长江洪水与生态建设

１９９８年长江流域的特大洪水带来了重大的灾难并引起全国人民的关注。文章试图对洪水的原因进行分析。１９９８年的洪水是多种因素造成的,其中既有自然因素,又有由于人类的不合理的活动,诸如滥伐森林、过牧、围湖造田等造成的。文章对生态重建提出了一系列建议,包括要对流域的土地利用和土地覆被进行综合考察和评价；在流域可持续发展的总体框架下制定生态恢复计划；生态重建工作包括对上游地区森林的严格保护,封山育林,建立防护林体系,发展非木质产业,在高海拔、干旱河谷和不宜造林的地方发展畜牧业等     

微生物浓度对SFBR工艺去除营养物的影响

采用序半连续式反应器(SequentialFed-batchReactor,简称SFBR,下同。)就不同微生物初始浓度对人工配置废水营养物去除效率的影响进行了研究。探讨了微生物初始浓度对COD、氮化合物(NH4-N和NO3-N)除去和微生物生长的影响。结果表明,当微生物初始浓度为140.4g/L时,COD有最高除去率(69.5%)。当微生物初始浓度≥46.8g/L,总氮除去率可达100%。菌体初始浓度对废水中营养物的去除有利。过高浓度的微生物生长,受营养物和供氧的限制。用一组涉及多个微生物反应的动力学模型,分析了微生物初始浓度对同时去除碳、氮化合物效率和微生物生长的影响。     

塿土中可给态镍浸提方法的研究

在前人工作的基础上,应用主成分分析、逐步回归分析和通径分析的方法,提出了(土娄)土中可给态镍的浸提方法及影响可给态镍的土壤性质.结果表明,DTPA浸提法可作为(土娄)土中可给态镍的浸提方法,铁锰氧化物结合态镍是(土娄)土可给镍的主要来源.碳酸盐结合态镍和有机质结合态镍是(土娄)土可给镍的潜在来源.它们在调控可给态镍的储量上起着重要作用.影响(土娄)土可给态镍最重要的土壤性质是pH和E_h7.     

稻田生态系统气体调节功能及其价值

论文以2002年在上海五四农场稻田生态系统田间实验为基础,运用造林成本法、碳税法和工业制氧法对稻田生态系统气体调节功能及其价值进行研究。研究表明:①稻田生态系统O2释放物理量变化范围为16518～38517kg·hm-2,其价值量也有相同的变化趋势,变化范围是6217～11873元·hm-2;②稻田生态系统对温室气体(CO2、N2O和CH4)调节基本上起着抑制作用,而不是促进作用,在水稻生育期内,稻田温室气体调节物理量的变化范围为-997～2787kgCO2-C·hm-2,价值量变化范围为-751～2098元·hm-2;③稻田生态系统气体调节功能的综合价值变化范围为5467～12842元·hm-2。可见,除了粮食生产和提供秸秆外,农田生态系统还为人类社会提供包括气体调节、养分转化、供观赏的景观等在内的服务功能,共同为人类福利服务。     

不同营养程度湖泊中细菌群落组成及其分子生态网络特征

长江中下游地区是我国淡水湖泊的主要集中区，随着社会和经济的快速发展，该地区绝大部分湖泊正处于富营养状态.作为湖泊生态系统中的分解者和生产者，细菌群落在维持物质循环和能量流动中扮演着极为重要的角色，然而其组成及种间关系对富营养化过程的响应机制仍不明确.利用16S rDNA测序技术和分子生态网络技术探讨了长江中下游10个湖泊水体中细菌群落的组成、结构及其网络拓扑关系等特征.结果表明:①根据湖泊水体的富营养化指数，长江中下游地区的湖泊可分为中度富营养湖泊和重度富营养湖泊两种，并且这两种湖泊中细菌群落的α多样性均无显著性差异.②在这两种湖泊中细菌群落的优势类群基本一致，如在纲水平上均以Actinobacteria、Acidimicrobiia、Sphingobacteriia和Betaproteobacteria为主，在属水平上均以Hgcl_clade和CL500-29_marine-group为主.然而，与丰富种亚群落相反，稀有种亚群落在这两种湖泊中具有显著的区别.③中度富营养湖泊中细菌群落生态网络的节点和边的数量均小于重度富营养湖泊，并且前者网络具有更多的物种协作关系，其网络的中心性也显著大于后者.研究显示，湖泊富营养化的加剧使得水体中细菌群落的组成，尤其是稀有种亚群落发生了显著的演替，并且明显地削弱了细菌群落物种之间的协作关系.      

The emergence of global environmental awareness

An effective plan for global ecosystem management must be developed in the next 10 or 20 years. Awareness of the need has recently emerged, but still no integrated resource management system is universally accepted. A fragmented management approach has not been effective. Any successful course of action must be based on three assumptions: (1) that science can determine how ecosystems function, (2) once this is known, the social/political system will be able to protect ecosystems to the extent needed for the survival of human society, and (3) reality will take precedence over political expediency because Mother Nature cannot be fooled. This discussion focuses on the transition from awareness to taking effective action.     

Changes of Cu, Zn, and Ni chemical speciation in sewage sludge co-composted with sodium sulfide and lime

A batch composting study was performed to evaluate the feasibility of co-composting sewage sludge with sodium sulfide and lime （SSL） mixture （Na2S/CaO= 1：1）, aiming at reducing the availability of heavy metals in the sludge compost. Sewage sludge with sawdust as a bulking agent was amended with SSL at 3% （w/w, dw）, and composted for 15 d in laboratory batch reactors. The four stages of the Tessier sequential extraction method was employed to investigate changes in heavy metal fractions of Cu, Zn, and Ni in sewage sludge composted with SSL. For all the three metals, the mobile fractions, such as, exchangeable and carbonate bound were mainly transformed into low availability fractions （organic matter and sulfide, Fe-Mn oxides bound and residual forms）, and the addition of SSL enhanced this transformation. Therefore, SSL is a suitable material to co-compost with sewage sludge to reduce the availability of heavy metals. According to the cabbage seed germination test, a SSL amendment of ≤3% （w/w, dw） is recommended to co-compost with sewage sludge.     

广西环江尾矿重金属形态及其潜在迁移能力分析

以广西环江地区某尾矿库3个区域的尾矿样品为研究对象,在化学成分和矿物成分分析的基础上,运用Dold七步分级化学提取法,研究了Zn,Cd,Pb,As,Sb和Ni 6种重金属的赋存形态特征,并分析了其潜在迁移能力。结果表明,3个区域的尾矿样品均为碳酸盐型金属硫化物尾矿,样品中Zn和Pb的质量浓度较高(分别达4 119.9 mg/kg和3 375.1 mg/kg),Cd和Ni的质量浓度相对较低,As和Sb的质量浓度差别较大(可达191.5 mg/kg和86.5 mg/kg)。形态分析结果表明,Zn和As的迁移性较强,且具有一定的环境风险,Pb,Cd,Sb和Ni相对较稳定。     

CRITICAL ELEMENTS IN DESCRIBING AND UNDERSTANDING OUR NATION'S AQUATIC RESOURCES1

ABSTRACT: Despite spending $115 billion per year on environmental actions in the United States, we have only a limited ability to describe the effectiveness of these expenditures. Moreover, after decades of such investments, we cannot accurately describe status and trends in the nation's aquatic ecosystems or even those in specific regions. Why? This situation has arisen in part because we have excluded the fundamental principles of probability designs that are widely used in other fields and we have often ignored direct measures of biota, the subjects of greatest concern. To demonstrate the results of ignoring these powerful statistical and biological tools, we present four case studies. These studies compare estimates of aquatic resource status derived from using (1) a probability-based study design, often with biological measures of condition; and (2) a nonstatistical study design, often using chemical surrogates. In three of the four cases, the results derived from the nonstatistical perspective underestimate the degree of biological degradation.     

ADDITION OF SPURS TO STONE TOE PROTECTION FOR WARMWATER FISH HABITAT REHABILITATION1

ABSTRACT: Longitudinal stone toe is one of the most reliable and economically attractive approaches for stabilizing eroding banks in incised channels. However, aquatic habitat provided by stone toe is inferior to that provided by spur dikes. In order to test a design that combined features of stone toe and spurs, eleven stone spurs were placed perpendicular to 170 m of existing stone toe in Goodwin Creek, Mississippi, and willow posts were planted in the sandbar on the opposite bank. Response was evaluated by monitoring fish and habitats in the treated reach and an adjacent comparison reach (willow post planting and standard toe without spurs) for four years. Furthermore, physical habitats within the treated reach were compared with seven reaches protected with standard toe on a single date three years after construction. Overall results indicated that spur addition resulted in modest increases in baseflow stony bankline, water width and pool habitat availability, but had only local effects on depth. These relatively small changes in physical habitat were exaggerated seasonally by beaver dams that appeared during periods of prolonged low flow in late Summer and Autumn. Physical changes were accompanied by shifts in fish species composition away from a run-dwelling assemblage dominated by large numbers of cyprinids and immature centrarchids toward an assemblage containing fewer and larger centrarchids. Biological responses were at least partially due to the effects of temporary beaver dams.