太湖藻型富营养化对水生高等植物的影响及植被的恢复

太湖的五里湖是典型的藻型富营养化湖泊,水质污染严重,水生高等植物消失。在该湖的物理生态工程围区内外,用盆吊繁殖试验、壮芽直播试验及人工水生植物群落套种栽培试验,研究藻型富营养化湖泊中影响水生高等植物生长、繁殖的主要水环境因子。结果表明,水体透明度是制约沉水植物和浮叶植物幼苗成活及生长的主要因子。在水体透明度较低、水下光照不足时,沉水植物生长受水下光照的影响大于浮叶植物,水下光照严重不足时,沉水植物的幼苗大量死亡。１９９５～１９９７年,在围区内成功地组建了包括漂浮植物、浮叶植物及沉水植物的１５个不同的水生高等植物群落。恢复和重建的水生高等植物群落能够有效地净化富营养化水体。     

城市水体生态修复技术初探——以徐州市为例

探讨了利用典型沉水植物密齿苦草修复城市水体的技术,评价了生态浮岛技术对城市水体的净化作用,探索了滤食性动物对水体的净化作用。研究表明,沉水植物恢复、生态浮岛和滤食性动物吸收转化技术可用于修复城市水体,恢复水体的自净能力,逐步增加水生生态系统的生物多样性,完善水生生态系统的结构及其生态功能。     

利用三角帆蚌控制水华的初步研究

富营养化已成为全球面临的主要环境问题之一。目前,治理水体富营养化,主要从两方面来进行:一是控制外源性营养物质输入,如截污分流和污水集中处理,主要用于控制点源污染;二是减少内源性营养物质负荷,如微生物修复、底泥疏浚、化学法、人工湿地、水生植被恢复等,其目的是控制面源污染和加快湖泊的恢复速度[1—5]。上述研究方法单一或联合采用,已在一些湖泊取得一定的效果。本文以汉阳莲花湖为例,在实验室多次模拟试验的基础上,在富营养化水体中引入三角帆蚌,研究利用三角帆蚌控制浮游植物的过量生长。1材料与方法莲花湖已经严重富营养化,水质…     

沉水植物生长和腐解对富营养化水体氮磷的影响机制研究进展

沉水植物作为湖泊、河流等生态系统的主要高等植物, 在修复富营养化水体中的作用日益受到重视, 合理利用沉水植物是去除富营养化水体氮磷的有效途径。沉水植物对水体氮磷的迁移转化影响包括生长和腐解两个阶段。文章综述了沉水植物生长对富营养化水体氮、磷的净化效果和净化机制, 分析了沉水植物腐解对氮、磷迁移转化的持续影响, 并提出了今后沉水植物净化氮、磷的研究方向, 为沉水植物推广应用于修复富营养化水体提供理论基础。     

湖滨带退化生态系统的恢复与重建

湖滨带是水陆生态交错带的一种类型,在湖泊流域生态系统中发挥着重要作用,具有较高的生态、社会和经济价值.湖滨带的功能包括:缓冲带功能、保持生物多样性及生境保护功能、护岸功能和经济美学价值.湖滨带退化的原因主要是人为因素引起的生物群落结构的逆向演替及生态功能下降,退化湖滨带生态恢复与重建的理论基础是恢复生态学,其生态恢复技术可划分为三大类:湖滨带生境恢复与重建技术、湖滨带生物恢复与重建技术、湖滨带生态系统结构与功能恢复技术.云南洱海湖滨带近3年的生态恢复与重建试验的生态调查结果表明,试验区水生植被得到恢复,水质净化作用明显,藻类得到抑制,浮游动物的构成和数量发生变化,湖滨带湿地生态系统的生物多样性和稳定性增加.     

河口地区牡蛎礁的生态功能及恢复措施

在许多温带河口区,牡蛎礁是具有重要生态功能的特殊生境。牡蛎礁在净化水体、提供栖息生境、保护生物多样性和耦合生态系统能量流动等方面均具有重要的功能。近100年来,由于过度采捕、环境污染、病害和生境破坏等原因,许多温带河口区牡蛎种群数量持续下降,河口生态系统的结构与功能受到破坏,富营养化越来越严重。为了修复河口生态系统、净化水质和促进渔业可持续发展,近20年来,世界各地开展了一系列牡蛎礁的恢复活动,尤其美国在东海岸及墨西哥湾建立了大量的人工牡蛎礁,许多研究结果证实,构建的人工牡蛎礁经过2~3年时间,就能恢复自然生境的生态功能。本文介绍了我国首次牡蛎增殖放流工程-长江口南北导堤牡蛎礁,近2年的监测结果显示,长江口导堤牡蛎种群数量快速增长,附近水生生态系统的结构与功能得到明显改善。最后,针对目前牡蛎礁恢复过程中存在的不足,提出了需进一步研究的课题,包括牡蛎基础生物学(病害和分子系统进化),牡蛎礁恢复的关键技术、科学程序及成功的评价标准等。     

短小芽孢杆菌溶藻效应研究

随着全球水体富营养化的加剧,有害藻类水华的暴发日趋频繁,其造成的环境和经济问题日益引起人们的重视,寻求有效的水华和赤潮防治途径势在必行。溶藻细菌作为水生生态系统中生物种群结构和功能的重要组成部分,对维持浮游植物生物量平衡具有非常重要的作用。不少研究认为水华和赤潮的突然消亡可能与溶藻细菌的感染有关。有些溶藻细菌能够分泌细胞外物质,对宿     

利用人工围隔研究沉水植被恢复的生态效应

近几十年来,随着水体富营养化加剧和其它人类活动影响,一些湖泊,尤其是我国长江中下游地区浅水湖泊中,沉水植被锐减甚至消失。如武汉东湖,６０年代十分繁茂的沉水植被现已濒临灭绝。沉水植被作为主要初级生产者,在水生态系统中起着一定的作用。在退化湖泊生态系统重建与恢复中,重建沉水植被是关键性的步骤。本研究利用人工围隔,在富营养化水体中重建沉水植被,通过与近旁无沉水植被的湖区对照,从水体理化性质、浮游植物叶绿素ａ含量以及原生动物群落结构与多样性几个方面,研究沉水植被恢复的生态效应,以期为退化湖泊生态系统的重…     

东湖围隔（栏）中的植被恢复对水中氮的影响

利用大型围隔研究自然水体的某些生态过程具有真实准确、易于控制等优点 ,2 0世纪 80年代以来 ,国内陆续开展了一些研究[1～ 4 ] 。水体富营养化是目前我国湖泊存在的普遍问题 ,恢复水生植被可有效改善水质 ,减轻富营养化程度。武汉东湖(Ｅ114°2 3’ ,Ｎ30°33’)是一个典型的浅水城郊湖泊 ,已严重富营养化 ,为重建其水生植被 ,恢复其良性生态系统 ,在东湖建立了两个大型围隔和一个围栏 ,对其中的水生植被恢复及水质变化等方面进行了定位研究 ,旨在为重建和优化东湖水生植被 ,改善其水质提供借鉴。1　研究方法实验区位于东湖的汤林湖区。设…     

水体的富营养化及其治理对策

富营养化是当前水体面临的主要问题,本文着重阐述了水体富营养化对水质、水生生物、人类及自然环境的影响,分析富营养化的现象及其成因,并提出了内源控制及防治,外源控制及治理等相关对策。     

Managing water quality with aquatic macrophytes

The principal sources of water for human use are lakes, rivers, soil moisture and relatively shallow groundwater basins. Water quality in lakes and reservoirs is subjected to the natural degradation, processes of eutrophication and the impacts of human activities. Water quality problems can often be as severe as those of water availability but less attention has been paid to them, particularly in developing countries. Currently additional sustainable ways to mitigate the degradation of water quality are being researched all over the world. Phytoremediation is one of the serious efforts towards the sustainability. Most of the aquatic macrophytes are naturally occurring and well adapted for their surroundings. Aquatic macrophytes have the capability to remove excessive nutrient load from the water that otherwise cause eutrophication of the water body. Aquatic macrophytes absorb nutrient mineral ions from water column and influence metal retention indirectly by acting as traps for particulate matter, by slowing the water current and favoring sedimentation of suspended particles. Aquatic macrophytes also reduce sediment resuspension by offering wind protection. The use of aquatic macrophyte for treatment of wastewater to mitigate variety of pollution level is one of the most researched issues all over the world. Aquatic plant species are very specific for the uptake of nutrients. Owing to this specificity, the selection of the aquatic plant species is one of the skilled tasks prior to the design of a water treatment facility. An effort has been made in this review to cover the most researched aquatic flora for mitigation purposes and their possible use in a mesocosm as the selection of an appropriate aquatic plant specie reduce the time and cost of the treatment processes.     

Assessing the responses of aquatic macrophytes to the application of a lanthanum modified bentonite clay,at Loch Flemington,Scotland, UK

Loch Flemington is a shallow lake of international conservation and scientific importance. In recent decades, its status has declined as a result of eutrophication and the establishment of non-native invasive aquatic macrophytes. As previous research had identified the lake bed sediments as an important source of phosphorus (P), the P-capping material Phoslock^® was applied to improve water quality. This article documents the responses of the aquatic macrophyte community by comparing data collected between 1988 and 2011. Summer water-column total P concentrations decreased significantly and water clarity increased following treatment. Aquatic plant colonisation depth increased and plant coverage of the lake bed extended. However, the submerged vegetation remained dominated by the non-native Elodea canadensis Michx. Aquatic macrophyte community metrics indicated no significant change in trophic status. Species richness and the number of ‘natural’ eutrophic characteristic species remained broadly similar with no records of rare species of conservation interest. Loch Flemington is still classified as being in ‘unfavourable no change’ condition based on its aquatic macrophytes despite the water quality improvements. The implications of these results are discussed in relation to the future management of Loch Flemington and in the wider context of trying to improve our understanding of lake restoration processes.     

正交试验法分析环境因子对苦草生长的影响

苦草(Vallisneria natans),是我国长江中下游淡水水体中常见的沉水植物种类。通过室内模拟正交试验的方法,研究不同光照强度、温度和总氮浓度(3光照×3温度×3总氮浓度)对苦草生长的影响。结果表明:(1)苦草在5320lx光照强度、10℃、2—4mg/L水体总氮浓度的条件下生长良好。实验所设100%(12000lx)和50%(5320lx)光照条件下苦草均可正常生长;但对于30℃的高温胁迫耐受性较差;苦草在总氮浓度为4mg/L的水体中各生长指标达到最大值,2mg/L或8mg/L的总氮浓度均会抑制其生长。(2)5320lx的光照强度和10℃的温度对苦草光合色素的合成较为有利;而单纯总氮浓度的变化对苦草光合色素的合成影响不大。(3)苦草的生理活性在高于12000lx或低于1025lx的光强、高于30℃的温度以及8mg/L的总氮浓度下均会受到一定程度的抑制。(4)方差分析结果显示,苦草生长发育的过程中,光照强度和温度是主效环境因子;上述3个环境因子对苦草光合色素的合成均有极显著的影响,并且光强与温度的交互作用对其也有显著影响;光照强度、温度以及这两个环境因子的交互作用为影响苦草生理活性的主效因子。苦草作为不能形成冠层的基生叶莲座型沉水植物,对光强要求不高,对低温的耐受性较好,但较不耐高营养盐浓度,因此,在得到一定修复的富营养化水体中,可以作为秋、冬季水生植物恢复和重建的关键物种。     

光强、温度、总氮浓度对黑藻生长的影响

为寻求沉水植物生长的主效环境因子,探求富营养化水体沉水植物的衰亡机理并选择治理富营养化的先锋植物,实验选择长江中下游常见沉水植物种黑藻(Hydrilla verticillata),利用正交试验设计,通过室内静态模拟实验研究三种主要环境因子光照强度、温度、总氮浓度及其互作对黑藻断枝生长的影响。结果表明:光照强度和温度为影响黑藻生长的主效环境因子,并且光强与温度的交互作用对黑藻生长有较为显著的影响,具体表现为黑藻的生长指标(株高、生物量、分枝数)、光合指标(叶绿素a+b浓度、叶绿素a/b、叶绿体总色素含量)和生理活性指标(根活力、可溶性糖含量、MDA含量)的变化均与这两个环境因子及其互作呈显著相关;总氮浓度的变化对黑藻生长影响不大,在2-8 mg/L的总氮浓度下,黑藻均可以正常生长。根据本实验黑藻生长指标、光合色素含量以及生理活性在不同环境因子组合的变化结果可知,黑藻在5320-12000 lx光照强度、20°C-30°C、4-8 mg/L水体总氮浓度的条件下生长良好,故推测黑藻可作为春夏季富营养化水体中恢复和重建沉水植被的先锋工具种。       

武汉月湖水生植被重建的实践与启示

通过生物操纵、浮水植物和植物浮岛原位净化、岸边人工湿地净化和科学种植等措施,2－3年内,在长江中游地区、面积为0.66km2、水质为劣Ⅴ类的重富营养湖泊武汉月湖重建了以菹草和伊乐藻为优势种的沉水植物先锋群落,2005年春季的沉水植物盖度达到45％,提高了透明度。利用水位低、透明度相对高的冬季种植伊乐藻、菹草等适合冬春季生长的沉水植物是建立沉水植物先锋群落的一个有效途径。重污染水体过低的透明度是重建沉水植被的主要限制因子,在低水位或较高透明度时期,水生植物可以耐受相对较高的污染负荷,并且在有条件降低水位时,会大大提高重建沉水植被的成功率。重建并保持长期稳定的水生植被必须截污,并把营养盐浓度削减到一定范围内。水生植被重建初期是最脆弱的时期,水位、污染负荷等生态因子的较大波动很容易破坏植物群落,在这一时期要尽量保持关键因子的稳定,注意控制浮萍的扩张,使形成的生态系统逐步走向成熟。清除鱼类对提高水的透明度有重要作用,但必须伴随着水生植被的恢复或重建才能维持长久的良好效果。     

Eutrophication: An ecological vision

The present review deals with the studies conducted on the impact of phosphorus on growth of aquatic plants causing eutrophication in well-known water bodies the world over. The review covers the definition and concept of eutrophication and the adverse effects on quality and ecosystem functioning. The eutrophication of several water bodies leads to significant changes in the structure and function of the aquatic ecosystem. Several activities of human interest, including navigation and power generation, are hampered. A large number of lakes in the United States, Europe, and Asia have recently been found to be highly eutrophic. Water, the precious fluid, is not uniformly distributed throughout the surface of the earth. Most of the water bodies world over are surrounded with densely populated human settlement areas and agricultural fields. The size of smaller water bodies in human settlement areas is on the decrease with rise in population. After treatment, a large quantity of sewage from the households is regularly discharged into the water bodies. The runoff brings down fertilizers and other chemicals from agricultural fields. The phosphorus contained in these effluents is known to promote excessive growth of plants. This review is an account of the role, sources, and monitoring of phosphorus, as well as its cycle. The natural phosphorus cycle originating from the weathering of phosphate rock is now a two-way operation, due to significant addition of phosphorus from anthropogenic sources. The detergents that are the major source of phosphorus inputs into water bodies (through sewage and drainage systems) have been thoroughly discussed. The major part of detergents comprises builders containing polyphosphate salts. An environment-friendly and effective synthetic builder is yet to be developed to replace existing phosphorus containing builders of detergents. The utility of the alternative builders available has been reviewed. Nitrogen has also been reported to affect the phytoplankton production in eutrophic waters in temperate regions. Several environmental factors have also been found to add to the problem of eutrophication in addition to nutrients. Several limiting factors—namely, CO₂ level, temperature, pH, light, and dissolved oxygen—are known to affect eutrophic water bodies. Eutrophication not only results in algal bloom but also affects wetland plants and activates early onset of natural succession at a relatively faster rate. Some of the plant species reported and studied world over are the best indicators of the level of eutrophication. The studies on the change in structure, function, and diversity of the ecosystem have been used as parameters to assess the level of eutrophication. In several countries adequate control measures have been adopted in to control eutrophication. But these measures were found to be only partially effective in controlling the phosphorus unloading in water bodies. In this review some control measures are suggested, with emphasis on biological control. The review concludes by taking into account the ecological prospective of the water—the precious fluid and a basis of life on the earth.     

Odonates as biological indicators of grazing effects on Canadian prairie wetlands

Abstract.  1. Aquatic macro-invertebrates have frequently been used as biological indicators in lotic environments but much less commonly so in lentic habitats. Dragonflies and damselflies (Order Odonata) satisfy most selection criteria for lentic bioindicators of grazing impacts.
2. Intensive cattle grazing affects most of the Canadian prairie pothole region but the effects of grazing on wetlands are poorly understood.
3. Here the vegetation structure and invertebrate community composition of 27 prairie potholes in Alberta, Canada were studied and compared. Wetlands were evenly divided into three treatments of different grazing regimes.
4. Removal of emergent vegetation by cattle grazing decreased odonate abundance and reproductive effort. Shorter Scirpus acutus stems resulted in significantly fewer damselflies (Suborder Zygoptera) and lower reproductive efforts.
5. Overall odonate diversity was affected by the height of key plant species, highlighting the importance of the vegetation structure of both emergent vegetation for breeding and adjacent upland vegetation for nocturnal roosts. Wetland vegetation structure was more important than vegetation composition to the life history of odonates.
6. Wetland water quality parameters of nitrogen, phosphorus, total dissolved solids (TDS), and chlorophyll-a concentration did not change due to the presence of grazing cattle at wetlands so water quality influences were rejected as mechanisms of change.
7. Larval odonate diversity and abundance was positively correlated with overall aquatic macro-invertebrate diversity and abundance, hence it was concluded that the larval odonate community can be an accurate bioindicator of intactness and diversity of overall aquatic macro-invertebrate communities in Canadian prairie wetlands.     

水生甲虫系统发育研究进展

简要回顾了水生甲虫近十几年来各个分类阶元水平系统关系的研究历史,对代表性的水生甲虫类高级阶元系统发育关系进行了比较分析,总结了普遍存在的共识和争议.在研究进展中还介绍了分子生物学方法在水生甲虫系统发育研究中的尝试,虽然其研究结果还未能完全解决上述问题,但必将是对现有研究方法的补充.     

湖泊富营养化治理的生态工程

1996年对长春南湖的富营养化实施了生治理工作,调查结果表明,通过收获水生高等植物和鱼产品带出湖体的P量分别为149．6和189．9kg,通过蚌体生长固定的P量为153.4kg,三者合计492.9kg,与湖体会年P输入量大体持平,生态工程运转后,水质明显好转,湖水中的总P浓度逐年下降,浮游植物个体密度减小,种类数增加,生态工程是城市湖泊富营养化治理较为理想的方法。     

More than a barrier: The complex effects of ecotone vegetation type on terrestrial consumer consumption of an aquatic prey resource

Community structure and dynamics can be influenced by resource transfers between ecosystems, yet little is known about how boundary structure determines both the magnitude of exchanges and their effects on recipient and donor communities. Aquatic and terrestrial ecosystems are often linked by resource fluxes and riparian vegetation is commonly affected by anthropogenic alterations to land use or river hydrological regime. I investigated whether shrubs at the freshwater–terrestrial interface alter the supply, distribution and importance of aquatic prey resources to terrestrial consumers. Shrubs were predicted to alter the larval community composition of aquatic insects and the emergence of winged adults, thus affecting aquatic prey subsidies to terrestrial consumers. In addition, shrubs were hypothesized to alter the microclimatic suitability of the riparian zone for adult aquatic insects, act as a physical barrier to their dispersal and affect terrestrial community composition, particularly the abundance and type of predators that could benefit from the aquatic prey resource. Stable isotope dietary analyses and a survey of shrub‐dominated and open grassland riparian habitats revealed that larval densities of aquatic insects (EPTM: Ephemeroptera, Plecoptera, Trichoptera and Megaloptera) were higher in shrub than grassland habitats; however, reduced emergence and lateral dispersal in shrub areas led to lower densities of adults. The temperature and relative humidity of the riparian zone did not differ between the habitats. Ground‐active terrestrial invertebrate communities had a higher proportion of cursorial spiders in grassland, coinciding with greater abundances of aquatic prey. Aquatic prey contribution to cursorial spider diet matched adult aquatic insect abundances. Overall, riparian shrubs reduced the magnitude, or at least altered the timing, of cross‐ecosystem subsidy supply, distribution and use by consumers through mechanisms operating in both the aquatic and terrestrial ecosystems. Thus, the structure of ecosystem boundaries has complex effects on the strength of biological interactions between adjacent systems.