This paper is a review of research works concerning the nutrient transportation, transformation and exchange between water, sediment and biota in the lakes from the middle and lower reaches of the Yangtze River conducted in the context of project entitled “The Processes and Mechanism of Lake Eutrophication in Middle and Lower Reaches of Yangtze River”. All the lakes from this area are shallow lakes. According to the typical lake site research, the lakes from the middle and lower reaches of Yangtze River have a higher baseline of nutrition in the history. Normally the trophic status of these lakes can be categorized into medium-trophic or eutrophic Human activities have been enhanced during the last decades, which speed up the lake eutrophic process. Lake eutrophication control needs to reduce not only the external nutrient inputs from watershed but also the internal loading from the sediments. Investigations revealed that the lake sediments in this area are considerablly high in nutrition in which at most about 30% of phosphorus exists in the form of bio-available in the sediment. The surface sediment will exert great effects on the nutrient exchange between water-sediment interface via adsorption and release of nutrient. The nutrient release from the sediment in these shallow lakes is mainly in two ways, i.e. in the undisturbed condition the nutrient is released through diffusion created by the nutrient gradient from sediment to overlying water; whereas in disturbed condition, the nutrient release is determined by the hydrodynamic forcing intensity and the sediment resuspension. Metallic elements such as the iron, manganese and aluminium and the aerobic-anaerobic ambience will affect the release of nutrients. The disturbed release will increase the total nutrients in the water column significantly in the short period. At the beginning of sediment resuspension, the dissolved nutrient concentration will increase. This increase will be damped if the ferric oxide and aluminium are rich in sediment because of the adsorption and flocculation. This means that the lakes have capability of eliminating the nutrient loadings. Investigations for the lakes from middle and down stream of Yangtze River have suggested that most lakes have the self-cleaning capability. Dredging the control of the internal loading, therefore, is only applicable to the small lakes or undisturbed bays which normally are situated nearby the city or town and rich in organic materials in the sediment. In addition, the strong reduction condition and weak aeration of these lakes and bays make these small lakes and bays release much more bio-available nutrient and without much self-eliminating capability. Moreover, eutrophication induced algal bloom in these lakes will change the pH of water, which further induces the increase in the nutrient release. In turn, the increase in nutrient release promotes the growth of phytoplankton and results in severe algal bloom. For the heavily polluted water, research suggests that the biomass of bacteria and alkaline phosphatase activity will be higher corresponding to the higher concentration of nutrients, which accelerates the nutrient recycling between water, sediment and biota. Quick recycling of nutrient, in turn, promotes the production and biomass growth of microorganism and leads to more severe eutrophication. Further research work should focus on the nutrient transformation mechanism and the effects of microbial loop on the eutrophication.
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1.
太湖软体动物现存量及空间分布格局(2006-2007年) 总被引：5，自引：3，他引：2
2006年11月至2007年10月对太湖软体动物进行了一周年调查,软体动物在30个采样点的出现率为90.0%,采集的232份样品中共记录到9科12属12种,软体动物在分布区的年均密度和生物量分别为266ind./m2、102.2g/m2,河蚬(Corbicula fluminea)和铜锈环棱螺(Bettamya aeruginosa)是太湖软体动物的优势种,河蚬的出现率为90.0%,年均密度和生物量分别为174ind./m2、58.3g/m2,其主要分布在西南湖区(393-896ind./m2)和贡湖湾(393-552ind./m2);铜锈环棱螺的出现率为56.7%,年均密度和生物量分别为58ind./m2.61.6g,m2,主要分布在东太湖(140-299ind./m2).主成分分析结果表明,河蚬空间分布格局取决于生境类型和底质性质,而螺类的分布与水生植物的分布相一致,说明水生植物对螺类的分布有重要影响,这与经典的螺一草互惠理论相一致,比较1987-2006年太湖软体动物群落结构变化发现,20年来河蚬的高值区域已由梅梁湾、竺山湾转变为大太湖,河蚬个体大小趋于小型化发展(P＜0.001),而环棱螺小型化趋势并不显著(P=0.051). 相似文献
2.
2006年4月至2007年3月对长江支流清江二级支流———胡家溪的大型底栖动物群落结构和生产量进行为期一周年的调查和研究.结果表明,主要蜉蝣优势种小裳蜉(Leptophlebia sp.)、扁蜉(Electrogena sp.)、四节蜉(Indobaetis sp.)的生活史为一年三代,细蜉(Caenis sp.)为一年两代;小裳蜉的年均密度和年均生物量分别为407 ind./m2、1.00 g/m2;扁蜉为150 ind./m2、0.37 g/m2,四节蜉为232 ind./m2、0.30 g/m2,细蜉为91 ind./m2、0.17 g/m2.采用龄期频率法测算的周年生产量和P/B分别为:小裳蜉为441.42 g/m2(WW),14.3;扁蜉为434.88 g/m2(WW),7.6;四节蜉为747.21 g/m2(WW),15.0;细蜉为40.52 g/m2(WW),7.2.四种蜉蝣生产量的时间重叠比例相似系数较高,均大于0.55,这可能与四种蜉蝣的生境及食物资源较为相似有关. 相似文献
3.
太湖河蚬时空格局 总被引：14，自引：6，他引：8
2006年12月-2007年11月对太湖河蚬种群进行了周年逐月调查.河蚬在分布区的年均密度和生物量分别为265.7ind./m2和100.9g/m2,在夏、秋季均达到高值.根据壳长频数分布的周年变化,太湖河蚬一年一代,繁殖期主要在5-7月份.河蚬主要分布在贡湖湾、马迹山以南区域、西南湖区和小梅港沿岸区域.分析表明,太湖中河蚬的空间分布表现出明显的差异性,这种差异性受到多种因素的综合影响.在北部梅梁湾和竺山湾湖区湖泊中的低溶氧量是限制河蚬生长的最重要因素;在贡湖湾、马迹山以南湖区和西南部湖区,各种生境条件和底质性质适合河蚬的生长繁殖,其密度和生物量的最高值出现在贡湖湾的中心区域(820.0ind./m2,522.9g/m2);在东太湖湖区浮游植物密度较低,底质中有机质较少,食物来源是影响河蚬分布的较重要因素. 相似文献
4.
5.
南京玄武湖周丛动物数量和生物量的季节变化 总被引：1，自引：1，他引：1
用挂片法研究玄武湖周丛动物数量和生物量季节性变动,其优势种为褶累枝虫,钟形钟虫,沟钟虫,壶状臂尾轮虫和花箧臂尾轮虫。周丛原生动物数量和生物量在夏、秋季出现高峰,Ⅰ站数量最高达19952ind./cm~2,生物量为296.6μg/cm~2。Ⅱ站数量最高达16393ind./cm~2,生物量为246.5μg/cm~2。周丛轮虫在秋、冬季出现高峰,10月初Ⅰ站周丛轮虫数量为873ind./cm~2,生物量为958.3μg/cm~2。2月初Ⅱ站周丛轮虫数量为201ind./cm~2,生物量为257μg/cm~2。Ⅰ站年平均周丛动物数4661ind./cm~2,年平均生物量为量为391μg/cm~2;Ⅱ站周丛动物年平均数量为3037ind./cm~2,年平均生物量为150.6g/cm~2,因此Ⅰ站周丛动物数量和生物量都比Ⅱ站高。从指示生物的角度得出玄武湖水体富营养化程度是很严重的。 相似文献
6.
2014年4个季度对洞庭湖大型底栖动物进行调查,共记录底栖动物4门7纲58种,其中寡毛类7种,软体动物28种,水生昆虫19种,线虫1种,蛭类2种,钩虾1种.洞庭湖底栖动物平均密度为187.4 ind./m~2,软体动物是最主要的类群,平均密度为88.7 ind./m~2,占总密度的47.3%,寡毛类和水生昆虫的密度分别为24.1和27.8 ind./m~2,分别占总密度的12.9%和14.9%.河蚬(Corbicula fluminea)、铜锈环棱螺(Bellamya aeruginosa)、苏氏尾鳃蚓(Branchiura sowerbyi)、指突隐摇蚊(Cryptochironomus digitatus)和钩虾(Gammaridae sp.)为洞庭湖的优势种.典范对应分析表明,水温和溶解氧是影响洞庭湖底栖动物分布的关键环境因子.采用Shannon-Wiener多样性指数和BI生物指数对洞庭湖各样点的水质状况进行评价,总体上评价结果分别为轻污染和良好,结果表明二者具有一定的差异,结合洞庭湖各样点的综合营养状态指数可以看出,BI指数的评价更加适合洞庭湖水质评价. 相似文献
7.
赣江下游流域大型底栖动物群落结构及水质生物学评价 总被引：3，自引：1，他引：2
2009年6月(丰水期)、11月(枯水期)和2010年4月(平水期)对赣江下游流域大型底栖动物群落结构进行调查研究,共鉴定出大型底栖动物3门15科25种.结果表明,赣江下游流域大型底栖动物群落结构具有明显的时空变化.生物密度最大值(145.9±81.8 ind./m2)出现在6月,最小值(89.6±15.9 ind./m2)出现在4月;生物量的变化则相反,最大值(90.1±25.4 g/m2),出现在4月,最小值(62.9±20.9 g/m2)出现在6月;干流的生物密度在6月、11月和4月均明显高于支流,而生物量在11月低于支流.Shannon-Wiener多样性指数(H’)、Margalef丰富度指数(D)和Pielou均匀性指数(J)在6月、11月和4月的时间尺度上以及干流、支流的空间尺度上均出现明显的变化,在11月份,这3类指数均表现为最高,6月则均为最低;干流的H’和D在6月和4月均低于支流,而J在这3个时间段内则均是支流高于干流,表明支流大型底栖动物的群落结构较干流更为多样、均匀和稳定.H’和D的结果表明赣江下游流域水质均受到不同程度的污染,其中干流的污染程度较支流更为严重. 相似文献
8.
湖北省三道河水库底栖动物的初步研究 总被引：4，自引：2，他引：2
2007年8月至2008年4月,在湖北省三道河水库6个采样点调查底栖动物,共采集到底栖动物17种,其中水生昆虫11种,均为摇蚊科;寡毛类6种,均为颤蚓科,春季优势种为前突摇蚊,夏季优势种为小摇蚊、流水长跗摇蚊和前突摇蚊,秋、冬季优势种为霍甫水丝蚓,底柄动物种类数、密度和生物量随季节变化明显,种类数夏季＞冬季＞秋季＞春季,密度和生物量春季＞冬季＞秋季＞夏季,周年密度和生物量分别为366.42±102.93ind/m2和0.5649±0.1779g/m2,属贫营养型水库,现存量自坝前向库尾逐步递增,Shannon-Wiener指数、Margalef丰富度指数和Pielou均匀度指数均在夏季最高,秋季最低,4次调查中寡毛类密度均未超过1 000ind./m2,水质属轻度污染. 相似文献
9.
较系统地比较了典型草型湖泊(扁担塘)与典型藻型湖泊(后湖)底栖动物优势种类、主要类群及整个群落的周年生产量.结果表明,典型草型湖泊扁担塘底栖动物群落的周年生产量(湿重或带壳湿重)38.926g/穴m2·a雪比典型藻型湖泊后湖47.505g/穴m2·a雪为低.各类群具体情况为,后湖(藻型湖泊)的营养水平较高,更适合苏氏尾鳃蚓等耐污性种类的生长,因此寡毛类生产量较扁担塘的为高;藻型湖泊比草型湖泊更适合铜锈环棱螺等腐生螺类的生长,螺类的生产量也比草型湖泊略高;藻型湖泊摇蚊的生产量较高,原因在于藻型湖泊更适合具有较多耐污种类的摇蚊生长.但从大型底栖动物群落生产量的组成看,摇蚊、软体动物、寡毛类等三大类群所占份额相对较稳定,分别为14%-15%、77%-79%、7%-8%. 相似文献
10.
太湖霍甫水丝蚓(Limnodrilus hoffmeisteri Claparède)的时空格局 总被引：1，自引：1，他引：0
2005年1-12月对太湖霍甫水丝蚓进行了逐月调查.太湖霍甫水丝蚓年均密度和生物量分别为3273.75 ind./m2和4.697 g/m2,均在2月份达到最大值.根据体长频数分布的周年变化,推测太湖霍甫水丝蚓一年有三代.太湖霍甫水丝蚓密度和生物量在空间上表现出明显的差异性,且随季节变化较小,其高值区域均出现在太湖北部梅梁湾和竺山湾及西部河口湖区,而在其它区域的现存量均较低.分析表明太湖霍甫水丝蚓空间差异可能与营养水平、底质类型、可摄食的食物及生境的稳定性等因素有关. 相似文献
11.
Majority of shallow floodplain lake ecosystems of the middle and lower reaches of the Yangtze River (China) have gone through serious eutrophication problems over the recent past. The severe environmental deterioration accompanied by cyanobacterial blooms have become major water resource management challenges in the region. An advanced research method is urgently needed to tackle these challenges. The concept of ecological resilience address pressing questions of non-linear dynamics, threshold effects and regime shifts in shallow floodplain lakes, and help manage the ecosystem effectively. Palaeolimnological techniques are important for assessing long term resilience and associated thresholds effects of shallow lake ecosystems. However, the lack of reliable proxy methods available, the assessment of long term ecological resilience of shallow Yangtze River lake systems has become increasingly difficult. Cladocerans (water fleas) play a central role in lacustrine food webs by responding to external drivers and internal ecosystem processes in lakes. Their subfossils are well preserved and becoming one of potential proxy indicators of lake ecosystems change for a longer time scale. This study explores the potential application of subfossil cladocerans and their ephippia in assessing a long term ecological resilience and help better management strategies of lake ecosystems and water resources of the middle and lower reaches of the Yangtze River in China. 相似文献
12.
为了加强长江中游地区大型无脊椎底栖动物的研究工作,2009年3月至2010年3月,对长江中游巴河支流的胜利河毛翅目优势种的生产力和营养基础进行了为期一年的调查研究.结果表明,胜利河中主要毛翅目优势种纹石蛾的生活史为一年3代.一至四级河流中,其生物量周年平均值分别为1.77、7.80、44.82、51.55 mg/m2.采用体长频率法测算的年均生产量为7.72 mg/m2,P/B系数为13.21.利用肠内含物分析法研究了胜利河中纹石蛾的营养结构.比较一至四级河流的营养基础发现,无形态碎屑为纹石蛾最常见的食物,占肠内含物的45.22%~62.92%;而对生产量贡献率最高的多是动物组织,达52.86%~68.58%.各季节的营养基础状况也有差异,春季无形态碎屑所占比例和对生产量的贡献率较高,而夏、秋和冬季动物组织则有更高的生产量贡献率.一至四级河流的年均物质通量分别为11.83、34.76、237.52和273.17g/(m2·a).由此可见,该优势种在河流生态系统中发挥着重要作用. 相似文献
13.
Jing Guo Hua Chen Chong-Yu Xu Shenglian Guo Jiali Guo 《Stochastic Environmental Research and Risk Assessment (SERRA)》2012,26(2):157-176
Many impact studies require climate change information at a finer resolution than that provided by general circulation models
(GCMs). Therefore the outputs from GCMs have to be downscaled to obtain the finer resolution climate change scenarios. In
this study, an automated statistical downscaling (ASD) regression-based approach is proposed for predicting the daily precipitation
of 138 main meteorological stations in the Yangtze River basin for 2010–2099 by statistical downscaling of the outputs of
general circulation model (HadCM3) under A2 and B2 scenarios. After that, the spatial–temporal changes of the amount and the
extremes of predicted precipitation in the Yangtze River basin are investigated by Mann–Kendall trend test and spatial interpolation.
The results showed that: (1) the amount and the change pattern of precipitation could be reasonably simulated by ASD; (2)
the predicted annual precipitation will decrease in all sub-catchments during 2020s, while increase in all sub-catchments
of the Yangtze River Basin during 2050s and during 2080s, respectively, under A2 scenario. However, they have mix-trend in
each sub-catchment of Yangtze River basin during 2020s, but increase in all sub-catchments during 2050s and 2080s, except
for Hanjiang River region during 2080s, as far as B2 scenario is concerned; and (3) the significant increasing trend of the
precipitation intensity and maximum precipitation are mainly occurred in the northwest upper part and the middle part of the
Yangtze River basin for the whole year and summer under both climate change scenarios and the middle of 2040–2060 can be regarded
as the starting point for pattern change of precipitation maxima. 相似文献
14.
利用日本气象厅历史海温资料、NCEP/NCAR再分析资料、海表温度和降水资料,研究了1951-2010年前期西太平洋暖池（简称暖池）热含量异常与长江中下游夏季降水的关系,及其可能影响途径.结果表明,前期暖池热含量与长江中下游夏季降水存在超前2个季节的显著负相关关系,前期11-1月（即上年11月-当年1月,下同）暖池关键区（166.5°E-173.5°W,7.5°S-3.5°N）0~200 m热含量的偏低（高）对长江中下游夏季降水偏多（少）的预测有重要指示意义.前期暖池热含量异常的持续存在,及其外强迫作用激发的具有一定斜压性结构的夏季东亚-太平洋型遥相关（EAP）,可能是影响长江中下游夏季降水的主要原因.暖池热含量在前期11-1月异常偏低导致其西北侧菲律宾异常反气旋形成并维持,夏季菲律宾异常反气旋向西北方向扩展加强,东亚沿岸EAP波列形成,使得长江中下游及其以东的西北太平洋副热带地区受异常气旋控制,且长江中下游地区为北方冷空气与南方暖湿气流的交汇区.同时,对流层高层东亚沿岸亦存在位置较中低层向西北偏移的EAP波列,长江中下游及其以南地区为异常偏强高压,高层辐散与中低层辐合相配合,有利于长江中下游地区对流发展和降水增多;反之亦然. 相似文献
15.
于特枯水情年对三峡水库溶解硅和长江干流自涪陵至河口段悬浮颗粒物、溶解硅、生物硅和叶绿素a浓度等进行调查.研究表明,在平水期和汛期末,长江干流水体溶解硅和生物硅浓度和通量在其上游受大坝"滞留"效应的影响呈现沿程降低的趋势,中、下游受"两湖"和汉江等的补充作用有明显升高.在枯水年,长江干流水体生物硅浓度占活性硅(溶解硅和生物硅之和)浓度的2%~5%,显著低于平水年的比例(13%),同时也低于世界河流的平均水平(16%).三峡水库在4-12月份减少溶解硅向下游的输送通量,而在1-3月份增加溶解硅的输送通量;水库在枯水年滞留了大约3%~6%的溶解硅.三峡水库内低的初级生产水平和高的生物硅再生速率是其难以对溶解硅形成有效滞留的主要因素.大坝下游会因清水下泄产生潜在的滞留效应,不过还需要更多的数据去量化. 相似文献
16.
长江中下游湖泊大型底栖动物群落结构及多样性 总被引：4，自引：1，他引：3
2007年10月至2008年4月,对长江中下游地区四种不同类型(草型、天然养殖、施肥养殖以及城市湖泊)的10个湖泊的大型底栖动物群落结构和多样性进行研究,并分析其与水体营养状态之间的关系.研究结果表明,不同类型湖泊底栖动物的密度、生物量、多样性及特征种类均存在显著差异.草型湖泊具有最高的生物量和多样性,但密度最低,其特征种类为腹足纲动物.天然养殖湖泊生物量也较高,物种多样性处于中间水平,特征种类为河蚬、寡鳃齿吻沙蚕及苏氏尾鳃蚓.施肥养殖湖泊和城市湖泊底栖动物密度较高,并呈现出最低的物种多样性,特征种类主要是耐污能力较强的颤蚓类和摇蚊科幼虫.相关性分析表明湖泊营养状态指数与底栖动物密度呈显著正相关,而与生物量呈显著负相关,说明随着营养水平的增加,底栖动物群落逐渐被小个体的耐污种类所主导.Margalef丰富度指数及Pielou均匀度指数与营养状态指数亦呈显著负相关,反映目前长江中下游湖泊随营养水平增加底栖动物群落趋于简单化的演替趋势. 相似文献
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This paper is a review of research works concerning the nutrient transportation, transformation and exchange between water, sediment and biota in the lakes from the middle and lower reaches of the Yangtze River conducted in the context of project entitled "The Processes and Mechanism of Lake Eutrophication in Middle and Lower Reaches of Yangtze River". All the lakes from this area are shallow lakes. According to the typical lake site research, the lakes from the middle and lower reaches of Yangtze River have a higher baseline of nutrition in the history. Normally the trophic status of these lakes can be categorized into medium-trophic or eutrophic. Human activities have been enhanced during the last decades, which speed up the lake eutrophic process. Lake eutrophication control needs to reduce not only the external nutrient inputs from watershed but also the internal loading from the sediments. Investigations revealed that the lake sediments in this area are considerablly high in nutrition in which at most about 30% of phosphorus exists in the form of bio-available in the sediment. The surface sediment will exert great effects on the nutrient exchange between water-sediment interface via adsorption and release of nutrient. The nutrient release from the sediment in these shallow lakes is mainly in two ways, i.e. in the undisturbed condition the nutrient is released through diffusion created by the nutrient gradient from sediment to overlying water; whereas in disturbed condition, the nutrient release is determined by the hydrodynamic forcing intensity and the sediment resuspension. Metallic elements such as the iron, manganese and aluminium and the aerobic-anaerobic ambience will affect the release of nutrients. The disturbed release will increase the total nutrients in the water column significantly in the short period. At the beginning of sediment resuspension, the dissolved nutrient concentration will increase. This increase will be damped if the ferric oxide and aluminium are rich in sediment because of the adsorption and flocculation. This means that the lakes have capability of eliminating the nutrient loadings. Investigations for the lakes from middle and down stream of Yangtze River have suggested that most lakes have the self-cleaning capability. Dredging the control of the internal loading, therefore, is only applicable to the small lakes or undisturbed bays which normally are situated nearby the city or town and rich in organic materials in the sediment. In addition, the strong reduction condition and weak aeration of these lakes and bays make these small lakes and bays release much more bio-available nutrient and without much self-eliminating capability. Moreover, eutrophication induced algal bloom in these lakes will change the pH of water, which further induces the increase in the nutrient release. In turn, the increase in nutrient release promotes the growth of phytoplankton and results in severe algal bloom. For the heavily polluted water, research suggests that the biomass of bacteria and alkaline phosphatase activity will be higher corresponding to the higher concentration of nutrients, which accelerates the nutrient recycling between water, sediment and biota. Quick recycling of nutrient, in turn, promotes the production and biomass growth of microorganism and leads to more severe eutrophication. Further research work should focus on the nutrient transformation mechanism and the effects of microbial loop on the eutrophication. 相似文献
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近百年来长江中下游地区的浅水湖泊经历了气候变化及日益增强的人类扰动,造成了普遍的湖泊富营养化、水动力条件和水生生态系统的状态转变,水体的生态服务功能明显退化.枝角类作为一种重要的水生生物,敏感地响应于湖泊及其流域的环境变化,但目前对亚热带湖泊中的枝角类亚化石的环境指示意义,与其它古生态指标如硅藻、摇蚊等对环境变化的响应差异尚未明确.因此,本文以浅水湖泊太白湖为研究对象,结合流域历史资料和监测数据,基于沉积岩芯中枝角类群落过去百年来的期演化序列,重建了近百年来太白湖的历史环境演变过程及机制.对比硅藻及摇蚊的群落演化特征,探讨了多门类古生态指标对环境变化的响应差异.本文重点讨论了枝角类对湖泊鱼类产量指示意义及利用枝角类亚化石来重建历史环境的应用前景及不足. 相似文献
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