典型化学污染物在环境中的变化及生态效应——国家自然科学基金“八·五”重大项目介绍

国家自然科学基金“八·五”重大项目——“典型化学污染物在环境中的变化及生态效应”已被批准立项,并将于1992—1995年内付诸实施。本项目研究内容涉及典型化学污染物在环境中迁移、转化及降解的化学过程;在多介质环境中的循环过程及模型;生态毒理学效应;对生态系统结构与功能的影响和预测;以及生态调控对策等五个课题。它是一项涉及环境化学、环境生态学和环境预防医学的多学科交叉的综合性研究项目。此项目科学意义重大,不仅是因为它与我国国民经济、生态环境和人体健康有着密切的关系,而且还因为它的研究将促进我国有关环境科学领域的基础和应用基础理论研究提高到一个新的水平。此外,它将为污染物的环境化学行为及生态效应的多学科,综合性研究积累方法学经验,从而为我国环保工作做出贡献。     

长白山区沟谷乌拉苔草(Carex. meyeriana)沼泽湿地水文物理效应

通过对长白山区沟谷乌拉苔草(C.meyeriana)沼泽湿地和三江平原乌拉苔草沼泽湿地土壤物理性质和乌拉苔草根系生物量的测定,对水文物理效应进行了分析,结果表明:长白山区沟谷乌拉苔草沼泽湿地的土壤孔隙度小于三江平原乌拉苔草沼泽湿地,容重和体积质量则高于三江平原乌拉苔草沼泽湿地。土壤蓄水能力低于三江平原乌拉苔草沼泽湿地;乌拉苔草发达的根系具有强大的蓄水能力,尤以根鞘的蓄水能力最强,蓄水可以占鲜质量的91.1%~93.72%,比根系蓄水能力高出2.54%~33.94%。由此得知乌拉苔草沼泽湿地的具有巨大的蓄水能力,是天然的水调节器。通过分析可知其水文物理过程对沼泽湿地对其上游河流具有调节作用,同时还可以保存上游河流生物多样性,以及严重的影响着水面以下化学过程的发生。     

Shoreline Development Drives Invasion of Phragmites australis and the Loss of Plant Diversity on New England Salt Marshes

Abstract:  The reed Phragmites australis Cav. is aggressively invading salt marshes along the Atlantic Coast of North America. We examined the interactive role of habitat alteration (i.e., shoreline development) in driving this invasion and its consequences for plant richness in New England salt marshes. We surveyed 22 salt marshes in Narragansett Bay, Rhode Island, and quantified shoreline development, Phragmites cover, soil salinity, and nitrogen availability. Shoreline development, operationally defined as removal of the woody vegetation bordering marshes, explained >90% of intermarsh variation in Phragmites cover. Shoreline development was also significantly correlated with reduced soil salinities and increased nitrogen availability, suggesting that removing woody vegetation bordering marshes increases nitrogen availability and decreases soil salinities, thus facilitating Phragmites invasion. Soil salinity (64%) and nitrogen availability (56%) alone explained a large proportion of variation in Phragmites cover, but together they explained 80% of the variation in Phragmites invasion success. Both univariate and aggregate (multidimensional scaling) analyses of plant community composition revealed that Phragmites dominance in developed salt marshes resulted in an almost three-fold decrease in plant species richness. Our findings illustrate the importance of maintaining integrity of habitat borders in conserving natural communities and provide an example of the critical role that local conservation can play in preserving these systems. In addition, our findings provide ecologists and natural resource managers with a mechanistic understanding of how human habitat alteration in one vegetation community can interact with species introductions in adjacent communities (i.e., flow-on or adjacency effects) to hasten ecosystem degradation.     

Environ indicator sensitivity to flux uncertainty in a phosphorus model of Lake Sidney Lanier, USA

Effective environmental impact assessment and management requires improved understanding of the organization and transformation of ecosystems in which independent agents are linked through an intricate network of energy, matter, and informational interactions. While advances have been made, we still lack a complete understanding of the processes that create, constrain, and sustain ecosystems. Network environ analysis (NEA) provides one approach for building novel ecosystem insights, but it is model dependent. As ecological modeling is an imprecise art, often complicated by inadequate empirical data, the utility of NEA may be limited by model uncertainty. Here, we investigate the sensitivity of NEA indicators of ecosystem growth and development to flow and storage uncertainty in a phosphorus model of Lake Sidney Lanier, USA. The indicators are total system throughflow (TST), total system storage (TSS), total boundary input (Boundary), Finn cycling index (FCI), ratio of indirect-to-direct flows (Indirect/Direct), indirect flow index (IFI), network aggradation (AGG), network homogenization (HMG), and network amplification (AMP). Our results make two primary contributions. First, they demonstrate that five of the indicators – FCI, Indirect/Direct, IFI, AGG and HMG – are relatively robust to the flow and storage uncertainty in the Lake Lanier model. This stability lets us draw robust conclusions about the Lake Lanier ecosystem organization (e.g., phosphorus flux in the lake is dominated by internal processes) in spite of uncertainties in the model. Second, we show that the majority of the indicators co-vary and that most of their common variation could be mapped onto two latent factors, which we interpret as (1) system integration and (2) boundary influences.     

蓝藻毒素的毒性及其生物富集、暴露途径和危险度评估

概述了淡水蓝藻释放的毒素，在毒性、生物富集等方面的某些研究进展，并探讨了人其与人群健康相关的主要暴露途径及危险度评估。蓝藻毒素的暴露途径主要有“皮肤接触、呼吸道吸入、血液透析、消化道摄入等。未来的研究将集中于不同暴露途径下，蓝藻毒素对人群健康效应的现场评价，并提出合理的预防措施及对其进行现场考核。     

10万m3/d污水处理厂新型稳定塘工艺技术经济分析

介绍了沙营污水处理厂稳定塘工艺的构成特点及2年来实际运行效果。效益分析表明,新型稳定塘工艺通过在厌氧塘安装弹性填料、在好氧塘增加表面曝气机,在养鱼塘放养各类鱼苗、在生态塘种植莲藕、芦苇,从而形成了人工可以控制的生物氧化过程来处理城市污水,具有基建投资省、维护管理方便、运行费用低等特点,在土地资源丰富的中小城市具有良好的应用前景。     

无公害农产品土地利用评价体系的研究

土地资源是人类生存最基本的资源，对它的利用与开发必须保持协调的可持续的发展规划。本文以无公害农产品土地利用为例，从环境的角度，构建了产地环境条件子系统、自然条件子系统、经济效益分析子系统和环境影响分析子系统以及各自包含的评价指数集。产地环境条件指标集和自然条件指标集是基于现状的，采用结果指标表达；针对布局规划，环境影响分析和经济效益分析是一种预测评价，对其指标集的构建采用了过程指标的设计。     

Effects of main range and strength factors on change of COD in a shallow lake 

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Contaminants and their effects on estuarine and coastal organisms in the United Kingdom in the late twentieth century

The biological effects of contaminants in British estuaries and coastal waters have been studied for over 100 years. Until the 1970s. the major pollution impact on estuarine organisms was probably caused by poorly treated sewage which led to severe oxygen deficits and consequent asphyxiation of many water-breathers. However, since the introduction of improved sewage treatment in the last 30 years, a number of continuing impacts have come to light which represent true toxic effects of micro-contaminants. Sublethal changes observed in various bioassays and biomarkers are widespread in both fish and invertebrates, and in the most urbanised and industrialised estuaries, these effects are probably having impacts at the population and community levels. For example, there is good evidence to show that tributyltin from some antifouling paints has not only affected the sexuality and reproductive success of individual estuarine and coastal molluscs, but has also damaged some benthic communities of which molluscs are but a part. Although there are data to show that some contaminant concentrations are now declining, we do not yet have enough data in most cases to decide whether organisms have also begun to recover. This paper reviews the entire field of contaminant effects in UK estuarine and marine waters, focusing especially on the years 1985-2000, and makes some recommendations for future research and monitoring programmes.     

1,2,4-三氯苯对3种海洋微藻的毒性效应

1,2,4-三氯苯(1,2种,4-TCB)是环境中普遍存在的持久性有机污染物之一,而1,2,4-TCB对藻类的毒性作用报道很少。以1,2,4-TCB处理后,3种海洋微藻(金藻Isochrysis Zhanjiangensis、角毛藻Platymonas Subcordiformis和扁藻Chaetoceros miielleri)的生长状况、蛋白质质量分数和叶绿素质量分数的改变来检测1,2,4-TCB对海洋微藻的毒性效应。结果表明:1,2,4-TCB对3种海洋微藻的生长均有一定的抑制作用,该效应表现出一定的浓度和时间依赖性;1,2,4-TCB处理4d后,3种海洋微藻细胞蛋白质质量分数和叶绿素质量分数下降,呈现一定的浓度—效应关系,这表明1,2,4-TCB对3种海洋微藻产生毒害效应,其作用机制可能与藻类光合作用功能降低和蛋白质功能受损有关。1,2,4-TCB在一定程度上降低了藻类饵料的利用价值,而且对食物链下游生物具有潜在的危害性。