喜旱莲子草在中国的入侵机理及其生物防治

喜旱莲子草为全球性恶性杂草,也是中国生物多样性国家报告中首批9种重要外来入侵植物之一.本文综述了喜旱莲子草的起源、分布以及在我国的传播扩散和危害,并分析了入侵机制.鉴于这是我国生物防治外来杂草最成功的项目,还介绍了利用昆虫天敌生物防治的过程、实践和经验,讨论了存在的问题及应对策略. 参60     

三江平原湿地植物物种空间分异规律的探讨

研究了三江平原典型湿地在地形、水分等因素制约下的植物物种空间分异规律,包括垂直分异规律和水平分异规律。首先,按照地形和水分的分异组合特点,把湿地生境分为较干燥生境、季节积水生境和常年积水生境。然后,在各个生境内采用样方法和样线法调查植物物种。调查分为20世纪70年代、80年代和2003年3个时期,范围包括三江平原的典型湿地植物群落。数据分析时采用了生境组合法。即把3个不同的生境组合成一个水分(或地形)梯度带,根据频度和多度指标筛选出主要物种,然后按照其空间位置,列出主要植物物种沿水分梯度带的分布序列。研究发现:三江平原湿地不同生境的植物物种组合和垂直分异差别明显。较干燥生境的植被类型以岛状林群落为代表,乔木、灌木和草本植物层次分明。季节性积水生境的植被类型以小叶章群落为代表,是典型的湿草甸植物群落,垂直结构不明显。常年积水生境以毛果苔草群落为代表,植物群落层次也比较明显。植物物种水平分异规律,基本上可由植物物种空间分布序列图来代表。随着地势降低,水分增多,乔、灌植物,湿草甸植物,水生草本植物在特定的空间依次出现。     

壳聚糖及其应用

壳聚糖为甲壳素脱乙酰化的产物,其应用研究已取得较大进展,并且已有相当部分进入实用阶段或商品化阶段.壳聚糖的应用面广,它在生物学、医学领域以及食品、化妆品、环保、纺织、印染、造纸等工业上均有较大的应用价值.介绍了近几年壳聚糖在生物学、医学和环保等领域的应用前景,以推动对它的深入研究和利用,从而开辟出更新、更广阔的应用领域.     

同步硝化反硝化技术研究进展

结合国内外最新研究成果,从微环境理论、生物学理论对同步硝化反硝化的产生机理进行了介绍,阐述了同步硝化反硝化技术的影响因素及其研究进展,介绍了同步硝化反硝化技术的最新应用情况,对该技术需要解决的问题及应用前景作了探讨.     

高效复合菌在木薯酒精废液处理中的应用研究

对酒精废液生物处理反应器内颗粒污泥中的微生物进行分离纯化.分离出的8株高效优势菌,初步鉴定结果:1号为皮杆菌属;2号为棒杆菌属;3号、4号为微小杆菌属;5号为乳杆菌属;6号为纤维单胞菌属;7号为丙酸杆菌属;8号为红长命菌属.对8种纯化后的菌株进行混合培养,确定了复合菌群生长最佳培养温度为37℃,最适pH值为6.8.在处理过程中投加适量葡萄糖、硝酸铵和微量元素能够提高复合菌群的处理效果.最佳添加量为:葡萄糖0.5g/L,硝酸铵1g/L,Fe2 5mg/L和Ca2 25mg/L.在日处理量100 m3的UASB生物反应器中投加该复合菌群后,木薯酒精废液的COD去除率明显提高,达到90%以上.处理系统运行稳定.     

生物标志物

生物标志物技术是常规生物检测方法的必要补充，其在环境管理，风险性评价和生态恢复方面有着较广泛的应用，该文主要介绍了相对于常规生物检定方法而言，生物标志物所具备的优点，以及常用生物标志物的类型，生物标志物在环境保护领域的应用等     

珍稀植物濒危机制及保育策略中的营养条件

首先简要论述了珍稀植物濒危的原因、濒危机制的各种理论和研究方法，包括就地保护和迁地保护两个方面的保育策略的制定与实践。然后着重从营养条件的角度对这些理论和现状进行了分析。认为濒危物种在其历史演化过程中存在的脆弱环节以及活植物迁地保护的评价标准均与营养条件密切相关，营养条件可能是某些物种濒危机制中的一个重要组成部分；营养条件方面的研究可以为保护区设立的大小提出指导性意见；珍稀植物迁地保护过程中应密切关注营养条件的影响；营养条件在一定程度上决定了对某些物种保育策略的制定；将分子生物学与植物营养学的研究方法相结合，将能成为珍稀植物濒危机制及保育策略研究中的一种有效手段。     

Honey bee foragers as sensory units of their colonies

Forager honey bees function not only as gatherers of food for their colonies, but also as sensory units shaped by natural selection to gather information regarding the location and profitability of forage sites. They transmit this information to colony members by means of waggle dances. To investigate the way bees transduce the stimulus of nectar-source profitability into the response of number of waggle runs, I performed experiments in which bees were stimulated with a sucrose solution feeder of known profitability and their dance responses were videorecorded. The results suggest that several attributes of this transduction process are adaptations to enhance a bee's effectiveness in reporting on a forage site. (1) Bees register the profitability of a nectar source not by sensing the energy gain per foraging trip or the rate of energy gain per trip, but evidently by sensing the energetic efficiency of their foraging. Perhaps this criterion of nectar-source profitability has been favored by natural selection because the foraging gains of honey bees are typically limited by energy expenditure rather than time availability. (2) There is a linear relationship between the stimulus of energetic efficiency of foraging and the response of number of waggle runs per dance. Such a simple stimulus-response function appears adequate because the range of suprathreshold stimuli (max/min ratio of about 10) is far smaller than the range of responses (max/min ratio of about 100). Although all bees show a linear stimulus-response function, there are large differences among individuals in both the response threshold and the slope of the stimulus-response function. This variation gives the colony a broader dynamic range in responding to food sources than if all bees had identical thresholds of dance response. (3) There is little or no adaptation in the dance response to a strong stimulus (tonic response). Thus each dancing bee reports on the current level of profitability of her forage site rather than the changes in its profitability. This seems appropriate since presumably it is the current profitability of a forage site, not the change in its profitability, which determines a site's attractiveness to other bees. (4) The level of forage-site quality that is the threshold for dancing is tuned by the bees in relation to forage availability. Bees operate with a lower dance threshold when forage is sparse than when it is abundant. Thus a colony utilizes input about a wide range of forage sites when food is scarce, but filters out input about low-reward sites when food is plentiful. (5) A dancing bee does not present her information in one spot within the hive but instead distributes it over much of the dance floor. Consequently, the dances for different forage sites are mixed together on the dance floor. This helps each bee following the dances to take a random sample of the dance information, which is appropriate for the foraging strategy of a honey bee colony since it is evidently designed to allocate foragers among forage sites in proportion to their profitability.     

A Geochemical and Biological Basis for Marine Sediment Quality Guidelines

This document describes a basis for the establishment of marine sediment quality guidelines for regulatory applications. It outlines a geochemical basis for identifying potential anomalies in the presence of inorganic contaminants in marine sediments and a biological or ecotoxicological basis for determining concentrations unlikely to result in adverse biological effects. These approaches are discussed in an exploratory fashion. It is intended that both approaches could be combined in a manner that takes account of sedimentary nature and composition as a conceptual and practical approach to the establishment of guidelines for regulatory applications associated with the protection of the marine environment.     

Some Guiding Concepts for Conservation Biology

Abstract: The search for generalities in ecology has often been thwarted by contingency and ecological complexity that limit the development of predictive rules. We present a set of concepts that we believe succinctly expresses some of the fundamental ideas in conservation biology. (1) Successful conservation management requires explicit goals and objectives. (2) The overall goal of biodiversity management will usually be to maintain or restore biodiversity, not to maximize species richness. (3) A holistic approach is needed to solve conservation problems. (4) Diverse approaches to management can provide diverse environmental conditions and mitigate risk. (5) Using nature's template is important for guiding conservation management, but it is not a panacea. (6) Focusing on causes not symptoms enhances efficacy and efficiency of conservation actions. (7) Every species and ecosystem is unique, to some degree. (8) Threshold responses are important but not ubiquitous. (9) Multiple stressors often exert critical effects on species and ecosystems. (10) Human values are variable and dynamic and significantly shape conservation efforts. We believe most conservation biologists will broadly agree these concepts are important. That said, an important part of the maturation of conservation biology as a discipline is constructive debate about additional or alternative concepts to those we have proposed here. Therefore, we have established a web‐based, online process for further discussion of the concepts outlined in this paper and developing additional ones.