保留带与造林带水土和养分再分配效应

保留带（ 保留现有灌丛的带状区域）与造林带（ 砍掉现有灌丛用于栽植林木的带状区域） 沿等高线交替配置的生态技术在四川西部逐渐被推广应用,本文定量分析了该技术中保留带与造林带的水土和养分再分配效应．结果表明：①坡度和雨量级是影响保留带与造林带水土流失的重要因子,其越大则水土流失量越大．②保留带净存储水６１ ４６４ ～１２５ １７９ｔｋｍ －２ａ－１ ,拦截土壤２ １３６ ～２ ８１７ｔｋｍ －２ａ－１ ．③保留带表土层的养分比造林带的提高了１４．６８％ ～７４．８９％ ,造林带表土层的养分比对照提高了３ ．３１％ ～１１４．１６％ ．④保留带和造林带内从上至下的表土层养分有逐渐富积的趋势,且保留带与造林带相邻处的养分变化速率最大．⑤保留带通过地表径流的养分流动净积累了５７５ ．５９ ～１ ６９０ ．６６ ｋｇ ｋｍ －２ａ－１有效Ｎ;而对Ｐ、Ｋ 而言,保留带是否能通过地表径流来净积累养分则主要取决于坡度,坡度越大,越有利于保留带通过地表径流来净积累有效Ｐ、Ｋ．     

Socioeconomic Factors that Affect Artisanal Fishers' Readiness to Exit a Declining Fishery

Abstract:  The emerging world crisis created by declining fish stocks poses a challenge to resource users and managers. The problem is particularly acute in poor nations, such as those in East Africa, where fishing is an important subsistence activity but high fishing intensity and use of destructive gear have resulted in declining catches. In this context developing effective management strategies requires an understanding of how fishers may respond to declines in catch. We examined the readiness of 141 Kenyan fishers to stop fishing under hypothetical scenarios of declines in catch and how socioeconomic conditions influenced their decisions. As expected, the proportion of fishers that would exit the fishery increased with magnitude of decline in catch. Fishers were more likely to say they would stop fishing if they were from households that had a higher material style of life and a greater number of occupations. Variables such as capital investment in the fishery and the proportion of catch sold had weak, nonsignificant relationships. Our finding that fishers from poorer households would be less likely to exit a severely declining fishery is consistent with the literature on poverty traps, which suggests the poor are unable to mobilize the necessary resources to overcome either shocks or chronic low-income situations and consequently may remain in poverty. This finding supports the proposition that wealth generation and employment opportunities directed at the poorest fishers may help reduce fishing effort on overexploited fisheries, but successful interventions such as these will require an understanding of the socioeconomic context in which fishers operate.     

“蛇形”带式输送机转向稳定性研究

“蛇形”带式输送机在转弯过程中,失稳情况十分常见,对其转弯稳定性的研究可以避免生产事故,提高生产效率。根据实际工况中“蛇形”带式输送机的受力情况,得到转弯过程中各小车的运动方程,结合转向油缸对于小车转弯的影响,得到油缸和小车转弯角度之间的关系,建立起转弯过程动力学模型。运用实验设备进行实车实验,利用MATLAB/Simulink软件对“蛇形”带式输送机系统转弯过程进行了仿真分析,研究了“蛇行”带式输送系统在不同转向条件下的工作状态。将实验结果和仿真结果进行对比分析,得出“蛇形”带式输送机转弯的临界条件,为“蛇形”带式输送机稳定域估计提供依据。     

Ecology,ecological poverty and sustainable development in Central Himalayan region of India

The people inhabiting the mountains of the Central Himalayan region of India are heavily dependent on their immediate natural resources for their survival. However, this resource-poor mountain ecosystem is gradually becoming unable to provide a minimum standard of living to its continually growing population. In this ecosystem, human population is doubling every 27–30 years, against the declining resource base, particularly forests. Forest are disappearing both quantitatively and qualitatively. Against the requirement of 18 ha of forest land to maintain production in 1 ha of cultivated land, the ratio of forests to cultivated land is only 1.33: 1. The present production from grasslands supports 8 units of livestock, against the ideal 2 units, and the gap between the demand and deficit of fodder is more than 5-fold. Loss of vegetative cover is resulting in drying up of water resources, compelling the women to walk longer distances to collect water. This ecological deterioration, apart from human growth and interference, is compounded by mountain specificities such as inaccessibility, fragility, marginality, diversity, niche and adaptability. The specificities manifest in isolation, distance, poor communication, limited mobility, etc., resulting in limited external linkages and replication of external experiences, and slow pace of development. They, therefore, restrict options for economic growth, effecting poverty and affecting the quality of life of the people of the region. Poverty, in this mountain ecosystem cannot be understood and assessed independent of ecological wealth and would better be termed as ecological poverty. The development efforts to be effective in alleviating poverty here, should take into account mountain specificities and incorporate options which have larger human dimensions, such as mechanisms for population control, socio-economic and cultural conditioning, indigenous knowledge systems of the local people and simple technologies that are already in practice or have potential and are based on least external inputs.     

Integrating livelihoods and conservation in protected areas: understanding the role and stakeholder views on prospects for non-timber forest products,a Bangladesh case study

Protected areas (PAs) represent a key global strategy in biodiversity conservation. In tropical developing countries, the management of PAs is a great challenge as many contain resources on which local communities rely. Collection and trading of non-timber forest products (NTFPs) is a well-established forest-based livelihood strategy, which has been promoted as a potential means for enhanced conservation and improved rural livelihoods in recent years, even though the sustainability or ecological implications have rarely been tested. We conducted an exploratory survey to understand the role and stakeholder views on conservation prospects and perceived ecological feasibility of NTFPs and harvesting schemes in a northeastern PA of Bangladesh, namely the Satchari National Park. Households (n?=?101) were interviewed from three different forest dependency categories, adopting a stratified random sampling approach and using a semi-structured questionnaire. The study identified 13 locally important NTFPs, with five being critically important to supporting local livelihoods. Our study suggests that collection, processing and trading in NTFPs constitutes the primary occupation for about 18% of local inhabitants and account for an estimated 19% of their cash annual income. The household consensus on issues relating to NTFPs and their prospective role in conservation was surprisingly high, with 48% of respondents believing that promotion of NTFPs in the PA could have positive conservation value. The majority (71%) of households also had some understanding of the ecological implications of NTFP harvesting, sustainability (53%) and possible management and monitoring regimes (100%). With little known about their real application in the field, our study suggests further investigations are required to understand the ecological compatibility of traditional NTFP harvesting patterns and management.     

Evaluating poverty–environment dynamics

Developing indicators to more effectively evaluate poverty–environment dynamics and inform policy is an urgent research priority. It is critical that these indicators are used in ways that accurately represent the relationship they are meant to inform. This article evaluates the theory and use of poverty–environment indicators, a relatively new tool developed to aid in the design and evaluation of poverty reduction strategies in the context of environmental change. We argue that while they have great potential, in their current form and use, poverty–environment indicators may contribute to critical misunderstandings of processes on the ground. These issues stem from a problematic and largely unacknowledged process of simplifying particular poverty–environment relationships. This article lays out the problematic character of this simplification process, and suggests how we might address these problems to create more useful understandings of poverty–environment dynamics to inform policy.     

Poverty issues in a national wildlife reserve in China

The increasing interest in environmental conservation is a global phenomenon. In many countries, natural reserves or protected areas (PAs) have been established to restrict human activities and to enhance natural ecosystems, which potentially benefit the planet as a whole. However, this often demands some sacrifices from local residents who may have to give up resources they rely on or suffer losses caused by wildlife. This issue potentially becomes aggravated in densely populated areas where many people and economic activities are impacted. This paper presents research findings on poverty issues in a newly established national natural reserve in China, Hengshui Lake Natural Reserve. The paper addresses the characteristics of poor households in the reserve and the interaction between these families and the reserve. In addition, poverty alleviation measures are analysed and additional measures to reduce poverty and conflicts between the reserve and local residents are recommended.     

Exploring relationships between conservation and poverty reduction in wetland ecosystems: lessons from 10 integrated wetland conservation and poverty reduction initiatives

It is well known that whilst wetlands deliver a wide range of services vital for human well-being, they are being rapidly degraded and lost. Losses tend to be higher where human populations are increasing most and demands for economic development are greatest. Multidisciplinary management approaches that integrate conservation and development objectives in wetlands are therefore urgently requested for by the Ramsar Convention on Wetlands. This paper describes the evaluation of 10 wetland management case studies from Asia, Africa and South America that adopted such an integrated approach. The evaluation assessed the outcomes of these integrated initiatives to identify conditions and processes for linking conservation and poverty reduction objectives in wetlands. The findings are also compared with other assessments of integrated approaches, particularly in terms of their effectiveness in optimizing conservation and poverty reduction outcomes. The results from our studies suggest an ongoing evolution of such integrated interventions, which also implies cycles of learning from past mistakes. Overall, our results highlight the significant variation between wetlands in types and quantities of services they provide and emphasize the need to view many ecological issues as social challenges for equitable solutions to both wetlands and people. The analysis further shows that the positive on-ground results owe much to the interdisciplinary problem analysis, whereby interventions can move from treating symptoms to addressing root causes. while no blueprint emerged on how to successfully integrate conservation and poverty reduction in wetlands, important lessons for future interventions were drawn.     

辽宁沿海地区用水效率与经济的耦合协调发展评价

论文构建辽宁沿海经济带用水效率与经济耦合协调发展评价指标体系,首先运用改进的突变模型对2001—2010 年辽宁沿海经济带用水效率和经济发展各子系统进行状态评估,其次运用耦合协调模型对辽宁沿海经济带各市用水效率与经济发展的耦合协调度进行评价。研究结果表明：①辽宁沿海经济带整体用水效率与经济发展耦合度水平从0.437 提高到0.498,呈缓慢提高状态,但一直处于拮抗阶段。用水效率水平与经济发展水平差距不断减小,耦合协调度从0.254 增大到0.408,呈增大趋势但仍处于中低度协调水平;②辽宁沿海经济带各市用水效率与经济发展都处于上升趋势,其中用水效率最好的为大连市,用水效率评估值已达到0.887,其次为锦州、营口和葫芦岛,丹东和盘锦市用水效率处于最低水平,分别为0.604和0.535。经济发展水平最高的为大连市,其次为营口和盘锦市,丹东、锦州和葫芦岛较差; ③各市耦合度均处于拮抗阶段,并且处于上升趋势。大连市和营口市耦合协调度2010年已分别达到0.457 和0.401,已从低度协调进入中度协调且呈不断上升趋势,丹东、锦州、盘锦和葫芦岛均处于低度协调阶段,呈波动式上升。各市的经济发展滞后于水资源利用效率的提高,导致耦合协调度一直处于中低度协调水平;④辽宁沿海经济带耦合度和协调度的区域差距在不断减小,经济带协同发展趋势越加明显。     

辽河干流消落区沉积物重金属污染特征研究

通过测定辽河干流消落区10个断面中0~5cm、5~15cm、15~30cm深沉积物中重金属Pb、Cu、Zn、Cd含量,揭示消落区干－湿交替下沉积物重金属的污染特征.采用原子吸收分光光度计测定重金属含量,并采用地质累积指数与潜在生态危害指数评估重金属污染状况.结果表明,除Cd外,Cu、Zn与Pb的含量均值分别为31.4mg/kg、28.14mg/kg、43.75mg/kg,均低于中国土壤环境质量标准I级土壤标准;Cd含量均值1.438mg/kg,是中国土壤环境质量标准I级土壤标准的7.19倍,是辽河水系沉积物平均值的1.29倍,辽宁省土壤背景值的13.31倍,表明研究区Cd污染严重.地质累积指数评价表明,Pb、Cu、Zn的污染程度低于1级,Cd达2级中度污染以上,在通江口达3.92,为5级强污染;据潜在生态危害评价,达牛渡口上游干流潜在生态危害指数为强以上,通江口生态危害指数最高,且生态危害主要来源于Cd.相关性分析表明,Pb、Cu与Zn间相关性极显著,可能有相同的污染源,Cd有单独的污染源.