替代能源措施对区域土地覆盖和土壤侵蚀的影响

以三峡地区的乐天溪流域为例，利用多时相Landsat TM/ETM影像、文献和野外调查资料研究了替代能源对流域土地利用和土壤侵蚀的影响。通过几年替代能源措施实施，乐天溪流域林草覆盖率由1997年的80.6%增加到2002年的83.2%；不仅林草覆盖率增长，而且质量也有较大提高，覆盖度较高的林地和灌丛面积增幅达18.1%和9.1%，相反疏林面积减少37.9%。强度、中度和轻度侵蚀面积分别减少了4.6 km2、26.4 km2和11.5 km2；流域的土壤侵蚀总量由507 259t减至371 592 t，减少26.8%；流域的平均侵蚀模数由1 241 t/km2减至909 t/km2。     

Ecosystem Management on Public Lands: An Application of Optimal Externality to Timber Production

While there are increasing numbers of non-consumptive forest uses on public lands, some silvicultural management systems provide little flexibility for the realization of non-commodity values. Traditional economic decision-making tools, such as net present value, are often applied in a manner which inadequately accounts for the full value of the resource. As a result, sub-optimal management practices are often implemented. By applying a marginal analysis of the optimal externality of different silvicultural systems, it is possible to identify the optimal timber management strategy in terms of the total costs of the timber harvest under alternative uses. Although difficulties arise in valuing non-consumptive uses, contingent valuation with averting costs estimates can establish a lower bound on society's willingness to pay for foregone timber harvesting. Low impact harvest operations and “new forestry” techniques, such as selection harvest cuts, are helpful in reducing the external costs of timber cutting. Therefore, the implementation of such systems may actually increase the socially optimal area of public lands to be harvested under a multiple-use designation.     

UK allotments and urban food initiatives: (limited?) potential for reducing inequalities

The number of urban food initiatives in many regions of the world, notably Europe and the USA, has burgeoned in recent years, and analyses of the impacts of these activities on people and environments are the focus of an increasing academic literature. The impacts documented include enhanced food security, cohesive neighbourhoods, sustainability, and food justice. Yet, another literature presents opposing analyses and focuses on exclusionary aspects of projects and their enabling of a continued neo-liberal reduction in state welfare provision. As a result, there has been an impasse in debates over the potential of urban food projects to reduce inequalities. This paper proposes that the benchmark of the UK allotment system provides a means to examine these opposing positions. It uses the conceptual frameworks of diverse economies and the capital assets framework to attain clarity in the analysis of the many kinds of food-related activities seen in (peri-)urban areas. Drawing on empirical work in Plymouth, UK, it focuses on the potential of the different food ventures to reduce inequalities, given certain contingent economic and political factors. It also presents evidence that the allotment movement despite its initially radical roots can be seen as largely apolitical in the present day and has no leverage over allocation of land to allotment sites. Even so, evidence is growing that both allotments and the newer forms of urban food activities contribute to meeting national and city-level policy objectives, with the potential to enhance food justice and reduce inequalities.     

Outlining policy responses to stimulate automotive car demand by environmental impact reduction

The aim of this paper is to propose an alternative approach for outlining policy responses to stimulate the automotive industry. The scientific community has developed and employed the Delphi method to collect and convey perspectives and impressions, and also define a number of financially viable proposals. The panel of experts takes the view that traditional industrial policy measures denote limited effects to stimulate car demand, in a context of a macro-economic downturn. By contrast, the panel also believe incentives for car demand are important for environmental purposes, for safety and for the diversification of energy sources. The policy measures proposed are fundamental from the viewpoint of overturning path dependencies in the automotive industry which impede the diffusion of alternative vehicles, with respect to business models and consumer attitudes.     

Attitudes towards current and alternative management of the Sundarbans Mangrove Forest,Bangladesh to achieve sustainability

This paper examines the challenges of achieving sustainable management of the world's largest mangrove forest, the Sundarbans (SMF) in Bangladesh. During the past two decades, conflicts between mangrove maintenance and the pressure to provide economic livelihoods to forest-dependent communities (FDCs) have emerged and persisted. The SMF is currently managed by the Bangladesh Forest Department (BFD) under a state property rights regime. This study explores an alternative property rights regime which includes participatory approaches and co-management with FDCs to achieve sustainability, both economically and environmentally. Focus group discussions and a survey were the methods used to assess the prospects. The study finds that the absence of a management partnership between the BFD and FDCs is mainly responsible for the policy failures to achieve sustainable management of the SMF. However, evidence is presented that a ‘co-management’ property rights regime cannot be established until FDC capacity is enhanced through the formation of community level institutions.     

Materials for alternative plant protection

Abstract

Information will be presented as to the use of various materials for alternative protection of crop plants against fungal pathogens.     

Social and Ecological Change over a Decade in a Village Hunting System,Central Gabon

Despite widespread recognition of the major threat to tropical forest biological diversity and local food security posed by unsustainable bushmeat hunting, virtually no long‐term studies tracking the socioecological dynamics of hunting systems have been conducted. We interviewed local hunters and collected detailed hunting data to investigate changes in offtake and hunter characteristics over 10 years (2001–2010) in Dibouka and Kouagna villages, central Gabon, in the context of hunter recollections of longer term trends since the 1950s. To control for changes in hunter behavior, such as trap location and characteristics, we report hunting offtake data per trap. Our results suggest the hunting area was already highly depleted by 2001; local hunters reported that 16 large‐bodied prey species had become rare or locally extirpated over the last 60 years. Overall, we observed no significant declines in hunting offtake or changes in species composition from 2001 to 2010, and offtakes per trap increased slightly between 2004 and 2010. However, trapping distance from the villages increased, and there was a switch in hunting techniques; a larger proportion of the catch was hunted with guns in 2010. The number of hunters declined by 20% from 2004 to 2010, and male livelihood activities shifted away from hunting. Hunters with the lowest hunting incomes in 2004 were more likely than successful hunters to have moved away from the village by 2010 (often in response to alternative employment opportunities). Therefore, changes in trap success (potentially related to biological factors) were interacting with system‐level changes in hunter number and composition (related to external socioeconomic factors) to produce a relatively static overall offtake. Our results highlight the importance of understanding the small‐scale context of hunting to correctly interpret changes or apparent stasis in hunting effort and offtake over time. Cambio Social y Ecológico a lo Largo de Una Década en un Sistema de Cacería Aldeana, Gabón Central     

Slip initiation in alternative and slip-resistant footwear

Slips occur as a result of failure of normal locomotion. The purpose of this study is to analyze the impact of alternative footwear (Crocs?, flip-flops) and an industry standard low-top slip-resistant shoe (SRS) under multiple gait trials (normal dry, unexpected slip, alert slip and expected slip) on lower extremity joint kinematics, kinetics and muscle activity. Eighteen healthy male participants (age: 22.28?±?2.2 years; height: 177.66?±?6.9?cm; mass: 79.27?±?7.6?kg) completed the study. Kinematic, kinetic and muscle activity variables were analyzed using a 3(footwear)?×?4(gait trials) repeated-measures analysis of variance at p?=?0.05. Greater plantar flexion angles, lower ground reaction forces and greater muscle activity were seen on slip trials with the alternative footwear. During slip events, SRS closely resembled normal dry biomechanics, suggesting it to be a safer footwear choice compared with alternative footwear.     

江汉油田老二站提高水质达标率研究

江汉油田老二站采出水经典处理后回注,出水悬浮物、Fe2+和细菌均超标严重,水质达标率低.通过工艺调整,工艺前段利用SRB的除铁作用大幅度降低Fe2+含量;絮凝沉降阶段依据Fenton反应原理,借助H2O2的氧化除铁与杀菌作用,提高絮凝沉降效率,降低悬浮物含量;工艺末段选用多种杀菌剂交替杀菌.结果表明,工艺调整后以100 mg/L的H2O2代替原絮凝剂,间歇添加100 mg/L的杀菌剂Ⅱ,出水含铁1.5 mg/L、悬浮物3.0 mg/L、SRB 10个/mL,老二站水质达到注水水质标准要求,水质达标率达80％.     

直喷式柴油机燃用脂肪酸甲酯的排放特性

脂肪酸甲酯是由生物脂肪经过酯化反应得到的脂肪酸单酯,具有良好的燃料品质和环境友好性,是生物柴油众多种类中的一种.以纯矿物柴油、脂肪酸甲酯、含30%脂肪酸甲酯与70%柴油的混合燃料和含50%脂肪酸甲酯与50%柴油的混合燃料为燃料,在四缸涡轮增压直喷式柴油机上进行的性能对比实验,表明柴油机燃用脂肪酸甲酯能够保持其动力性和燃料经济性,可以显著降低HC和碳烟排放,但会增加CO和NOx排放.脂肪酸甲酯可以作为柴油机的代用燃料进行推广.