Collecting data in artisanal and small-scale mining communities: Measuring progress towards more sustainable livelihoods

This short note discusses methodological obstacles to the collection of microeconomic data in artisanal and small-scale mining communities. International donor organizations are supporting policy efforts that enhance the contribution to poverty alleviation of this mining subsector. The design and evaluation of such policy interventions require data on income, expenditure, investment, and savings in mining households and communities. These data are difficult to come by. Incomes are variable; migrants may work far from home; miners often work informally and sometimes illegally; mining populations and communities are heterogeneous and transient; and miners have many reasons to distort information. Legalization and organization of miners in cooperatives would facilitate documentation and research. These processes, however, are beyond the control of the typical policy consultant or donor organization. On their part, these parties can adopt an alternative model of research. This model involves the community in project development, data collection, and monitoring. It emphasizes continuity, cultural diversity, trust building and learning. The data thus collected should provide a firm basis for programmes that promote more sustainable livelihoods in artisanal and small-scale mining communities.     

中国海岛潮下带大型底栖动物时空分布特征

利用中国近海海洋综合调查与评价(908)专项生物调查数据,从海岛类型、地理分布等方面考虑,选取26个具代表性的中国海岛,对海岛潮下带大型底栖动物群落结构的时空分布特征进行分析研究.结果表明:26个海岛潮下带大型底栖动物共鉴定767种,各海岛底栖动物种类组成均以多毛类、软体动物和甲壳动物为主,棘皮动物所占比例较小;物种数在各海岛间差别较大,在空间分布上有较明显的北低南高特点;在季节分布上,海岛潮下带大型底栖动物物种数、栖息密度和Shannon-Wiener指数(H’)都表现出春季>夏季>冬季>秋季的特点,而生物量则表现出秋季>春季>夏季>冬季的特点;受人类活动影响较强烈的长三角地区海岛、近岸岛及河口岛潮下带大型底栖动物物种数及多样性指数明显低于其他海岛,说明目前中国海岛潮下带大型底栖动物群落结构已受人类活动的明显干扰.     

基于GIS的小城镇洪灾淹没分析与应急决策系统

近年来,将GIS技术与水文模型相结合,再根据数字高程模型DEM预测、模拟显示洪水淹没区,并进行灾害评估,已成为GIS应用和水利领域一个研究热点。笔者介绍了利用GIS技术建立的小城镇洪灾淹没分析与应急决策系统的构架、数据库的建设及其实现的功能等内容。该系统解决了一系列关键技术:小城镇空间数据库的建库技术及三维可视化、洪水淹没范围的确定以及洪水淹没实时动态演示等,能够对洪水灾害及其损失进行分析预测,对洪水灾情进行快速评估,是小城镇政府部门科学地制定防洪和减灾对策,迅速有效地采取抗洪救灾措施的保障手段。该系统适合我国现有国情,有利于维护小城镇社会经济持续稳定发展,具有很强的现实意义。     

Nutrient fluxes at the landscape level and the R* rule

Nutrient cycling in terrestrial ecosystems involves not only the vertical recycling of nutrients at specific locations in space, but also biologically driven horizontal fluxes between different areas of the landscape. This latter process can result in net accumulation of nutrients in some places and net losses in others. We examined the effects of such nutrient-concentrating fluxes on the R* rule, which predicts that the species that can survive in steady state at the lowest level of limiting resource, R*, can exclude all competing species. To study the R* rule in this context, we used a literature model of plant growth and nutrient cycling in which both nutrients and light may limit growth, with plants allocating carbon and nutrients between foliage and roots according to different strategies. We incorporated the assumption that biological processes may concentrate nutrients in some parts of the landscape. We assumed further that these processes draw nutrients from outside the zone of local recycling at a rate proportional to the local biomass density. Analysis showed that at sites where there is a sufficient biomass-dependent accumulation of nutrients, the plant species with the highest biomass production rates (roughly corresponding to the best competitors) do not reduce locally available nutrients to a minimum concentration level (that is, minimum R*), as expected from the R* rule, but instead maximize local nutrient concentration. These new results require broadening of our understanding of the relationships between nutrients and vegetation competition on the landscape level. The R* rule is replaced by a more complex criterion that varies across a landscape and reduces to the R* rule only under certain limiting conditions.     

Persistent organochlorine pesticides,polychlorinated biphenyls,polybrominated diphenyl ethers in fish from coastal waters off Savannah,GA, USA

Contamination profiles of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were determined in six fish species from three selected regions along coastal waters off Savannah, GA, USA. Concentrations of PCBs were predominant (12–493 ng g^?1 lw) followed by PBDEs (10–337 ng g^?1 lw), OCPs such as DDTs (2.7–153 ng g^?1 lw), chlordanes (3.8–34 ng g^?1 lw), cyclodienes (<0.1–35 ng g^?1 lw), mirex (<0.1–8.6 ng g^?1 lw), γ-hexachlorocyclohexane (<0.1–1.4 ng g^?1 lw), and hexachlorobenzene (<0.1–0.68 ng g^?1 lw). The results indicated no region-specific difference in the contaminants however inter-species as well as intra-species differences were evident. Comparison of DDTs, PCBs, and PBDEs profiles in fish with those from other countries revealed that fish from coastal waters off Savannah contained relatively less concentrations of PCBs and chlorinated pesticides, while PBDE concentrations were comparable or even higher than fish samples from other regions. Polychlorinated biphenyl congeners and chlorinated pesticide tempoal trend data exhibited no increase of contamination levels. The levels of PCBs and chlorinated pesticides in fish from Savannah coastal waters were below the Food and Drug Administrations (FDA) established limits for human consumption.     

Role of inlets in geomorphic evolution of the south shore barriers of Long Island,New York,USA

A study of historical storm-induced changes along the south shore barriers of Long Island (Fire Island Inlet to Southampton), New York, USA, was undertaken in an effort to determine the relative roles of different transport processes in barrier migration. Inlets were found to have a profound effect on the barrier system, largely controlling its landward migration, based upon maps, charts, and aerial photographs from the seventeenth century to the present. Salt marshes became established principally on the broad intertidal bay shoals left by a closed or slowly migrating inlet. Inlets along this microtidal coast are now stabilized by jetties, which may have a negative effect on long-term barrier-island migration.     

Adaptation to Climate Change in Developing Countries

Adaptation to climate change is given increasing international attention as the confidence in climate change projections is getting higher. Developing countries have specific needs for adaptation due to high vulnerabilities, and they will in this way carry a great part of the global costs of climate change although the rising atmospheric greenhouse gas concentrations are mainly the responsibility of industrialized countries. This article provides a status of climate change adaptation in developing countries. An overview of observed and projected climate change is given, and recent literature on impacts, vulnerability, and adaptation are reviewed, including the emerging focus on mainstreaming of climate change and adaptation in development plans and programs. The article also serves as an introduction to the seven research articles of this special issue on climate change adaptation in developing countries. It is concluded that although many useful steps have been taken in the direction of ensuring adequate adaptation in developing countries, much work still remains to fully understand the drivers of past adaptation efforts, the need for future adaptation, and how to mainstream climate into general development policies.     

小城镇发展与环境保护

根据当前城镇化进程中存在的主要环境问题，提出了生态环境保护与可持续发展对策。     

On the evolutionary stability of female infanticide

Territoriality among female rodents may have evolved as an adaptation to intraspecific competition for resources or, alternatively, to defend pups against infanticide. In order to evaluate the latter, we analyse the conditions that allow an infanticidal strategy to invade a population of non-infanticidal females, and the circumstances under which infanticide may become an evolutionarily stable strategy (ESS). Our game theoretical analyses indicate that infanticide has to be associated with some direct (cannibalism) or indirect (reduced competition) resource benefits in order to invade a non-infanticidal population. We also expect that females will primarily kill litters of nearby neighbors, thereby removing the closest competitors while keeping costs at a low level. However, once established in a population, infanticide may be an ESS, even if females do not gain any resource benefits. This is theoretically possible if a female through infanticide can reduce the possibility that other, potentially infanticidal, females establish and/or stay close to her nest. While behavioral data indicate that these special circumstances sometimes occur, they may be too specific to apply generally to small rodents. Therefore, we expect that the evolutionary stability of infanticide often requires resource benefits, and that female infanticide in small rodents may, in fact, be a consequence rather than a cause of territoriality. Received: 27 June 1996 / Accepted after revision: 28 December 1996