洞庭湖垸外灾害风险区湖洲高效生态农业模式研究

为了协调好防灾减灾与湖洲农业综合开发的关系,运用灾害学和循环经济学以及农业、林业、牧业、水产、生态、系统工程等科学交叉的理论与方法,将灾害防控技术体系、农业生产方式与高效生态农业结构的优化机理融为一体,设计了湖草洲畜、禽、鱼一体化开发的灭螺治鼠防洪技术集成模式,荻芦洲荻、芦、林、牧、农一体化开发的灭螺治鼠抗洪技术集成模式。并分别在典型区域进行了示范,试验表明：与传统农业生方式相比,生态、经济、社会三大效益十分显著。同时致力于湖洲农业产业化,认为在建设好优势农产品生产基地的基础上,大力发展与之相配套的产品加工等商品服务体系和市场体系,促进荻、芦、林、牧等产品精、深加工,延伸产业链,提高产品附加值,从整体上提高湖洲高效生态农业模式的综合效益,使之成为湖区农业经济的新增长点。     

A physical-microbial food web coupled model to study the evolution of the ecological functioning of a new reservoir after its flooding (Sep,Puy de Dôme)

The aim of this paper is to understand the temporal changes in planktonic populations and to highlight some important factors that control the biological functioning and evolution of a recently flooded reservoir, the Sep reservoir (Massif Central, France). To achieve this objective, a 1D vertical coupled physical–biological model was used and developed. It couples relevant physical processes (dispersion, advection and convection) with biological processes taking into account the complexity of interactions within the microbial food web, including the conventional grazing food chain with a microbial loop.     

Sequential polyandry affords post-mating sexual selection in the mouths of cichlid females

Females mating with multiple males may obtain direct benefits such as nuptial gifts or paternal care or indirect (i.e. genetic) benefits resulting in higher-quality offspring. While direct benefits are easily identified, it is difficult to determine indirect benefits, and it is hence largely unclear how they are obtained. This is particularly true in species with external fertilisation, where females seem to have little control over fertilisation. In cichlids, most maternal mouthbrooders show sequential multiple mating, where females visit several males for egg deposition. Genetic data revealed that multiple paternity of eggs and young in the mouth of females is common, but behavioural data of female spawning decisions are missing. Here, we test four hypotheses to explain female multiple mating in the maternally mouthbrooding cichlid, Ophthalmotilapia ventralis: (1) fertilisation insurance, (2) genetic bet-hedging, (3) female choice and (4) ‘sperm shopping’ (i.e. induction of sperm competition resulting in sexually selected sperm). Detailed observations of spawning behaviour in the field combined with histological analyses of the male reproductive organs suggest that fertilisation insurance, genetic bet-hedging and pre-mating female choice are unlikely to explain the sequential female multiple mating in O. ventralis. Instead, cryptic female choice by sperm shopping, i.e. post-mating sexual selection, is most compatible with our data and might be the major ultimate cause of multiple mating in females of this species and of mouthbrooding cichlids with maternal care in general. Our study provides new insight into ultimate causes of sequential polyandry in species with external fertilisation, as hitherto post-mating sexual selection by cryptic female choice has been assumed to be incompatible with external fertilisation mechanisms except by components of the ovarian fluid.     

Field experiment on biological contact oxidation process to treat polluted river water in the Dianchi Lake watershed

In this study two types of biological contact oxidation processes (BCOP), a step-feed (SBCOP) unit and an inter-recycle (IBCOP) unit, were designed to investigate the treatment of heavily polluted river water. The Daqing River, which is the largest pollutant contributor to the Dianchi Lake, one of the most eutrophic freshwater lakes in China, was taken for the case study. It was found that the SBCOP had higher adaptability and better performance in the reduction of COD, TN, and TP, which made it applicable for the treatment of polluted river water entering the Dianchi Lake. Nitrification rate was observed to be greatly affected by the influent temperature. During each season, the nitrification in the SBCOP was higher than that in the IBCOP. TN removal efficiency in the SBCOP was higher than that in the IBCOP during the winter and spring but poorer during the summer, possibly due to the inhibition of denitrification by higher dissolved oxygen level in the summer. Moreover, symbiotic algaebacteria growth may be conducive to the removal of pollutants.     

滴水湖水系中氮的污染特征及其影响因子

为探讨滴水湖水系各形态氮的污染特征、不同水体间的各形态氮对比特征、滴水湖水体各形态氮与环境因子的关系, 2013年春季,在上海市最大人工湖水系采集表层水样品28个、沉积物样品22个,测定各形态氮及总氮含量,并通过模拟实验着重探讨滴水湖水体盐度对沉积物向上覆水体释放NH3-N、NO3--N的影响.结果显示,滴水湖水体各氮污染水平较高,表层水体氮的空间差异性相对沉积物中氮的差异性较小.滴水湖水体无机氮以NO3--N为主,沉积物中氮以有机氮为主.周围水系含氮量较高,其中引入水源氮是滴水湖水体中氮的主要来源之一.盐度模拟实验显示,随着上覆水体盐度的增大,底泥中NO3--N的释放量会增加并趋于平衡,NH3-N的释放量则有降低并趋于稳定的趋势.     

环太湖主要河流氮素组成特征及来源

以2012年太湖20条主要环湖河流中氮素的逐月调查数据为依据,探讨了河水中氮素的含量、形态组成和季节性分布规律,旨在为进一步实施入湖河流小流域的污染治理提供依据. 结果表明,太湖20条环湖河流的ρ(TN)平均值为2.53~6.31 mg/L,鉴于太湖水体中ρ(TN)多年来居高难下,水质类别主要由ρ(TN)决定,因此按ρ(TN)年均值,将环湖20条河流分为重度、中度和轻度污染3类. DIN(溶解态无机氮)是氮素的主要存在形式,ρ(DIN)平均占ρ(TN)的72%以上. 其中,重度和中度污染河流中ρ(NH₃-N)和ρ(NO₃--N)各占ρ(DIN)的约50%,轻度污染河流则以NO₃--N为主,ρ(NO₃--N)占ρ(DIN)的60%以上. 除个别河流外,重度和中度污染河流水体中非汛期(11月—翌年4月)ρ(TN)、ρ(NH₃-N)和ρ(NO₃--N)普遍高于汛期(5—10月),并且汛期和非汛期差异显著. 这可能与非汛期的水温较低并且污水处理厂及湿地等生态系统的氮素去除率低于汛期有关,此外,也说明点源污染占主要地位;轻度污染河流中ρ(NH₃-N)在汛期和非汛期差异不显著,说明点源和非点源负荷相当. 重度和中度污染河流应重点针对点源污染开展治理;轻度污染河流应将点源、面源污染协同治理,以利于进一步改善水质.      

巢湖东部沉积硅藻组合记录的水环境变化

对巢湖东部湖心31 cm深的沉积岩芯进行放射性核素定年和化石硅藻分析,根据硅藻属种组合的变化反演了近150 a来巢湖东部水环境变化历史. 结果表明,巢湖东部水环境变化经历了2个主要阶段:①1827—2000年以Aulacoseira granulata占优势,但1970年其含量(以数量所占比例计)出现一明显谷值(22.4%),同期附生和底栖类硅藻频繁出现,反映了水动力条件减弱后又增强的趋势;该阶段水生植被较为发育,水体维持中营养状态.②2000年至今,以A. granulata和耐营养属种(A. alpigena、Cyclostephanos dubius)为优势组合,附生和底栖类硅藻含量显著减少,表明生活污水的大量排放导致湖区急剧富营养化; Hill多样性指数在2000年后显著下降,表明在该阶段水生生态系统发生退化.      

“十二五”太湖富营养化控制与治理研究思路及重点

在总结“十一五”太湖富营养化治理成效、存在问题的基础上,提出“十二五”期间水体污染控制与治理科技重大专项太湖富营养化控制与治理项目的总体设计思路. 项目以综合示范区水质改善为目标,重点研发园区化乡镇企业工业废水中难降解含氮、磷有机物的深度削减技术,农田种植业和农村分散式生活污水的控源减排技术,“湖荡湿地-入湖河流-湖滨缓冲带”为一体的生态拦截与修复技术;以湖泊水生态安全保障为目标,研发湖泛与水华灾害应急处置技术及建立水资源优化调度决策平台. 选择太湖流域重污染型竺山湾小流域、面源污染主控型苕溪小流域和城市化型太湖新城三大典型综合示范区,通过控源减排和生态修复关键技术的研发、集成和综合实施,实现综合示范区污染负荷得到有效控制、示范区水环境质量得到改善和规模化蓝藻水华发生得到有效控制的目标.      

论滇池海口闸择址重建的必要性及闸址比选

分析海口闸既有建筑物及设施的现状,从消除原水闸安全隐患,提高水位调控和泄洪除涝安全可靠性,为滇池水污染治理和水资源调度提供顺畅通道,为下游工农业用水和生态需水提供保障,提升海口河周边环境景观,保护历史建筑物等方面论述了择址重建海口闸的必要性,并根据地形、工程规模、控制范围、动拆迁量、工程地质、总体布置、工程施工、运行管理、总投资等论证比选了可行的闸址方案。     

太湖重污染湖区和水源地水质概况及藻毒素污染环境风险

近年来太湖流域局部水质状况有所改善,但太湖藻型生境条件还未根本改变,水污染防治任务依然艰巨。确保太湖湖体水质稳定达标,尤其是加强对太湖重点湖区和水源地重点污染物的调查研究十分重要。在此背景下,本文调研了太湖重点湖区和水源地水质概况、藻毒素污染时空分布特征、环境影响因子和迁移转化规律,并总结了藻毒素的环境和健康风险研究的最新进展,指出了太湖西部湖区和饮用水源地的主要环境风险,以及未来太湖藻毒素污染相关研究需解决的关键技术问题,以期为促进太湖流域重点污染物的控制和治理,确保太湖饮用水源地安全提供有益借鉴。