Islands at a glance

Islands have many problems in common with certain continental areas. Yet, at the same time they provide a special case in development, largely owing to specific characteristics of their natural resources, their economies, and their culture. The rational management of small island ecosystems (less than 10,000 sq km, population 50,000 or less) is one of the main aspects of the multidisciplinary research project promoted by the “Man and the Biosphere” Program (MAB) of UNESCO. This article aims to shed light on some important methodological and conceptual issues confronted during almost two decades of fieldwork.     

古廖涌黑臭水体生物修复及维护试验

利用生物氧化塘、底泥生物氧化、水体生物修复和河道生态恢复等技术，对广州市古廖涌黑臭水体进行治理．结果表明，在进水流量5000～8000m^3／d的高负荷工业废水和生活污水冲量下，通过生物治理，消除了水体黑臭现象，从上游到下游，水色由暗黄逐步转为黄、黄绿；在上游不断流入污水情况下，CODcr除去率达50％以上，NH3-N除去率为70％，H2S除去率达80％以上．从2003年8月到2004年3月，河道生物多样性逐步增加，先后出现枝角类、桡足类动物和鱼类．表明对于暂时无法截污的城郊河道，可以利用废弃的鱼塘、空地等对污水进行预处理，再通过上述措施和技术进行生物治理，可取得良好治理效果．本研究为城市黑臭河道，特别是暂时无法截污的城郊河道的治理和养护提供了一套切实可行的方法．图3参18     

黄河三角洲原油污染土壤的微生物固定化修复技术

研究从原油污染土壤中驯化分离出高效石油烃降解菌系,以海藻酸钠和硅藻土复合载体将其制备成固定化菌,比较了固定化降解菌与游离菌对土壤中原油的降解率以及它们在土壤中活性与数量的变化.结果表明,土著降解菌经驯化后显示了较高的耐受性和环境适应能力,固定化降解菌产生了较同等菌量的游离菌明显高的降解优势,特别是在实验初期(20天时)...     

Atmospheric Change and Biodiversity in the Arctic

The Canadian Arctic is characterized by a high variation in landform types and there are complex interactions between land, water and the atmosphere which dramatically affect the distribution of biota. Biodiversity depends upon the intensity, predictability and scale of these interactions. Observations, as well as predictions of large-scale climate models which include ocean circulation, reveal an anomalous cooling of northeastern Canada in recent decades, in contrast to the overall significant increase in average annual temperature in the Northern Hemisphere. Predictions from models are necessary to forecast the change in the treeline in the 21st century which may lead to a major loss of tundra. The rate of change in vegetation in response to climate change is poorly understood. The treeline in central Canada, for example, is showing infilling with trees, and in some locations, northerly movement of the boundary. The presence of sea ice in Hudson Bay and other coastal areas is a major factor affecting interactions between the marine and terrestrial ecosystems. Loss of ice and therefore hunting of seals by polar bears will reduce bear and arctic fox populations within the region. In turn, this is likely to have significant effects on their herbivorous prey populations and forage plants. Further, the undersurface of sea ice is a major site for the growth of algae and marine invertebrates which in turn act as food for the marine food web. A rise in sea-level may flood coastal saltmarsh communities leading to changes in plant assemblages and a decline in foraging by geese and other consumers. The anomalous cooling in the eastern Arctic, primarily in late winter and early spring, has interrupted northern migration of breeding populations of geese and ducks and led to increased damage to vegetation in southern arctic saltmarshes as a result of foraging. It is likely that there has been a significant loss of invertebrates in those areas where the vegetation has been destroyed. Warming will have major effects on permafrost distribution and on ground-ice resulting in a major destabilization of slopes and slumping of soil, and disruption of tundra plant communities. Disruption of peat and moss surfaces lead to loss of insulation, an increase in active-layer depth and changes in drainage and plant assemblages. Increases of UV-B radiation will strongly affect vulnerable populations of both plants and animals. The indigenous peoples will face major changes in life style, edibility of food and health standards, if there is a significant warming trend. The great need is for information which is sensitive to the changes and will assist in developing an understanding of the complex interactions of the arctic biota, human populations and the physical environment.     

Habitat Change and Plant Demography: Assessing the Extinction Risk of a Formerly Common Grassland Perennial

Abstract:  An important aim of conservation biology is to understand how habitat change affects the dynamics and extinction risk of populations. We used matrix models to analyze the effect of habitat degradation on the demography of the declining perennial plant Trifolium montanum in 9 calcareous grasslands in Germany over 4 years and experimentally tested the effect of grassland management. Finite population growth rates (λ) decreased with light competition, measured as leaf-area index above T. montanum plants. At unmanaged sites λ was <1 due to lower recruitment and lower survival and flowering probability of large plants. Nevertheless, in stochastic simulations, extinction of unmanaged populations of 100 flowering plants was delayed for several decades. Clipping as a management technique rapidly increased population growth because of higher survival and flowering probability of large plants in managed than in unmanaged plots. Transition-matrix simulations from these plots indicated grazing or mowing every second year would be sufficient to ensure a growth rate ≥1 if conditions stayed the same. At frequently grazed sites, the finite growth rate was approximately 1 in most populations of T. montanum . In stochastic simulations, the extinction risk of even relatively small grazed populations was low, but about half the extant populations of T. montanum in central Germany are smaller than would be sufficient for a probability of survival of >95% over 100 years. We conclude that habitat change after cessation of management strongly reduces recruitment and survival of established individuals of this perennial plant. Nevertheless, our results suggest extinction processes may take a long time in perennial plants, resulting in an extinction debt. Even if management is frequent, many remnant populations of T. montanum may be at risk because of their small size, but even a slight increase in size could considerably reduce their extinction risk.     

Combined bioremediation for lead in mine tailings by Solanum nigrum L. and indigenous fungi

Lead-contaminated mine tailings were bioremediated using microbial/phyto remediation. The optimum lead accumulation and tolerance capacity of the plant–microbe partnership were investigated, and their mechanisms were evaluated further under varied levels of lead contamination through a flowerpot experiment in a greenhouse. Enzymes activities revealed that bioremediation has improved fertility and metabolism of tailing soil. The removal efficiency of lead was in the order of microbial/phytoremediation?>?phytoremediation. Solanum nigrum L. was not shown to be a hyperaccumulator for lead. Mucor circinelloides significantly enhanced the growth response and lead accumulation in plants more than Mortierella and Trichoderma asperellum. Moreover, Mortierella was discovered to have good metal tolerance capacity under high Pb concentrations (1200 and 1600?mg?kg^?1). The results for lead bioavailability showed that phytostabilisation serves as a major repair pathway for S. nigrum L. Effective fractions were immobilised for decreased bioavailability by T. asperellum and M. circinelloides. On the contrary, an increased amount of lead was mobilised for increased bioavailability by Mortierella. This study provides new insights into the feasibility of using S. nigrum L. and the aforementioned indigenous fungus strains for large-scale bioremediation of mine tailings.     

Lessons from the 2006 Louisiana health and population survey

The 2005 hurricane season caused extensive damage and induced a mass migration of approximately 1.1 million people from southern Louisiana in the United States. Current and accurate estimates of population size and demographics and an assessment of the critical needs for public services were required to guide recovery efforts. Since forecasts using pre-hurricane data may produce inaccurate estimates of the post-hurricane population, a household survey in 18 hurricane-affected parishes was conducted to provide timely and credible information on the size of these populations, their demographics and their condition. This paper describes the methods used, the challenges encountered, and the key factors for successful implementation. This post-disaster survey was unique because it identified the needs of the people in the affected parishes and quantified the number of people with these needs. Consequently, this survey established new population and health indicator baselines that otherwise would have not been available to guide the relief and recovery efforts in southern Louisiana.     

炼焦过程中单环芳烃排放及源特征

通过不锈钢采样罐采样和液氮预浓缩/气相色谱/质谱系统分析,研究我国山西某地的土法炼焦和机械炼焦生产过程中单环芳烃(MAHs)的排放情况.炼焦过程MAHs以苯、甲苯、(间+对)-二甲苯为主要成分,苯和总MAHs浓度在土法炼焦烟气中最高达3421.0μg/m3和4865.9μg/m³,在机械炼焦无组织排放气体和烟气中分别为548.7μg/m³、1054.8μg/m³和1376.4μg/m³、1819.4μg/m³.焦炭生产过程中MAHs浓度变化显著:土法炼焦过程MAHs前期释放浓度高于后期;机械炼焦无组织排放MAHs在装煤和出焦时明显升高;而机械炼焦烟气中则是装煤时最高,出焦时最低.苯、甲苯、乙苯和二甲苯(BTEX)散点图和相关性分析显示机械炼焦释放MAHs主要来自煤的高温分解,而土法炼焦中MAHs释放则可能除焦煤不完全燃烧释放外还受别的因素影响.苯/甲苯/乙苯/二甲苯比值(B/T/E/X)特别是苯/乙苯(B/E)值显示炼焦释放的MAHs具有不同于其它来源的特征.     

Workplace racial/ethnic similarity,job satisfaction,and lumbar back health among warehouse workers: Asymmetric reactions across racial/ethnic groups

Racial and ethnic minority employees constitute a significant proportion of the U.S. workforce. The literature on demographic similarity in the workplace suggests that the proportion of co‐workers who share the same racial/ethnic background (racial/ethnic similarity) can influence job attitudes and employee well‐being and that the reactions to racial/ethnic similarity may differ between the racially dominant and subordinate groups. This study applies status construction theory to examine the extent to which racial/ethnic similarity is associated with job satisfaction and lumbar back health among warehouse employees. We surveyed 361 warehouse workers (204 whites, 94 African‐Americans, and 63 Latino workers) in 68 jobs in nine distribution centers in the United States. Multilevel analyses indicate that white and racial/ethnic minority groups react differently to racial/ethnic similarity. For job satisfaction, white employees experience higher job satisfaction when they are highly racially/ethnically similar to their colleagues, whereas Latino employees experience higher job satisfaction when they are racially/ethnically dissimilar to others. As for lumbar back health, among Latino and African‐American employees, higher racial/ethnic similarity is associated with better lumbar back health whereas for white employees, the association is the opposite. Across all groups, moderate levels of racial/ethnic similarity were associated with the best lumbar back health. Copyright © 2013 John Wiley & Sons, Ltd.