Macrophytes and phytobenthos as indicators of ecological status in German lakes — a contribution to the implementation of the water framework directive

A new assessment system for macrophytes and phytobenthos in German lakes according to the Water Framework Directive of the European Community is described. Based on biological, chemical and hydromorphological data from about 100 lake sites covering the main ecoregions, hydromorphological lake types and degradation forms, biocoenotic types could be defined. For developing a classification system the quality element macrophytes and phytobenthos was divided into two components: macrophytes and benthic diatoms. For macrophytes 4 and for benthic diatoms 4 lake types were identified. The benthic vegetation at reference conditions is described and degradation is characterised as deviation in benthic vegetation species composition and abundance from the reference biocoenosis. For classification in five ecological status classes, several metrics were developed and used in combination with existing indices. For a few of the described lake types further investigations are necessary before a classification can be developed.     

Volunteering in catchment management groups: Empowering the volunteer

This paper discusses one aspect of a phenomenographic study that investigates experiences of individuals who volunteer their time for a variety of catchment care groups in coastal Queensland. Data were collected through group and personal interviews, which were undertaken in 2001. Interviews took place in a number of locations along the east coast of Queensland, from Brisbane to Mossman, just north of Cairns. A number of broad conceptions emerged from the data, and this paper discusses one of these, that of empowerment. Analysis of interviews revealed that some catchment volunteers became personally empowered, and developed skills that they would not otherwise have had. Other volunteers saw catchment volunteering as a vehicle for empowerment that allowed individuals to have a say in decision making and governance of local resources. Many volunteers, however, revealed the difficulties associated with public participation processes, and described power struggles that arose within groups, and at a community level, when catchment group members wanted to be directly involved in decisions affecting their local environments. These struggles were further complicated by a chronic lack of resources. Despite these setbacks, community catchment groups can provide personal and group empowerment, resulting in a 'little voice' as opposed to none.     

Sustainable development and `warm fuzzy feelings': discourse and nature within Australian environmental imaginaries

This paper adopts the concept of `environmental imaginaries' to explore the influence of environmental discourses upon supporters of Australian environmental movements. Rather than investigate knowledge, values, attitudes or behaviour, as is often the focus of research into public environmentalism, this study analyses the presence, absence, influence and interactions of different environmental discourses at the interpersonal scale. The relative acceptability and familiarity of different environmental philosophies, with their radically different approaches to nature, has important impacts upon the political strategies, actions and directions adopted by environmental movements. Through conducting a series of ongoing discussion groups with self-identifying `environmentalists' it is found that nature is constructed predominantly through the language and concepts of sustainable development, although this discourse coexists with a number of concurrent and oppositional viewpoints. The power of sustainable development is self-sustained through the normalisation of particular languages and modes of expression. Alternative ideas and discourses are inhibited by a lack of language and familiarity and consequently disempowered and relegated to subordinate positions within discussions. The paper concludes by arguing that the lack of acceptance of alternative ecocentric ideas within the environmental community risks de-radicalising the movement and limits the diversity of political strategies and options that it could potentially adopt.     

Resident action groups in Sydney: people power or rat‐bags?

This paper presents an analysis of a neglected area of study by geographers; that of resident action groups. During the 1980s there has been a significant increase in the number of resident action groups throughout Sydney. Resident activism has influenced local planning processes, the location of noxious facilities and subsequent urban form. This has initiated important reactions by government at both the local and State levels. Urban collective activisms have been hypothesised as single‐issue, self‐serving nimby groups. However, RAGs are also empowering forces, in which women and men are introduced to the political structures and become engaged in protest and resistance that can challenge the social and spatial order. RAGs can, either singularly or cumulatively, force a re‐aligning of existing power relations, and they can necessitate changed modes of governance (or govern‐mentality).     

Power and privilege in alternative civic practices: Examining imaginaries of change and embedded rationalities in community economies

Community economies can be considered as examples of the diverse economies growing outside common capitalist logics of private accumulation and profit, seeking to bypass or reconfigure dominant global trends of societal and economic organization. Yet, these communities seem to fit quite well under a neoliberal program in which responsibilities are shifting downwards, favoring multi-level governance over State intervention and accountability. This binary character makes imperative an open and critical discussion on the development of community initiatives, including on the motivations and visions of citizens practicing alternative ethical consumption. This article explores the neoliberal rationalities embraced by community members within the imaginaries of change they frame and examines how these rationalities contribute to (re)producing neoliberal conditions and forms of governance. Our analysis builds on semi-structured interviews conducted among the members of 11 initiatives in 5 EU countries and on participant observation. We argue here that communities articulate an “alternative imaginary” of change that appears imprinted by core neoliberal rationalities around questions of individual responsibility, the role of the State, and civic participation and equity. It is an imaginary related to the construction of CBEs to by-pass existing socio-political and economic configurations. This imaginary more often than not responds to neoliberal promises of individual freedom and autonomy and seems to undermine CBEs' more radical possibilities at the same time obscuring more diverse voices of transformation.     

再论“滑坡群”——以三峡库区为例

在前人有关地质灾害的研究中,滑坡地质灾害以群体式出现的专业术语有"滑坡群"和"滑坡带"两种,但对其内涵的认识存在模糊性和局限性,缺乏层次性,多数情况下其只是对多个滑坡聚集的简称,没有体现出对地质灾害研究的指导意义。本文修正了"滑坡群"的概念,丰富了"滑坡群"的内涵,将"滑坡群"与相同的局部构造、活动构造相联系,使"滑坡群"内部的个体滑坡、相同新构造活动区域"滑坡群"之间的对比成为可能,实现了基础地质研究与灾害地质研究的有机结合。在此指导下提出了"滑坡群"评价方法,包括局部构造样式以及形成机理、局部构造与地质灾害空间演化规律、"滑坡群"内部个体滑坡对比,并建立了"滑坡群"时空演化模式,为预测滑坡破坏过程提供依据。     

桩基—非线性框剪结构相互作用体系（上）——群桩阻抗函数的求取

为研究桩基－非线性框剪结构相互作用体系的地震反应,需要求解群桩基础的动力阻抗函数。本文利用单桩阻抗和群桩动力相互作用因子计算群桩动力阻抗函数,计算并讨论了不同构形群桩阻抗函数在软、中和硬土地基中的变化规律和特点。研究表明：群桩阻抗表现出很强的频率相关性,随土体剪切波速的增大,群桩阻抗有较大幅度的增加,但土体剪切波速的变化对群桩效率（规格化阻抗函数）影响不大。     

非均质地基中群桩竖向荷载沉降关系分析

运用剪切位移法计算了桩轴向荷载传递因子。对于桩端采用线性的荷载传递函数,推导了基于弹塑性模型的单桩竖向荷载沉降的解析解。分析过程中考虑了土体强度沿深度线性变化的特性和桩土间的滑移现象,因此更符合大部分土体的实际性状。在此基础上,建立了考虑桩土滑移的桩-桩相互作用系数的计算公式,并将上述方法应用于群桩的分析,获得了群桩的荷载沉降特性。该分析方法克服了目前应用较多的弹性理论方法夸大桩土相互作用的缺点,单桩和群桩的荷载沉降曲线的分析结果和实测数据吻合,证明了该方法的合理性。     

贵州香纸沟岩溶藓类附生水生原生动物群落生态特征

岩溶藓类是一种独特的生态系统类型,维持了丰富的附生水生原生动物群落多样性。2006年11月26日至2007年1月26日, 对贵阳市香纸沟岩溶沉积环境中8种藓类附生水生原生动物群落进行了野外生态调查,采集样品和标本48份。经室内对附生水生原生动物培养、分离和鉴定, 揭示了该区岩溶藓类附生水生原生动物群落具有下述特征: ( 1)水生原生动物群落物种组成含24科26属36种。( 2)水生原生动物群落含6个功能营养群。其中,原生动物光合营养群( P群, Photosy nthetic auto tro phs) , 占总数的25% ; 细菌取食者群( B群, Bactivores detritivores) , 占总数的44. 44% ; 腐生营养类群( S群, Saprotrophs) ,占总数的2. 78% ;食藻者类群( A群, Algivores) ,占总数的11. 11% ; 非选择性杂食者群( N 群,Nonselective omnivores) , 占总数的11. 11% ;食肉者群( R群, Raptor s) ,占总数的5. 56%。( 3)根据岩溶水流、基质和藓类植物特征,划分该区附生水生原生动物生态群落为4个类型和8个亚类型。