Participatory assessment of soil degradation in the uplands of southwestern Tanzania: Implications for sustainable agriculture and rural livelihoods

Rural household food insecurity and poverty are closely linked to soil degradation in Sub-Saharan Africa. However, causes, degradation processes, coping strategies and need for interventions may vary from one place to another. This study was conducted in Mbinga District, SW Tanzania, to investigate causes and biophysical processes of soil degradation; effects on livelihoods, coping strategies and entry points for interventions. Implications for sustainable production and rural livelihoods are discussed. Participatory Rural Appraisal (PRA), household surveys using a short open-ended questionnaire and biophysical exploration were the research tools used. Soil fertility depletion resulting from continuous cropping and erosion losses is the main form of soil degradation. Maize yield was 57% lower in fertility-depleted farms than in productive farms. Soil pH, Ca²⁺, Mg²⁺ and CEC accounted for 79% of variations in maize yield. Organic soil fertility amelioration was a common strategy used by smallholders. Use of beneficial tree and shrub fallows is the most environmentally, economically and socially promising improvement that can be used to build on the existing strengths of farmers' knowledge and strategies. Subsidy for the right type of fertilizers, infrastructure improvement and education of farmers on proper use of fertilizers should significantly contribute to improved and sustainable production and livelihoods.     

Sustainable poverty alleviation through a forestry project in Tamilnadu State of India

The World Development Report 2000–2001 recommends action on three complementary and synergistic fronts for poverty alleviation – promoting opportunity, facilitating empowerment and enhancing security. This paper analyses the Tamilnadu Forestry Project, funded by US$100 million from the Japan Bank for International Cooperation, for community forestry. The project was launched in 1997–1998 in this southern state of India and has evolved into a comprehensive poverty alleviation programme for the forest abutting villages where the proportion of poor people is largest. It endeavours to explain how the project provides the above three elements at the local level for sustainable poverty alleviation. Regeneration of forests, improvement of basic infrastructure through integration of line departments and promotion of alternate livelihoods provide ample economic opportunities. Establishment of Village Forest Councils, and delegation of sufficient powers to these Councils, has empowered the poorest of the poor. Tree assets, promotion of alternate income generation activities and water harvesting structures have provided security by reducing vulnerability to natural vagaries, particularly drought. In this project, the restoration of biodiversity and people development go hand in hand in a synergistic way that makes the project worth replicating elsewhere in the country and other parts of the world, with suitable modifications.     

Identification of agricultural factors for improving sustainable land resource management in northern Thailand: A case study in Chiang Mai Province

This paper aims to identify the land-use factors benefiting sustainable land management in terms of environmental conservation. For evaluating the impacts of land use on the environment, the following parameters were used: chemical fertiliser and pesticide use, land-use structure and diversity. The farmers' income, land tenure and farming scale were selected for their influence on agricultural sustainability. The analysis shows a rapid increase in use of chemical fertiliser and pesticide in the past 40 years, and an observable increase in land-use diversity. The amount of chemical fertiliser used per unit area in large-scale farming was lower than that at small scales, but large-scale farming consumes more pesticide than small-scale farming. A significant negative correlation was observed between the proportions of the holdings possessing land and the holdings using the chemical fertiliser. In order to achieve sustainable agriculture, it is necessary to manage crop systems and land use towards selecting new strains and varieties of crops and fruits with a lower demand for chemical fertiliser and a higher resistance to disease and pests, balancing large- and small-scale farming, and ensuring land tenure and economic incentives.     

An overview of the impacts of changes in common property resources management in the context of globalisation: A case study of India

Socio-economic development of mankind and well-being depend on the environment and the way in which development influences the environment. Thus, environment and development are interdependent. In fact, economic development is closely linked with the development of resources. These resources can be classified into three categories: public goods, semi-public goods (also known as common property resources) and private goods. In poor countries common property resources make a valuable contribution to the sustainable livelihoods of rural populations. The impact of globalisation on the commons shows various patterns of ownership, control, use and misuse. The commons were subjected to degradation as well as conservation in the process of centralized management in India. After the reform period, the administration of natural resources was given significant attention by specialized departments such as the Forest Department and the Revenue Department. All the land, apart from private land, was regarded as state property and controlled by the state. This paper highlights the need to examine the common property resources sector in the context of wider economic policy reform processes in the Indian economy.     

Ecological restoration,social-economic changes and sustainable development in the Three Gorges Reservoir area: A case study in Yunyang,Chongqing Municipality

The Three Gorges Reservoir area contains high mountains and deep valleys. The fragile mountainous ecosystems are facing problems such as overpopulation, less available farmland, ecological degradation and poverty. The construction of the Three Gorges Project and a series of ecological restoration activities and social-economic changes have influenced the present and future viability of this area. The measures which have been taken indicate that restoring and renewing the degraded ecosystems and improving the economy is a prerequisite and is possible. Yunyang, a typical county, both in terms of poverty and ecological degradation in the Three Gorges Reservoir area of Chongqing Municipality, was chosen for the case study. This paper discusses the impacts of the Grain-for-Green project, ecological agriculture, urban and infrastructure building and ecological immigrants on the regional sustainable development through detailed field investigation and a questionnaire survey.     

GIS与层次分析法相结合的生态环境综合评价研究——以渝西地区为例

将GIS与层次分析法相结合应用于渝西地区生态环境质量综合评价。首先,根据渝西地区生态环境的基本特点确定生态环境质量综合评价的指标体系和基本评价单元,通过层次分析法,确定各评价指标的权重,计算出每个评价单元的生态环境质量综合指数和分指数;然后运用GIS技术,根据每个评价单元的质量指数和分指数,自动生成渝西地区生态环境综合评价等级图;在此基础上,对渝西地区生态环境整体及各不同侧面质量状况的空间分异规律进行分析和研究。结果显示,渝西区生态环境质量基本上由南向北逐渐降低,与自然环境状况的空间格局大体吻合,但局部地区有差异。表明自然条件对渝西地区生态环境质量的空间分异起决定性作用,但社会经济和环境污染等因素同样对生态环境具有重要影响,在某些情况下,甚至可以成为决定因素,并在一定程度上改变生态环境的空间格局。     

Calculation of the minimum ecological water requirement of an urban river system and its deployment: A case study in Beijing central region

The minimum ecological water requirements of an urban river system and water deployment are key elements in integrated water resources planning and urban ecological construction. Based on a review of ecological water requirement calculation methods and considering the different ecological functions of an urban river system, the ecological function method was used in this paper to calculate the components of the ecological water requirements of an urban river. An envelope curve-based method was proposed for assessing the minimum ecological water requirements of an urban river system. Water resources deployment strategies designed to meet the minimum ecological water requirements were described. Then, the minimum ecological water requirements of the urban river system in Beijing central region, selected as a case study, were investigated. The key parameters for assessing the minimum ecological water requirement in the Beijing urban river system were determined. Based on the ecological objectives and the current status of the different urban river systems within the Beijing central region, the minimum ecological water requirements were calculated. Different types of water sources, including rainwater, upstream water, and reclaimed water, were deployed to meet the ecological water requirements for the urban river system in the Beijing central region.     

平原河网地区滨岸带外来植物入侵现状及影响研究——以上海青浦区为例

河流滨岸带作为一种典型的开放系统,在受到外界干扰的条件下极易被外来植物所入侵并受到严重影响。以上海青浦区为例,通过对河流滨岸带生态系统入侵植物分布及现状调查,以及对两种入侵植物：白花三叶草（Trifolium repens）和加拿大一枝黄花（Solidago canadensis）群落的物种多样性及其土壤特性的实证研究,探讨外来植物入侵对河流滨岸带生态系统造成的影响。结果表明：目前该地区河流滨岸带外来入侵植物共有14科24种,其科、种数分别占到该生态系统所有植物的48．3％与26．1％。入侵植物白花三叶草与加拿大一枝黄花在春、秋两季均显著降低了河流滨岸带植物群落的物种多样性。此外,两种人侵植物也对当地河流滨岸及土壤特性造成了不同程度的影响,其中对土壤含水量、pH值的影响最为显著。该研究填补了平原河网地区河流滨岸带生态系统外来植物入侵研究的空白,有助于今后开展对该生态系统的评价、恢复及管理工作。     

江南丘陵红壤区的农业水资源特征与调控利用——以江西省余江县为例

农业水资源按分布空间分为大气降水、地表水、土壤水和地下水。江南丘陵红壤区的各类水资源特征是:大气降水丰沛而时空分配不均;地表水多而径流、蒸发量大;红壤贮水库容小、深层水多而有效性差;地下潜水较多而承压水少。针对上述特征,应因地制宜通过工程、生物、农艺措施进行水资源调控,针对“四水”进行人工降雨,地表水集蓄,增加土壤深层水、有效水利用和潜水开发等,以蓄丰补欠、趋利避害,提高水资源的利用率。     

A simulation framework for water allocation to meet the environmental requirements of urban rivers: model development and a case study for the Liming River in Daqing City,China

In this paper, we describe the development of a simulation framework for allocating water from different sources to meet the environmental flows of an urban river. The model permits the development of a rational balance in the utilization of storm water, reclaimed water from wastewater treatment plants, and freshwater from reservoirs with consideration of the limited capacities of different water resources. It is designed to permit the full utilization of unconventional water sources for the restoration of river water quality by increasing river flow and improving water quality. To demonstrate practical use of the model, a case study is presented in which the model was used to simulate the environmental water allocation for the Liming River in Daqing City, China, based on the three water sources mentioned above. The results demonstrate that the model provides an effective approach for helping managers allocate water to satisfy the river’s environmental water requirements.     

泥炭沼泽土壤酶活性对水热条件变化的响应及其与CO_2释放通量的关系——以小兴安岭地区为例

采用实验室培养的方法,研究了小兴安岭地区两类典型的泥炭沼泽:苔草型泥炭沼泽和泥炭藓型泥炭沼泽中几种水解酶活性(β-葡萄糖苷酶、酚氧化酶)对不同温度和水位变化的响应,以及与CO_2释放通量的相瓦关系.结果表明:β-葡萄糖苷酶活性在两类泥炭沼泽中受多种因素制约,在一定湿度范围内受水位控制较明显,当土壤湿度降低到一定程度时,温度对土壤酶活性影响增强.酚氧化酶活性与温度密切相关,但对温度变化的响应存在明显的季节性差异.相对而言,苔草型泥炭沼泽中β-葡萄糖苷酶和酚氧化酶活性显著高于相同培养条件下泥炭藓型泥炭沼泽.总体上,苔草型泥炭沼泽中水解酶活性较泥炭藓型泥炭沼泽中高,但是其CO_2释放通量却低于泥炭鲜型泥炭沼泽,表明与有机碳分解有关的水解酶的活性高低不能作为解释泥炭沼泽CO_2释放通量大小的唯一指标.