赣江干流底栖动物群落结构与环境因素的关系

底栖动物是河流水生态系统的重要组成部分,对水环境的变化极其敏感.为分析赣江干流底栖动物群落结构特征及其与环境因素的关系,本研究于2018年8月、2019年1月及4月在赣江干流布设12个采样点进行底栖动物调查.赣江干流共检出底栖动物3门6纲24种属,上游的优势种分别为苏氏尾鳃蚓和铜锈环棱螺,中游的优势种为铜锈环棱螺和河蚬...     

大纵湖大型底栖生物群落结构及水质生物学评价

大纵湖位于长江、淮河两大水系交融的里下河地区洼地中心地带,是江苏省级规划保护的重点湖泊之一。近20 a来,在人类活动影响下,大纵湖生态环境受到了严重挑战。底栖动物是水生态系统中的重要组成部分,在能量流动和物质循环中起着承上启下的作用。于2015～2016年对大纵湖底栖动物群落分布特征进行了监测分析。结果表明:在调查期间,大纵湖共采集出底栖动物10种(属),其中寡毛类、摇蚊幼虫、软体动物及其它底栖动物平均密度分别为132.27,100.52,82.02,5.29 ind./m~2,平均生物量分别为1.52,0.61,168.74,0.02 g/m~2。底栖动物密度与生物量均呈现出时空分布不均匀的特征。大纵湖底栖动物优势种主要为苏氏尾鳃蚓、霍甫水丝蚓、中国长足摇蚊和环棱螺。基于调查结果,选用4种不同的生物指数(BPI生物学指数、Shannon-wiener指数、Goodnight生物学、Wright指数)对大纵湖进行水质生物评价,结果表明大纵湖目前处于轻度-中度污染阶段。     

长荡湖底栖动物群落结构及与环境因子关系

为了研究长荡湖底栖动物群落结构组成以及影响因子,与2018年1—12月逐月对长荡湖湖区10个采样点进行了调查分析。长荡湖底栖动物共检出13种,主要为寡毛类、摇蚊幼虫以及软体动物3大类;通过优势度指数结果表明长荡湖底栖动物优势种为颤蚓(Tubifex)、黄色羽摇蚊(Chironomus flaviplumus)、刺铗长足摇蚊(Tanypus punctipennis)和梨形环棱螺(Bellamya purrificata); RDA多元统计分析结果显示,TN、CODMn、水深和总溶解固体是影响底栖动物优势种的主要水环境因子。     

2020年洞庭湖水生生物群落结构特征及水生态评价研究

为了解洞庭湖水生生物群落结构并进行水生态评价，在2020年采用Shannon-Wiener指数对洞庭湖浮游植物、浮游动物和底栖动物进行调查，并采用水生态环境质量综合指数法(WQI)对洞庭湖进行水生态评价。结果表明：(1)洞庭湖浮游植物共检出6门73属，优势种类有伪鱼腥藻(Pseudanabaena sp.)、直链藻(Melosira sp.)、尖头藻(Raphidiopsis sp.)、平裂藻(Merismopedia sp.)和十字藻(Crucigenia sp.),全湖平均密度为95.7×10⁴个/L。(2)洞庭湖浮游动物共检出48属，优势种是广生多肢轮虫(Polyarthra vulgaris)、螺形龟甲轮虫(Keratella cochlearis)、象鼻蚤(Bosmina sp.)以及无节幼体(nauplius),全湖平均密度为74个/L。(3)底栖动物共检出57种，优势种类有指突隐摇蚊(Cryptochironomus rostratus)、多足摇蚊(Polypedilum sp.)、铜锈环棱螺(Bellamya aeruginosa)、河蚬(Corb...     

邵伯湖底栖动物群落结构调查研究及水质生态评价

2018年1—12月对邵伯湖进行了底栖动物监测分析,共鉴定出底栖动物16种,底栖动物主要优势种为苏氏尾鳃蚓、霍甫水丝蚓、红裸须摇蚊和环棱螺。底栖动物密度介于46～115 ind./m~2,平均密度为81 ind./m~2。底栖动物生物量介于2.928～23.405 g/m~2,平均生物量为13.665 g/m~2。通过Wright指数、Goodnight指数、BPI生物学指数和Shannon-Wiener多样性指数对邵伯湖进行了水质生态评价。     

固城湖底栖动物群落结构及水质生态评价

2015年3月～2016年2月对南京市高淳区饮用水源地固城湖开展了全年的底栖动物监测与分析,并通过Wright指数、Goodnight指数、BPI生物学指数和Shannon-Wiener多样性指数对固城湖进行水质生态评价。结果表明:全年12个月共鉴定出底栖动物21种(属),其中摇蚊科幼虫种类最多,共计11种,寡毛类8种,软体动物2种;主要优势种为苏氏尾鳃蚓(Branchiura sowerbyi)、中国长足摇蚊(Tanypus chinensis)、内摇蚊属(Endochironomus sp.)和环棱螺(Bellamya sp.)。四种指数评价结果显示固城湖水质现状处于轻度-中度污染时期,属于富营养化过程的初中期。     

基于底栖动物生物完整性指数的赣江干流健康评价

构建河流底栖动物生物完整性指数指标体系是评价河流生态系统健康的重要基础。根据2018-2019年期间在赣江干流12个采样点的底栖动物数据,鉴定出赣江干流底栖动物分为3门6纲13科共24种属,其中优势种有3种,分别为铜锈环棱螺、苏氏尾鳃蚓和大沼螺。通过对18个候选生物指标进行分布范围判别、能力分析以及相关性分析,筛选出总分类单元数、总生物量、甲壳动物和软体动物的个体相对丰度、耐污类群的生物量百分组成完整性指数评价体系,然后采用比值法统一生物参数的量纲,累加各生物参数分值得到B-IBI指数值。赣江干流的健康评价标准由B-IBI值的25%分位数值确定。结果表明：赣江干流12个采样点中的4个为健康,1个为亚健康,1个为一般,其余6个断面的健康状况均处于差或者极差状态,赣江干流生态系统整体上处于一般健康状态。     

昆承湖大型底栖动物时空分布及对环境修复的指示性

2015年对常熟市昆承湖的大型底栖动物进行了时空分布调查,开展了水质生物学评价与环境影响因子分析,并基于底栖动物分布特征对昆承湖2006—2012年环境修复工程效果进行初步评估。结果表明:4次调查共采集底栖动物12科22种,优势物种多为耐污型;底栖动物年均密度为38.3 ind/m~2,各季节密度分布存在差异,但均以摇蚊幼虫类密度占优,其次为寡毛类和软体动物,底栖动物年均生物量为24.54 g/m~2,主要为软体动物所贡献;底栖动物Shannon-Wiener多样性指数值(H')、Margalef多样性指数值(D)、Pielou均匀度指数值(J)和BI指数值表明,昆承湖总体处于中度污染状态;不同湖区因污染程度等环境因素不同,底栖动物物种、密度与生物量分布存在差异,典范对应分析表明水体DO、浊度、TN、TP等水质因子以及底泥TN、总有机物等是影响底栖动物分布的主要环境因子;昆承湖实施封闭湖泊口门、深度清淤等环境修复措施后,水质总体得到改善,但湖泊水深增大、基底形态单一以及水生植物分布少等因素也影响了湖泊底栖动物密度与种群分布。     

清淤工程对固城湖小湖区水生态环境影响研究

以高淳区固城湖小湖区生态清淤工程为例,比较清淤工程实施前后底泥营养物含量、释放通量以及水生生物变化。结果表明,生态清淤工程增加了固城湖蓄水容量,削减了小湖区内源污染负荷,清淤工程实施后短期内改变了底栖动物和水生植物群落结构和组成。建议加强水利工程调度和水位调控,跟踪监测清淤水域水生态恢复过程,促进清淤区域底栖动物和水生植被恢复。     

流溪河底栖动物功能摄食类群组成及其水生态指示作用

流溪河是广州最重要的河流,开展流溪河系统性监测与评估是生态系统健康管理的基础。2019年枯水期(3月)和丰水期(9月)对流溪河底栖动物进行了野外原位采样,研究底栖动物功能摄食类群的时空分布特征,并通过底栖动物功能摄食类群组成评价流溪河的生境状况。研究发现流溪河流域底栖动物以收集者为主要类群,其次为刮食者和捕食者,滤食者和撕食者较少。上游和中游样点以中等耐污收集者(四节蜉和河蚬)和耐污收集者(摇蚊)为优势类群,而下游样点以耐污收集者(摇蚊)为绝对优势类群。环境因子显著影响底栖动物功能摄食类群分布,枯水期流速和NO₃是关键环境因子;丰水期SiO₂和流速是关键环境因子。基于底栖动物功能摄食类群组成的流溪河生态系统属性分析结果表明,流溪河大部分样点为异养生态系统;流域河岸带不健康;河流纵向运输能力多处于不健康状态;除上游的个别采样点外,捕食者调控能力较为正常;除受挖沙干扰的采样点外,流域生境稳定性维持较好。     

Benthic macroinvertebrate community structure in Lake Taihu,China: Effects of trophic status,wind-induced disturbance and habitat complexity

Lake Taihu, the third largest lake in China, is subjected to severe eutrophication and cyanobacterial blooms as a result of development and urbanization. However, little is known about the macroinvertebrate assemblages and their relationship with eutrophication and other environmental factors in this lake. To characterize the community structure of macroinvertebrates and to examine the benthos-environmental relationships in Lake Taihu, a quarterly investigation was conducted from February 2007 to November 2008. A total of 42 taxa was recorded; Limnodrilus hoffmeisteri, Rhyacodrilus sinicus, Corbicula fluminea, Bellamya aeruginosa, Tanypus chinensis and Gammarus sp. dominated the community in abundance and biomass. Cluster analysis and one-way analysis of similarity (ANOSIM) identified three groups of stations that had significantly different macroinvertebrate communities. Stations in the north bays and three river mouths had the lowest diversity and were dominated by pollution-tolerant species such as L. hoffmeisteri and R. sinicus while Gonghu Bay, the Central Region and the Western Region contained intermediately diverse communities mainly dominated by C. fluminea. Diversity and evenness were highest in the East Bays where aquatic macrophytes were abundant; the zoobenthos were characterized by gastropods. One-way ANOVAs revealed that environmental characteristics differed significantly among the three groups of stations. Canonical correspondence analyses showed that community structure and spatial patterns of macroinvertebrates in Lake Taihu were strongly correlated to three ecological factors—trophic status, wind-induced disturbance and habitat complexity. Our results could provide valuable information that could be used by managers and policy makers to evaluate and modify restoration practices.     

阳澄西湖围堰施工中悬浮物输移扩散数值模拟

为了探究涉水工程建设对湖泊系统的影响,基于二维非稳态水动力模型,对阳澄西湖水动力进行数值模拟,并在水动力模拟正确的基础上建立悬浮物预测模型,模拟了不同风向、施工工况下阳澄西湖隧道围堰施工扰动水体所引起的阳澄西湖悬浮物输移扩散,分析了围堰施工对水域环境的影响.模拟结果表明:围堰抽排水引起的悬浮物浓度增加对水生态影响最为严...     

近30年太湖沉水植物优势种遥感监测及变化分析

利用1985—1986年、1995—1996年、2004—2006年和2014—2015年多时相遥感影像数据,构建了水生植物分类决策树模型,结合沉水植物的生活史差异,研究太湖近30年沉水植物优势种的演替模式。4个时期的沉水植物遥感分类总体精度与Kappa系数依次为64.86%和0.59,70.83%和0.65,63.93%和0.50,64.94%和0.60。研究表明:1985—2015年马来眼子菜由东山湾向西山岛、东太湖向南太湖扩张,竺山湾、梅梁湾的苦草呈锐减的趋势,近年来梅梁湾的沉水植物只有菹草1种,湖心区一直未监测到沉水植物,东太湖沉水植物分布面积最广、种类最多。近30年太湖沉水植物演替主要经历4个阶段,依次为苦草-眼子菜型、小眼子菜型、金鱼藻-伊乐藻型和眼子菜-伊乐藻型阶段。水体富营养化和围网养殖是沉水植物演替的主要原因。     

Restoration of small lakes through cooperative management: A suitable strategy for poverty‐laden areas in developing countries?

Lake Rupa is a small, subtropical, shallow lake with a surface area of 100 ha situated 600 m a.s.l. in Central Himalaya, Nepal. This degraded lake was studied between 2000 and 2006, with the goal of determining whether or not it could be restored by a community‐based cooperative of local people living in its catchment. Main threats to the lake, its aquatic life and its very existence include encroachment by excessive aquatic vegetation, sedimentation, and low in‐lake concentrations of dissolved oxygen (DO). Small lakes (≤ 500 ha) are relatively prone to the process of ‘succession and climax’, although they also can be of social, environmental and ecological importance. Thus, their disappearance could spark social chaos and disorder in areas already having to cope with other rapid environmental changes. This means that credible mechanisms for revitalizing or protecting small lakes are an important goal. Accordingly, a lake cooperative of 329 households living in close vicinity to Lake Rupa was formed in 2002, by prioritizing traditional fishers, women and other deprived community members with the goals of respecting the citizenry and equity. Following the cooperative's campaigns directed at weed removal and fish stocking, encroachment of vegetation on the lake margins was halted, its aquatic weeds became under control, and its fisheries improved. In addition to the cooperative's restoration activities, several water quality parameters, including water transparency and DO and chlorophyll‐a concentrations, were monitored on a monthly basis. The measured water transparency was inconsistent, exhibiting large variations between 2000 and 2003. Relatively low, but consistent, values, however, were measured after 2004. The results imply that the removal of weeds, and sufficient nutrients and solar radiation are subsequently available to the lake's phytoplankton communities. Supporting this notion is that the chlorophyll‐a concentration spiked to 205 µg L⁻¹ in November 2006, the water transparency became consistent, and the DO concentration increased to >3.8 mg L⁻¹ during the critical months (March–May) after 2004. These water quality indicators indicated improvement in the degraded Lake Rupa, suggesting that the establishment of cooperatives such as that highlighted in this study could be a powerful and sustainable mechanism for restoring degraded lakes in similar socioeconomic settings by maintaining equity, by connecting communities with their resources, and by facilitating integrity, equity, citizenry and social justice.     

Stimulating a Great Lakes coastal wetland seed bank using portable cofferdams: implications for habitat rehabilitation

Coastal wetland seed banks exposed by low lake levels or through management actions fuel the reestablishment of emergent plant assemblages (i.e., wetland habitat) critical to Great Lakes aquatic biota. This project explored the effectiveness of using portable, water-filled cofferdams as a management tool to promote the natural growth of emergent vegetation from the seed bank in a Lake Erie coastal wetland. A series of dams stretching approximately 450 m was installed temporarily to isolate hydrologically a 10-ha corner of the Crane Creek wetland complex from Lake Erie. The test area was dewatered in 2004 to mimic a low-water year, and vegetation sampling characterized the wetland seed bank response at low, middle, and high elevations in areas open to and protected from bird and mammal herbivory. The nearly two-month drawdown stimulated a rapid seed-bank-driven response by 45 plant taxa. Herbivory had little effect on plant species richness, regardless of the location along an elevation gradient. Inundation contributed to the replacement of immature emergent plant species with submersed aquatic species after the dams failed and were removed prematurely. This study revealed a number of important issues that must be considered for effective long-term implementation of portable cofferdam technology to stimulate wetland seed banks, including duration of dewatering, product size, source of clean water, replacement of damaged dams, and regular maintenance. This technology is a potentially important tool in the arsenal used by resource managers seeking to rehabilitate the functions and values of Great Lakes coastal wetland habitats.     

基于水生植物修复的玄武湖生态水位研究

在野外采样调查水生植物种类、种群现状和空间分布的基础上,基于湖泊形态分析法和生物空间最小需求法确定了玄武湖最低生态水位,并进一步考虑水生植物的水位需求,制定了水生植物不同生长阶段的生态水位调控方案。结果表明:玄武湖水生植物种类丰富但覆盖度不高,为13.2%,沉水植物的覆盖度很低,为2.1%;玄武湖最低生态水位为9.6 m,萌发期水位为9.9 m时,有利于水生植物尤其是沉水植物的萌发,能达成30%的水生植被覆盖度目标;夏季水位为9.8 m时,能保障湖泊防洪安全,控制过度生长的荷花等挺水植物,促进玄武湖总体水生植物的生长与修复。     

七浦塘引水对阳澄湖河网水环境影响的模拟研究

为准确地衡量七浦塘引水工程的运行方式对阳澄湖及周边河网产生的影响,基于太湖水量水质模型设计了7种数值实验,从引水量和雨型两个角度对七浦塘引水对阳澄湖及周边河网造成的影响进行了评估,并定义了河网总体水质达标率作为评估标准。结果表明:七浦塘引水使得水量向阳澄湖北线和南线河道集中,在改善阳澄湖西湖水质的同时恶化了中东湖的水质;七浦闸引水量在20~40 m3/s之间时对提高河网水质总体达标率最为有利;引水对河网水质的影响具有显著的空间差异性;在不同雨情条件下,七浦塘引水调度均可在一定程度上改善河网和湖体的水质。     

阳澄湖入湖河道水质变化及污染物通量分析

分析阳澄湖主要入湖河道的近几年的水质状况,找出水质较差的几条河流以及主要的污染物指标,计算其入湖污染物通量,并进行趋势分析;比较分析外围进入准保护区的污染物通量和准保护区直接入湖的污染物通量的大小,找出污染物来源的主要区域及各河道各项污染物通量比重。结果表明:阳澄湖主要入湖河道水质无恶化趋势,基本维持在原有水平;阳澄湖西湖的主要入湖河道中,污染物通量主要来自里塘河;近5年准保护区直接入湖的总污染物通量大于外围入准保护区的总污染物通量;准保护区内NH3-N通量的年均增长率最大,是主要污染指标。     

Three-dimensional Water Quality and SAV Modeling of a Large Shallow Lake

This study presents the Lake Okeechobee Environment Model (LOEM), a three-dimensional (3D) hydrodynamic, sediment, water quality, and submerged aquatic vegetation (SAV) model of Lake Okeechobee, Florida. The LOEM is developed under the framework of the EFDC model (Hamrick 1992). Lake Okeechobee is the largest subtropical lake in North America (1,730 km²), it is very shallow (mean depth 2.7 m), and it includes a littoral habitat that makes up 20% of its area. The LOEM is calibrated, verified, and validated to 3 years of water quality and SAV data. The water quality results are consistent with observed data from 25 locations in the lake. The model is capable of reproducing key water quality characteristics of the lake without having to resort to extensive, site-specific parameter manipulations. The SAV model is calibrated using measured SAV data in the lake. The SAV model is capable of representing the spatial and temporal variations of SAV variations in the lake well. The LOEM is applied to study water quality and SAV processes in the lake. The model results are consistent with observed data indicating that algal growth in the lake is primarily nitrogen limited in the summer and nitrogen and light co-limited in the winter. Lower water elevation generally leads to larger SAV area. SAV can have positive impact on the lake water quality by reducing algae concentration. The calibrated, verified, and validated LOEM model serves as a useful tool to support lake management.