages present. Species richness (indicative of internal structural and functional differentiation of the ecosystem), the occurrence of rare taxa (often indicative of particular environmental conditions) and the presence of species indicative of ecosystem maturity are the parameters chosen to determine conservation value. For the sake of utility, schemes have been developed to transform the values scored for the various parameters to a simple scale ranging from 0 to 10, relative to regional and historical standards. By way of illustration, two examples are presented. The first shows the decline of desmid-related conservation value along a gradient of increasing eutrophication in a series of interconnected shallow lakes, the other illustrates the course of this value through time in a polluted and subsequently restored moorland pool.     

Role of fungi in freshwater ecosystems

There are more than 600 species of freshwater fungi with a greater number known from temperate, as compared to tropical, regions. Three main groups can be considered which include Ingoldian fungi, aquatic ascomycetes and non-Ingoldian hyphomycetes, chytrids and, oomycetes. The fungi occurring in lentic habitats mostly differ from those occurring in lotic habitats. Although there is no comprehensive work dealing with the biogeography of all groups of freshwater fungi, their distribution probably follows that of Ingoldian fungi, which are either cosmopolitan, restricted to pantemperate or pantropical regions, or in a few cases, have a restricted distribution. Freshwater fungi are thought to have evolved from terrestrial ancestors. Many species are clearly adapted to life in freshwater as their propagules have specialised aquatic dispersal abilities. Freshwater fungi are involved in the decay of wood and leafy material and also cause diseases of plants and animals. These areas are briefly reviewed. Gaps in our knowledge of freshwater fungi are discussed and areas in need of research are suggested.     

Metabarcoding of freshwater invertebrates to detect the effects of a pesticide spill

Biomonitoring underpins the environmental assessment of freshwater ecosystems and guides management and conservation. Current methodology for surveys of (macro)invertebrates uses coarse taxonomic identification where species‐level resolution is difficult to obtain. Next‐generation sequencing of entire assemblages (metabarcoding) provides a new approach for species detection, but requires further validation. We used metabarcoding of invertebrate assemblages with two fragments of the cox1 “barcode” and partial nuclear ribosomal (SSU) genes, to assess the effects of a pesticide spill in the River Kennet (southern England). Operational taxonomic unit (OTU) recovery was tested under 72 parameters (read denoising, filtering, pair merging and clustering). Similar taxonomic profiles were obtained under a broad range of parameters. The SSU marker recovered Platyhelminthes and Nematoda, missed by cox1, while Rotifera were only amplified with cox1. A reference set was created from all available barcode entries for Arthropoda in the BOLD database and clustered into OTUs. The River Kennet metabarcoding produced matches to 207 of these reference OTUs, five times the number of species recognized with morphological monitoring. The increase was due to the following: greater taxonomic resolution (e.g., splitting a single morphotaxon “Chironomidae” into 55 named OTUs); splitting of Linnaean binomials into multiple molecular OTUs; and the use of a filtration‐flotation protocol for extraction of minute specimens (meiofauna). Community analyses revealed strong differences between “impacted” vs. “control” samples, detectable with each gene marker, for each major taxonomic group, and for meio‐ and macrofaunal samples separately. Thus, highly resolved taxonomic data can be extracted at a fraction of the time and cost of traditional nonmolecular methods, opening new avenues for freshwater invertebrate biodiversity monitoring and molecular ecology.     

Linking soil process and microbial ecology in freshwater wetland ecosystems

Soil microorganisms mediate many processes such as nitrification, denitrification, and methanogenesis that regulate ecosystem functioning and also feed back to influence atmospheric chemistry. These processes are of particular interest in freshwater wetland ecosystems where nutrient cycling is highly responsive to fluctuating hydrology and nutrients and soil gas releases may be sensitive to climate warming. In this review we briefly summarize research from process and taxonomic approaches to the study of wetland biogeochemistry and microbial ecology, and highlight areas where further research is needed to increase our mechanistic understanding of wetland system functioning. Research in wetland biogeochemistry has most often been focused on processes (e.g., methanogenesis), and less often on microbial communities or on populations of specific microorganisms of interest. Research on process has focused on controls over, and rates of, denitrification, methanogenesis, and methanotrophy. There has been some work on sulfate and iron transformations and wetland enzyme activities. Work to date indicates an important process level role for hydrology and soil nutrient status. The impact of plant species composition on processes is potentially critical, but is as yet poorly understood. Research on microbial communities in wetland soils has primarily focused on bacteria responsible for methanogenesis, denitrification, and sulfate reduction. There has been less work on taxonomic groups such as those responsible for nitrogen fixation, or aerobic processes such as nitrification. Work on general community composition and on wetland mycorrhizal fungi is particularly sparse. The general goal of microbial research has been to understand how microbial groups respond to the environment. There has been relatively little work done on the interactions among environmental controls over process rates, environmental constraints on microbial activities and community composition, and changes in processes at the ecosystem level. Finding ways to link process-based and biochemical or gene-based assays is becoming increasingly important as we seek a mechanistic understanding of the response of wetland ecosystems to current and future anthropogenic perturbations. We discuss the potential of new approaches, and highlight areas for further research.     

Biodiversity: towards a unifying theme for river ecology

1. A broadened concept of biodiversity, encompassing spatio‐temporal heterogeneity, functional processes and species diversity, could provide a unifying theme for river ecology. 2. The theoretical foundations of stream ecology often do not reflect fully the crucial roles of spatial complexity and fluvial dynamics in natural river ecosystems, which has hindered conceptual advances and the effectiveness of efforts at conservation and restoration. 3. Inclusion of surface waters (lotic and lentic), subsurface waters (hyporheic and phreatic), riparian systems (in both constrained and floodplain reaches), and the ecotones between them (e.g. springs) as interacting components contributing to total biodiversity, is crucial for developing a holistic framework of rivers as ecosystems. 4. Measures of species diversity, including alpha, beta and gamma diversity, are a result of disturbance history, resource partitioning, habitat fragmentation and successional phenomena across the riverine landscape. A hierarchical approach to diversity in natural and altered river‐floodplain ecosystems will enhance understanding of ecological phenomena operating at different scales along multidimensional environmental gradients. 5. Re‐establishing functional diversity (e.g. hydrologic and successional processes) across the active corridor could serve as the focus of river conservation initiatives. Once functional processes have been reconstituted, habitat heterogeneity will increase, followed by corresponding increases in species diversity of aquatic and riparian biota.     

Integrating molecular tools into freshwater ecology: developments and opportunities

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An experimental analysis of species sorting and mass effects in freshwater bacterioplankton

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Ecology of freshwater snails in south-western Nigeria. I: Distribution and habitat preferences

Dry and rainy season investigations of diverse freshwater habitats in south-western Nigeria revealed fourteen species of snail comprised of nine pulmonates: Biomphalaria pfeifferi Krauss, Bulinus globosus Morelet, Bulinus rohlfsi Clessin, Lymnaea natalensis Krauss, Physa ( Aplexa) waterloti Germain, Bulinus forskali Ehrenberg, Gyraulus costulatus Krauss, Ferrissia sp, Segmentorbis sp. and five prosobranchs namely, Lanistes libycus Morelet, Lanistes ovum Peters, Pila wernei Philippi, Potadoma moerchi Reeve and Melanoides tuberculata Müller.The influence of diverse chemical and physical properties of water on their occurrence as well as interspecific and snail-plant relationships are discussed and maps showing the distribution of the species encountered are presented. Among the intermediate hosts of Schistosoma, B. globosus was widely distributed and common, B. pfeieri was also widely distributed but infrequent and B. rohlfsi was rare.     

农林生态系统界面生态学初探

对界面生态 的概念、界面生态学的主要研究内容?界面生态学在农林复合生态系统中的应用进行了系统的论述,农林复合生态系统中树木对农作物的作用机制主要体现在以空气为介质的光、热、水分竞争的地上界面和以土壤为介质的养分、水分竞争的地下界面上,界面上物质、能量、信息的交换和传递反映了农林复合生态系统中树林和农作物的作用机理。     

Recent sedimentation in a freshwater reservoir in SW-Finland: The diatomological and chemical evidence of sediments on the development of the water body

A freshwater reservoir was dammed from the Baltic Sea in 1965. The recent sediments and the processes of accumulation in the reservoir have been investigated. The physical, chemical and diatom analyses of the sediments were carried out at 5 sampling points in order to dinstinquish the freshwater sediments from the underlying brackish sediments as well as to date the freshwater sediments. The pattern of sedimentation in the reservoir is described on the basis of these results and conclusions are drawn regarding the development of the water body. In interpretating the diatomological and the chemical results from the recent sediments certain common features are highlighted.