固城湖生物资源现状及近20年间的变化趋势

1999年对固城湖渔业生物资源进行了周年调查，结合1981年4月至1982年3月、1987年6月至1988年5月的2次调查资料，比较分析了固城湖生物资源的动态。研究结果表明，从1981年至1999年近20a间，固城湖浮游植物数量增加44．8倍，生物量增加40．6倍，生物多样性减少。浮游动物数量较20世纪80年代下降约50％，生物量高于80年代初期，低于80年代后期。底栖动物生物量下降，其中瓣鳃类、腹足类生物量下降明显，而寡毛类和摇蚊幼虫等数量与生物量增长显著。固城湖水生植物演替剧烈，水生植物群落结构发生了重大变化，已由苦草、轮叶黑藻群落演变为微齿眼子菜、菹草群落，渔业利用价值下降。每年大量水草腐烂沉积，使固城湖水质呈现不断下降趋势。指出加强对固城湖生物资源的泖控和综合利用，是固城湖生态保护和建设的关键。     

固城湖生物资源潜力及其生态渔业探讨

根据 1999年对固城湖生物资源的周年综合调查 ,推算出固城湖的生物资源可供养鱼虾蟹能力在 65～ 75万kg ,其中河蟹产量可达 2 .5万kg。分析了固城湖近年河蟹产量不高的原因并提出解决办法。为保证固城湖作为饮用水源区等多重功能的发挥 ,提出了固城湖主要生态功能区划和污染负荷量计算模型及渔业生态对策     

固城湖生物资源潜力及其生态渔业探讨

根据1999年对固城湖生物资源的周年综合调查，推算出固城湖的生物资源可供养鱼虾蟹能力在65-75万kg，其中河蟹产量可达2.5万kg。分析了固城湖近年河蟹产量不高的原因并提出解决办法。为保证固城湖作为饮用水源区等多重功能的发挥，提出了固城湖主要生态功能区划和污染负荷量计算模型及渔业生态对策。     

山东南四湖摇蚊幼虫群落结构及其对富营养化过程的指示

2010年7月至2011年4月对南四湖摇蚊幼虫群落结构进行了季度调查.共采集到12种摇蚊幼虫,平均密度和生物量分别为(861±701)ind/m2和(6.39±5.12)g/m2.优势种红裸须摇蚊(Propsilocerusi akamusi)和羽摇蚊(Chironomusplumosus)的密度以及生物量分别占总密度和总生物量的97.1%和99.1%,但红裸须摇蚊的密度和生物量显著高于羽摇蚊,分别是羽摇蚊的18.5倍和10.7倍.从水平分布看,红裸须摇蚊在上级湖的密度明显高于下级湖,羽摇蚊则呈全湖性分布,但密度较低.与历史资料相比,南四湖摇蚊幼虫群落发生了显著变化,摇蚊幼虫的平均密度由20世纪80年代初期的88 ind/m2增加到目前的861 ind/m2,优势种由20世纪80年代的羽摇蚊演变为当前的红裸须摇蚊,并且红裸须摇蚊的密度显著升高,这表明南四湖的富营养化趋势加剧.     

南京固城湖的水生生物资源及其合理利用

作者介绍了固城湖1987年6月—1988年7月调查所获各种水生生物的种类、数量和生物量等,并估算了该湖养殖鱼类的鱼产潜力及放养量。如全湖放足18×10~5尾,并满足各种鱼类的生长条件,除现有750t鱼产量外,还可增产850t鱼。本文为科学管理固城湖提供了一系列实用数据,同时还对该湖的资源合理利用和保护提出了可行性建议。     

鄂尔多斯高原本氏针茅与油蒿群落过渡过程中的植被动态

灌木入侵对草原生态系统结构和功能产生了严重影响,了解其植被动态对草地灌丛化的控制和恢复具有重要意义.在鄂尔多斯高原选取本氏针茅向油蒿群落过渡过程中不同演替阶段的代表性群落类型,采用样方法、刈割法和根钻法,对不同群落的盖度、密度、生物量、凋落物、根系以及物种多样性进行调查和分析.结果表明:从本氏针茅向油蒿群落过渡的过程中,(1)演替阶段经历了本氏针茅群落、本氏针茅+糙隐子草群落、本氏针茅+油蒿群落、油蒿+糙隐子草群落、油蒿+达乌里胡枝子群落、油蒿群落6个群落类型.(2)群落盖度呈现先下降后上升,总密度先下降后升高再下降的趋势,地上、地下生物量及总生物量和凋落物干重在演替过程中总体呈上升趋势.(3)本氏针茅的盖度、密度、生物量和重要值逐渐下降,油蒿则相反.(4)随土层深度的增加,群落内植物根系干重总体上呈下降的趋势.根系干重在0-30 cm土层较为集中,整个演替阶段油蒿群落根系干重分布出现先升高后下降趋势,到第VI阶段根系分布深度可达80-90 cm.(5)物种丰富度指数、Simpson优势度指数、Shannon-Winner多样性指数和Pielou均匀度指数均呈现先升高后下降的趋势.因此,鄂尔多斯高原草地灌丛化较为严重,尽管中度灌丛化阶段群落的盖度、生物量和生物多样性较高,但由于灌木入侵后整个演替阶段盖度、密度、物种多样性等明显下降,草原生态系统的可利用性降低,应将灌丛化草地恢复为本氏针茅为主的草地.     

菹草生物量控制对群落中沉水植物生长及水质的影响

沉生植物对维护和提高湖泊生态系统的生物多样性和稳定性,控制湖泊富营养化具有重要生态价值。对于可在水面形成致密冠层的沉水植物,生物量过大时可能会对水体功能产生不利的影响。实验通过对菹草(Potamogeton crispus)+金鱼藻(Ceratophyllum demersum)群落中菹草在春季暴发时采取不同菹草收割强度(100%、80%、60%、40%、20%和0%的收割)进行生物量控制。每种收割处理均在底泥厚度为15 cm,水深为110 cm独立实验池中(4 m长×2 m宽×2.5 m深)进行。实验研究生物量调控对冬季种菹草与春季种金鱼藻交替及水质的影响,探讨群落中菹草的最佳生物量控制强度,为草型湖泊进行沉水植物生态管理提供依据。结果表明:在40%、20%和0%(未收割)菹草收割强度处理下菹草容易产生断枝并且整株上浮,更高强度的收割减小了植株受到的浮力,促进了群落中菹草和金鱼藻的生长,并延长了菹草的生命周期,推迟了菹草的上浮时间。菹草遮光效应在一定程度上促进了金鱼藻的生长,中等偏高强度的菹草收割使得菹草和金鱼藻均处在较高的生物量水平,维持了群落的稳定性。在菹草生长期对其进行60%~80%收割可维持水体营养盐在较低的水平,并能实现冬季种沉水植物菹草与春季种沉水植物金鱼藻在群落中有效交替,可缓解存留菹草衰亡给水质带来的不利影响,强化沉水植物群落的水质净化功能。     

单种和多种群落湿地对污水的净化效果和植物生长生物量研究

对单种和多种植物人工湿地对污水的净化效果和植物生长生物量进行了研究.结果表明,两种湿地对有机物CODcr的净化效果差异不明显,但多种群落湿地对TP的净化效果优于单种群落湿地,而单种群落湿地对TN的净化效果又强于多种群落湿地.风车草在单种群落里生长旺盛,而在多种群落里生长稍差,单种群落的群落覆盖度明显高于多种群落的群落覆盖度;单种群落地上部分生物量为2395.6g/m2,比多种群落的地上部分生物量多1倍强,而多种群落的地下部分生物量为688.0g/m2,比单种群落的地下部分生物量多80%强;植物根系主要分布在0～5cm表层,该层根系生物量占根系总生物量的60%强.图1表2参12     

固城湖及其出入湖河道水质时空分布差异与历年变化趋势分析

于2012年7月至2013年7月采集固城湖及其出入湖河道水样,测定水体理化特征指标,探讨固城湖水质时空分布差异,并根据2001—2012年水质监测数据,利用PWQTrend 2010软件分析近年来固城湖及官溪河的水质变化趋势。结果表明:固城湖大湖区、港口河和漆桥河水质较好,丰水期处于轻度富营养化状态;小湖区、养殖区排污口、官溪河和胥河受纳污染负荷较大,丰水期处于中度富营养状态,而枯水期大、小湖区及出入湖河道都处于中营养状态。目前水质主要受氮磷污染的影响,主要污染源为水产养殖;2001—2012年官溪河和小湖区总体上属于Ⅲ~Ⅳ类水质,大湖区则属于Ⅲ类水质,受高淳社会经济发展和环境保护措施的影响,官溪河总氮、总磷浓度呈显著下降趋势,小湖区总氮浓度,大湖区总氮、总磷浓度都呈显著上升趋势,因此合理规划养殖业发展规模和模式,减少各类污染源排放量,是保证固城湖可持续发展的必要措施。     

滆湖后生浮游动物群落结构研究

为了解滆湖浮游动物群落现状,于2009年5月至2010年3月对滆湖后生浮游动物群落结构特征和物种多样性进行调查.结果显示,滆湖后生浮游动物为100种,轮虫25属52种,枝角类12属21种,桡足类14属27种.后生浮游动物优势种主要有萼花臂尾轮虫(Brachionus calyciflorus)、角突臂尾轮虫(Brachionus angularis)、针簇多肢轮虫(Polyarthra trigla)、桡足幼体(copepodid)和长额象鼻潘(Bosmina longirostris).后生浮游动物年均密度为1572 L-1,轮虫数量占后生浮游动物总数的98.7％,后生浮游动物密度以春季为最大.后生浮游动物年均生物量为2.34 mg·L-1,生物量以夏季为最大,枝角类生物量与桡足类密度间呈极显著正相关(r=0.516,P＜0.01),轮虫生物量与桡足类生物量间呈显著负相关(r=-0.517,P＜0.05).滆湖后生浮游动物的密度和生物量随季节变化明显,各季节密度由大到小依次为春季、夏季、秋季和冬季,生物量由大到小依次为夏季、春季、秋季和冬季;后生浮游动物Shannon-Wiener多样性指数、Margalef丰富度指数和Pielou均匀度指数值表明滆湖水体处于轻-中污染状态.     

富营养化对浅水湖泊轮虫种群结构影响研究

石臼湖和固城湖是长江中下游两个浅水湖泊,富营养化问题日益突出。为探索湖泊富营养化对轮虫的影响,于2012年平水期和枯水期对这两个湖泊轮虫种群结构进行了调查,并检测水体理化因子,分析轮虫分布与水环境因子及水体富营养状况的关系。水质检测结果显示,平水期石臼湖除个别点水体综合营养状态指数（TLI）〉50为轻度富营养状态外,大多数站点TLI50,处于轻度-中度富营养化状态。水生生物调查检出轮虫35种,其中石臼湖33种,固城湖27种,平水期种类多于枯水期。出现的轮虫以臂尾轮虫（Brachionus）和异尾轮虫（Trichocerca）居多,优势种主要有螺形龟甲轮虫（Keratella cochlearis）、广生多肢轮虫（Polyarthra vulgaris）、疣毛轮虫（Trichocerca sp.）、沟痕泡轮虫（Pompholyx sulcata）、异尾轮虫属和臂尾轮虫属等。轮虫平均密度3023.19 ind·L-1,平均生物量745.72μg·L-1。现存量季节变动明显,大部分站点平水期大于枯水期。轮虫多样性指数也是平水期大于枯水期,石臼湖轮虫多样性大于固城湖。水体综合营养状态指数（TLI）与轮虫种类数和多样性成显著负相关,随着富营养化加剧,轮虫种类减少,多样性降低。典范对应分析（Canonical Correspondence Analysis,CCA）表明,影响轮虫种群分布的主要环境因子为NH4＋-N、TN、TP和CODMn。按轮虫丰度分布与水环境因子的关系排序,2次调查的24个站点可大致分成3个组。轮虫种群结构受水体富营养状态影响,每组站点的代表性种类对水体营养状态有较好的指示作用。组1的代表性种类为曲腿龟甲轮虫,指示营养级别O-β;组2代表性种类萼花臂尾轮虫,指示的营养级别为β-α;组3以O营养级种类为主。     

Environmental conditions of Chilika Lake during pre and post hydrological intervention: an overview

Chilika Lake, the largest brackish water lagoon in Asia, is a prominent biodiversity hotspot along the Indian east coast. The geomorphology, water quality and biological productivity of the lake had undergone significant changes over the years under the influence of natural events and anthropogenic interventions. Decades of research have shown that the ecological changes of the lake system and its fisheries were influenced mainly by the water exchange between the lake and the sea that controls the salinity, siltation, macrophyte infestation and recruitment of marine forms. Depletion of fisheries and loss of biodiversity in 1980s and 1990s have been linked to the northward shifting of lake’s inlet and silting up of the outer channel. In order to improve the health of the lagoon and restoration of its biodiversity, a new mouth was dredged open in September 2000. Opening of the new mouth has resulted in some improvements with substantial increase in capture fishery, reduction in weed infestation, growth of seagrasses, appearance of dolphins and increase in the population of migratory birds. But, many stake holders claim that the problems associated with the lake ecology and its contribution to the socio-economic development of the stake holders still persist which could escalate in future.     

Role of the bivalveCorbicula japonica in the nitrogen cycle in a mesohaline lagoon

The effect of the bivalveCorbicula japonica on the nitrogen cycle in Lake Shinji, a mesohaline brackish lagoon in Japan, was examined quantitatively based on field surveys and laboratory experiments carried out in the summer of 1982 and 1983. The biomass of the flesh ofC. japonica comprised 97% of the total biomass of the macrozoobenthos in summer. Total biomass ofC. japonica in the lake was estimated 30 986 t fresh wt. The concentration of suspended solids immediately above the lake bottom, whereC. japonica filters the water, was 1.5 to 4 times higher than that in the surface water. In laboratory experiments, the filtration rate was 5.0 litres g dry flesh wt^-1 h^-1, the excretion rates of ammonia and of feces and pseudofeces ofC. japonica were 200×10^-6 g N g dry flesh wt^-1 h^-1 and 33.4 mg dry wt g dry flesh wt^-1 h^-1, respectively at 27°C, the average summer water temperature in the lake. From our study, we estimated thatC. japonica filters almost the same amounts of particulate organic nitrogen produced in the lake by phytoplankton and that supplied from rivers, and that it excretes 30% of filtered nitrogen as feces or pseudofeces and 18% as ammonia.     

不同底质和透明度下马来眼子菜的表型可塑性研究

马来眼子菜(Potamogeton malaianusMiq.)是目前太湖沉水植物优势种之一。文章比较分析了3种不同底质和透明度情况下马来眼子菜的生长特征,探索其在太湖不断扩展的原因及其适应性。分别选取粘土质粉砂、粉砂和下蜀黄土底质上生长的马来眼子菜进行观察试验。结果表明,这3种底质在粒度组成、营养盐和分布特征上具有显著差异。在太湖粘土质粉砂和粉砂底质上马来眼子菜的生物量比下蜀黄土底质上的马来眼子菜高,其生物量随着底质营养盐的增加而增加。马来眼子菜与觅光相关的形态指标,如高度、节间距、节数、叶数、叶长及叶面积均随着底质营养盐的增加而显著增加。马来眼子菜的冠层高度与水体的透明度呈显著负相关,表明其对剧烈变化的湖泊光环境具有很强的适应能力。马来眼子菜在不同底质上的形态可塑性是其优先占据湖泊资源成为优势种的重要原因。     

Elucidation of ecosystem attributes of an oligotrophic lake in Hokkaido,Japan, using Ecopath with Ecosim (EwE)

The fishing practices in the oligotrophic Lake Toya, Hokkaido, Japan, have profound implications in the ecosystem sustainability. The status of the sockeye salmon (Oncorhynchus nerka) population has become a serious concern among the lake managers and policy makers during the last decades. While the decline of the sockeye salmon population has been well documented in Lake Toya, there is considerable uncertainty with regards to the impact on the broader system dynamics. In this study, our objective is to address this knowledge gap by undertaking a synthesis of the Lake Toya food web using the mass-balance modeling software Ecopath with Ecosim (EwE). Our primary research question is to examine the repercussions of the declining sockeye salmon population on the trophic dynamics of the lake. Namely, we assess if there are any competing species that might have benefited from the decrease of sockeye salmon standing biomass and to what extent do these changes propagate through the Lake Toya food web? Our analysis pinpoints the critical role of the Japanese smelt (Hypomesus transpacificus nipponensis) in the system, which demonstrates a wide range of effects on several functional groups at both higher and lower trophic levels in Lake Toya. In particular, being a substantial portion of the masu salmon (Oncorhynchus masou) and adult sockeye salmon diets, the Japanese smelt has a positive impact on the top predators of the system. Amphipods, insects, and shrimp strongly benefit from the autochthonous and allochthonous organic matter in the system, while the tight coupling between phytoplankton and zooplankton seems to be particularly critical for the integrity of the Lake Toya food web. Whereas the values of the different ecosystem attributes (e.g., primary production/biomass, biomass/total throughput, system omnivory index, amount of recycled throughput, Finn's cycling index) provide evidence that Lake Toya is an immature system, we note that the internal redundancy and the system overhead estimates suggest that the lake possesses substantial reserves to overcome external perturbations. We also examined the effects of a variety of fishing policies on the biomass of masu salmon and adult sockeye salmon, which verify the belief that the adult sockeye population is quite fragile with high likelihood to collapse. Our analysis also predicts that sockeye will not rebound unless the fishing pressure exerted is substantially reduced (>50% of the reference levels used). Masu salmon seems to benefit under all the scenarios examined indicating that the intensity of the current fishing activities is significantly lower than its biomass accumulation rate in the system.     

长江水系河水氮污染

对１９９０年长江流域５７０个水文站约８０００测次数据的统计分析表明,长江干流氮污染水平自上游向下游有明显增强的趋势;相当一部分站点八十年代中期河水总氮含量比１９６０年前后增加５－１０倍;河水氮含量的年内变化不同区域有各自的特点;河水氮污染的差异与区域人口的经济发展的水平有关。氮污染促进了河水的酸化过程。     

江苏省里下河地区湖泊资源动态研究

根据 198 1年的地形图资料和 1997年的 TM资料 ,利用遥感和 GIS方法对江苏省里下河地区的大纵湖和蜈蚣湖水体信息进行了动态监测 ,发现由于围湖养殖导致两湖面积减少很快 ,滞涝库容急剧下降 ,对该区滞洪和航运带来不利影响 ,并直接影响该区社会经济的可持续发展。针对湖泊面积的减少 ,指出了保护湖泊资源和湖区经济可持续发展的相应对策 ,为该区合理利用湖泊资源提供了参考依据     

Lake phosphorus dynamics and climate warming: A mechanistic model approach

Model results in this work indicate that lakes may respond very differently to climate change depending on their physical character. A physical lake model and a mechanistic phosphorus model are combined with two temperature scenarios generated by a regional climate model (RCM) in three sites in central Sweden—Lake Erken and two basins of Lake Mälaren (Galten and Ekoln). In the phosphorus model water mixing, mineralization, diffusion and biouptake are temperature dependent. In the simulations, Lake Erken is much more sensitive to climate warming than the two basins of Lake Mälaren, and the reason is shown to be the much longer water residence time in Lake Erken (7 years), stressing the importance of internal lake processes. In Galten and Ekoln the water residence times are less than 1 year, and the effects of water temperature changes are small. In Lake Erken the concentration of epilimnetic-dissolved phosphorus is almost doubled in spring and autumn in the warmest climate scenario. Since the lake is mostly phosphorus limited, this means that the potential for phytoplankton production is almost doubled. The implication would be that in Lake Erken, and in other eutrophic lakes with long water residence times, eutrophication problems may become serious in the future, and that managers may need to take action today in order to maintain good water quality in these lakes.