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1.
Integrated rice-fish culture: Coupled production saves resources   总被引:9,自引:0,他引:9  
Rice is a key component in global food security, as it is the main ingredient in the daily diets of around 3 billion people, especially in Asia. Like all agricultural production, rice cultivation depends on scarce natural resources. This article briefly outlines the utilization of land and water in rice production, and suggests an approach for optimizing use efficiency, namely through the combination of rice and fish culture. The authors argue that the utilization of land and fresh water is optimized through integrated and complementary production of rice and fish — two basic foods items in daily local diets. The article reviews currently available scientific literature on integrated rice‐fish systems. Rice‐fish culture systems are briefly characterized, and respective yield potential and interactions between rice and fish are discussed. Results of socio‐economic surveys regarding the adoption of integrated rice‐fish culture are summarized. The article also reviews literature on the impact of fish culture on rice field ecology as outlined in studies on weed infestation, insect populations, and greenhouse gas emissions. The article concludes that rice‐fish culture can be an option to help rice producing countries keep pace with soaring domestic demand for food, especially fish. Integrated rice and fish culture optimizes the benefits of scarce land and water resources through complementary use, and exploits the synergies between fish and plant.  相似文献   

2.
Land degradation continues to be a major threat to local and national food security. With limited potential to develop new land, any increase in agricultural production must be sought largely through the better use of land already under cultivation. Concerns for the global environment associated with agriculture worldwide have also increased in recent years and require more coordinated efforts at global and national levels with decentralisation of activities at the local level.
This article presents an overview of land resources potential for food production, the processes and extent of land degradation and its economic and environmental costs and impacts, and highlights some macro-economic policies and institutional measures for the prevention of land degradation and rehabilitation of degraded lands. A people-centred programme is presented as a basis for decentralising activities for sustainable land use and land management. Finally, the need for better coordinated efforts of concerned UN, multinational agencies and NGOs for the implementation of Agenda 21 and related conventions is stressed.  相似文献   

3.
Wetlands are critical natural resources in developing countries where they perform a range of environmental functions and provide numerous socio-economic benefits to local communities and a wider population. In recent years, however, many wetlands throughout eastern Africa have come under extreme pressure as government policies, socio-economic change and population pressure have stimulated a need for more agriculturally productive land. Although wetland drainage and cultivation can make a key contribution to food and livelihood security in the short term, in the long term there are concerns over the sustainability of this utilization and the maintenance of wetland benefits. This article draws upon recent research carried out in western Ethiopia, which addressed the sustainability of wetland agriculture in an area of increasing food insecurity and population pressure. It discusses the impacts of drainage and cultivation on wetland hydrology and draws attention to local wetland management strategies, particularly those characterized by multiple use of wetlands, where agriculture exists alongside other wetland uses. The article suggests that where multiple wetland uses exist, a range of benefits can be sustained with little evidence of environmental degradation. Ways of promoting and empowering such sustainable wetland management systems are discussed in the context of the wider need for water security throughout the region.  相似文献   

4.
Many developing countries in the tropics have focused on tourism to generate additional income sources and to diversity the economy. Coastlines in particular have been on the forefront of tourist infrastructure development. Here, the presence of a large number of tourists has often had negative consequences for the sustainable use of the available resources, which in turn has had an effect on the integrity of the ecosystems. In this paper, the situation is described for the use of freshwater resources on the east coast of Zanzibar, Tanzania. This region is water poor, relying on freshwater derived from seasonal rains and stored in less efficient aquifers, which consist of freshwater lenses floating on the underlying seawater. Tourism in the area has grown rapidly in recent years and is expected to further increase in the future. This development is expected to put additional pressure on the freshwater resources of the east coast, which show already signs of over-use. The consequences of overexploitation can include the lowering of the groundwater table, land subsidence, deteriorating groundwater quality, and saltwater intrusion. These, in turn, determine the living conditions in coastal areas and the effects will be felt both by the local populations and the tourist industry. An investigation is made into the causes and consequences of water abstraction by the tourist industry. The results show that present levels of withdrawal are not sustainable, and parts of the local populations are already experiencing water deficits on a daily basis. In the future, if the expected increase in tourist numbers occurs, the pressure on the aquifers will correspondingly increase. The results could be that the tourism in the area becomes unsustainable, which could have an adverse effect on the national economy and also on the local population and environment. Therefore, a precautionary water-management approach is suggested.  相似文献   

5.
Unauthorized mines are not uncommon in mineral-rich regions of poorer countries, and India is no exception. Whether they constitute merely a law and order problem including safety issues, or there are important social and economic questions involved has yet to be thrashed out. The mining industry, at regional, national and international levels, is ambivalent towards such mining, tending to draw attention away from their informal nature to the size factor.
This article looks into the problem of such informal mining in the light of empirical surveys in eastern Indian collieries. These are called peoples' mines and they serve a significant purpose in local economies. The article's thesis is that peasant communities are trying to claim back a portion of the local resources lost to them through appropriation by mining companies thus re-asserting their traditional rights to local mineral resources. In conclusion, the need for a new moral economy for mining regions is stressed: an economy in which local communities will play a powerful role.  相似文献   

6.
This article examines key socio-ecological interactions identified during a climate change vulnerability assessment in the Alinytjara Wilurara natural resources management (NRM) region of South Australia. The complex local socio-ecological interactions are highlighted to guide a response to the challenge of adapting to climate change within the region. Recognising several key desert drivers which perpetuate degraded socio-ecological systems, this article recommends that a range of strategies be employed simultaneously to enhance local environmental management in association with remote indigenous communities, including: linking people and NRM more closely; tracking funding but ensuring systems can withstand periods of limited financial support; developing cross-sectoral and cross-institutional links; empowering and engaging communities; communicating effectively; and actively supporting local and traditional environmental knowledge. Unless climate change adaptation responses within the region are conceptualised and enacted within the context of complex local socio-ecological systems, NRM will not improve and social vulnerability will increase.  相似文献   

7.
A GIS-based land evaluation model was developed to determine the food, feed, and fuelwood sufficiency of all districts in Nepal. Resource surpluses or deficits were calculated for each district for 1981, the year for which the national land resource data were available. Of the three resources, feed supplies were found to be the most critical. Feed deficits occurred in 57% of all districts in 1981, while food and fuelwood deficits occurred in less than 10% of all districts. Different scenarios were carried out for the year 2000 to estimate the magnitude of future resource deficits, assuming resource use and yields in Nepal remain constant in the face of growing population and livestock numbers. Linking resource data with spreadsheet and GIS systems provides a new way to understand and evaluate resources at the district and national levels. To more fully capture the usefulness of this approach, information on rates of change in productivity and land use is needed.  相似文献   

8.
Land Degradation: A Challenge to Ethiopia   总被引:11,自引:3,他引:8  
Land degradation is a great threat for the future and it requires great effort and resources to ameliorate. The major causes of land degradation in Ethiopia are the rapid population increase, severe soil loss, deforestation, low vegetative cover and unbalanced crop and livestock production. Inappropriate land-use systems and land-tenure policies enhance desertification and loss of agrobiodiversity. Utilization of dung and crop residues for fuel and other uses disturbs the sustainability of land resources. The supply of inputs such as fertilizer, farm machinery and credits are very low. The balance between crop, livestock, and forest production is disturbed, and the farmer is forced to put more land into crop production. For environmentally and socially sustainable development, there is an urgent need to promote awareness and understanding of the interdependence of natural, socioeconomic, and political systems at local and national levels. Understanding the current status and causes of land degradation is very important. This paper reveals the important elements of land degradation in Ethiopia and suggests possible solutions that may help to ameliorate the situation.  相似文献   

9.
While local food production may be beneficial in terms of developing the local economy and reducing greenhouse gases from transportation, sustainability strategies focused on local food production may generate their own risks due to yield variability. We have developed a robust optimization (RO) model to determine the minimum amount of land (cropland and pasture) required to grow food items that would satisfy a local population’s (accounting for gender and age) calorie and nutrient needs. This model has been applied to Boone County, Missouri, which has a population of approximately 170,000. Boone County is 1790 km2, with 16% of the land defined as cropland and 30% defined as pasture. The model includes 27 nutrients from 17 potential foods that could be produced: six fruits and vegetables, five grains and six animal-sourced foods. Yield estimates are based on the predominate methods of agriculture in the USA. We first run our model assuming no variability, using the midpoint yield estimates. Then, to quantify uncertainty in yield for different food types, we use historical yield data over 10 years to estimate this variability and run our RO model under these variability estimates. We compare the two model results to illustrate the impact of data uncertainty on meeting sustainable local food for communities. Solutions suggest that nutrition needs can be met for the Boone County population within the land area defined.  相似文献   

10.
When local resource users detect, understand, and respond to environmental change they can more effectively manage environmental resources. This article assesses these abilities among artisanal fishers in Roviana Lagoon, Solomon Islands. In a comparison of two villages, it documents local resource users’ abilities to monitor long-term ecological change occurring to seagrass meadows near their communities, their understandings of the drivers of change, and their conceptualizations of seagrass ecology. Local observations of ecological change are compared with historical aerial photography and IKONOS satellite images that show 56 years of actual changes in seagrass meadows from 1947 to 2003. Results suggest that villagers detect long-term changes in the spatial cover of rapidly expanding seagrass meadows. However, for seagrass meadows that showed no long-term expansion or contraction in spatial cover over one-third of respondents incorrectly assumed changes had occurred. Examples from a community-based management initiative designed around indigenous ecological knowledge and customary sea tenure governance show how local observations of ecological change shape marine resource use and practices which, in turn, can increase the management adaptability of indigenous or hybrid governance systems.  相似文献   

11.
Water resources and land use are closely linked with each other and with regional climate, assembling a very complex system. The understanding of the interconnecting relations involved in this system is an essential step for elaborating public policies that can effectively lead to the sustainable use of water resources. In this study, an integrated modelling framework was assembled in order to investigate potential impacts of agricultural expansion and climate changes on Irrigation Water Requirements (IWR) in the Taita Hills, Kenya. The framework comprised a land use change simulation model, a reference evapotranspiration model and synthetic precipitation datasets generated through a Monte Carlo simulation. In order to generate plausible climate change scenarios, outputs from General Climate Models were used as reference to perturbing the Monte Carlo simulations. The results indicate that throughout the next 20 years the low availability of arable lands in the hills will drive agricultural expansion to areas with higher IWR in the foothills. If current trends persist, agricultural areas will occupy roughly 60% of the study area by 2030. This expansion will increase by approximately 40% the annual water volume necessary for irrigation. Climate change may slightly decrease crops' IWR in April and November by 2030, while in May a small increase will likely be observed. The integrated assessment of these environmental changes allowed a clear identification of priority regions for land use allocation policies and water resources management.  相似文献   

12.
This research examines price in local food systems to identify whether the perception that local is more expensive is justified. This study seeks to contribute to the field by addressing the dearth of quantitative price and availability research and building upon existing empirical research by considering a broader range of distribution channels and organic produce. Without a stronger understanding of pricing structures and distribution models, local food initiatives are based on assumptions rather than evidence. Using a case-study approach of the Region of Waterloo (Ontario, Canada), price and product data were collected at 11 outlets over a 6-month period. The study involved regression analysis of six locally produced fruits and vegetables based on local, Ontario, and organic attributes associated with the products and comparison with consumer willingness-to-pay research. Results show that local produce in the case study is not consistently more expensive than the non-local option. Both price discounts and premiums are found, depending on the product. These findings challenge the “local is more expensive” assumption and support suggestions that local food systems can be spaces for social inclusion. The organic attribute is associated with a price premium in all cases and may create confusion among consumers given frequent overlap between the local and organic attributes. Proponents of local food can use the results of this study to inform programme and policy development. Most notably, the study suggests that education around the distinction between local and organic as well as challenges to the price perception could be of benefit.  相似文献   

13.
Two of the eight Millennium Development Goals (MDGs) adopted by the United Nations General Assembly in September 2000 are: eradication of extreme poverty and hunger; and ensuring environmental sustainability. The link between depressed livelihoods and unsustainable use of land and natural resources can be seen in Kenyan rangelands. Here, the local community is dependent on land and its resources for livelihoods, but the demand and competition is increasing, endangering both the resources they depend on and threatening environmental health. Amboseli is an Arid and Semi-Arid Land (ASAL) area that experiences ecological constraints, resource limitations, and low economic investment. Local communities in such landscapes are resource-dependent for their daily livelihoods, and have few socio-economic opportunities. Pastoralism, which is the main source of their wealth, continues to decline and exploitation by a few local elites and poor local leadership further depresses livelihoods. Other challenges to these poor rural landscapes are increasing human population which increases demands on natural resources and environment; persistent hunger; low universal primary education; poor gender equality and empowerment of women; environmental degradation; and lack of local and global partnership for development. This paper focuses on the two Millennium Development Goals mentioned above. Linkages, challenges and opportunities in enhancing rural livelihoods while promoting environmental sustainability in rural landscapes of the Amboseli Rural Landscape are discussed.  相似文献   

14.
Current planning policy places increased emphasis on the protection of the natural environment. The negotiation of planning agreements between local authorities and developers has emerged as one route through which the private sector has sought to compensate for the loss of environmental resources arising from development. We argue that the utilization of conservation gain mirrors the valuation procedures for public goods found within cost — benefit techniques, which may be inappropriate for the treatment of natural environmental systems. The paper examines the negotiation of these gains from the perspective of different actors in the land development process. Both quantitative and interview material from four local planning authorities are used. The paper concludes by considering the scope for a broader use of conservation gain.  相似文献   

15.
Agroforestry as alternative land-use production systems for the tropics   总被引:1,自引:0,他引:1  
The science of agroforestry has progressed significantly during the past three decades. This article describes and documents various prominent traditional agroforestry systems. In-depth research on interactive processes of some agrisilvicultural systems have been undertaken and quantified. It has been found that the presence of woody species can enhance nutrient cycling, and can improve soil productivity, soil conservation and soil biotic andfaunal activities. In simultaneous systems however, their presence can also cause competition with the associated food crops. Most agroforestry systems constitute ecologically and bio-physically sustainable land use systems. Some are highly sustainable and economically viable, in particular the highly complex and specialized types, such as the damar and rubber agroforests in Indonesia. Agroforestry systems have potential uses in stabilization of sloping lands and buffer zones around forest reserves, for recovering degraded lands, and for improving the productivity of the bush fallow system. Despite rapid progress in biophysical research, field application of the science of agroforestry is still minimal. This article examines the possibilities of exploring the multiple contributions of trees to food security, rural income generation, diversity of products and ecosystem conservation within sustainable agroforestry contexts. Research efforts in the new millennium need to focus more on practical research and also on socio-economic and policy factors that can enhance beneficial application of the science in the near future to smallholder farmers in the tropics.  相似文献   

16.
The East Usambara Mountains, recognized as one of the 25 most important biodiversity hot spots in the world, have a high degree of species diversity and endemism that is threatened by increasing human pressure on resources. Traditional slash and burn cultivation in the area is no longer sustainable. However, it is possible to maintain land productivity, decrease land degradation, and improve rural people’s livelihood by ameliorating cultivation methods. Improved agroforestry seems to be a very convincing and suitable method for buffer zones of conservation areas. Farmers could receive a reasonable net income from their farm with little investment in terms of time, capital, and labor. By increasing the diversity and production of already existing cultivations, the pressure on natural forests can be diminished. The present study shows a significant gap between traditional cultivation methods and improved agroforestry systems in socio-economic terms. Improved agroforestry systems provide approximately double income per capita in comparison to traditional methods. More intensified cash crop cultivation in the highlands of the East Usambara also results in double income compared to that in the lowlands. However, people are sensitive to risks of changing farming practices. Encouraging farmers to apply better land management and practice sustainable cultivation of cash crops in combination with multipurpose trees would be relevant in improving their economic situation in the relatively short term. The markets of most cash crops are already available. Improved agroforestry methods could ameliorate the living conditions of the local population and protect the natural reserves from human disturbance.  相似文献   

17.
Scholars have noted that race and ethnicity, socio-economic status (SES) as well as other socio-demographic factors may limit participation in local food systems based on the historic and structured patterns of inequalities that remain in communities promoting alternative agriculture and food (agrifood) activities. However, few empirical studies have examined the barriers which prevent people from participating in local food system activities. This paper uses survey data from the 2008 Ohio Survey of Food, Agriculture and Environmental Issues to consider whether barriers such as interest, time, financial resources, geography and space impact the participation of households in home gardening. Results from logistic regression show that SES, the availability of space and housing type are important factors which limit or enable household participation in home gardening. This paper contributes to our understanding of the barriers that prevent households from participating in home gardening, a form of food system localisation that, while a potentially powerful way to transform the agrifood system, has been underexamined in its own right.  相似文献   

18.
This paper presents an assessment of the potential impact of the EUs biofuel directive on European land use and biodiversity. In a spatially explicit analysis, it is determined which ecologically valuable land use types are likely to be directly replaced by biofuel crops. In addition, it is determined which land use types may be indirectly replaced by biofuel crops through competition over land between biofuel and food crops. Four scenarios of land use change are analyzed for the period 2000–2030 while for each scenario two policy variants are analyzed respectively with and without implementation of the biofuel directive. The results indicate that the area of semi natural vegetation, forest and High Nature Value farmland directly replaced by biofuel crops is small in all scenarios and differs little between policy variants. The direct effects of the directive on European land use and biodiversity therefore are relatively minor. The indirect effects of the directive on European land use and biodiversity are much larger than its direct effects. The area semi natural vegetation is found to be 3–8% smaller in policy variants with the directive as compared to policy variants without the directive. In contrast, little difference is found between the policy variants with respect to the forest area. The results of this study show that the expected indirect effects of the directive on biodiversity are much greater than its direct effects. This suggests that indirect effects need to be taken explicitly into account in assessing the environmental effects of biofuel crop cultivation and designing sustainable pathways for implementing biofuel policies.  相似文献   

19.
The human population is rising and the availability of terrestrial land and its resources are finite and, perhaps, not sufficient to deliver enough food, energy, materials and space. Thus, it is important to (further) explore and exploit the marine environment which covers no less than 71% of the earth's surface. The marine environment is very complex but can roughty be divided into two systems: natural (e.g. wild fishing) and human-made (e.g. artificial islands). In this study, characterization factors (CF) for natural and human-made marine systems were calculated in order to be able to assess the environmental impact of occupying marine surfaces, which was not possible so far in life cycle assessment. When accounting for natural resources while occupying one of these systems, it is important to consider the primary resources that are actually deprived from nature, which differs between the natural and human-made marine systems.In natural systems, the extracted biomass was accounted for through its exergy content, which is the maximum quantity of work that the system can execute in its environment. Reference flows for marine fish, seaweeds, crustaceans and mollusks were proposed and their correlated CF was calculated. For human-made systems, the deprived land resource is, in fact, the occupied area of the marine surface. Based on potential marine net primary production data (NPP), exergy based spatial and temporal CFs for ocean areal occupation were calculated. This approach was included in the Cumulative Exergy Extraction from the Natural Environment (CEENE) method which makes it the first life cycle impact assessment (LCIA) method capable of analyzing the environmental impact (and more specific the resource footprint) of marine areal occupation. Furthermore, the methodology was applied to two case studies: comparing resource consumption of on- and offshore oil production, and fish and soybean meal production for fish feed applications.  相似文献   

20.
Agroecology is the application of ecological concepts and principles to the design and management of sustainable agricultural systems. An agroecological approach to agriculture has special importance in the humid tropics where agricultural development and the preservation of tropical forests are most often in direct conflict. It is proposed that a more sustainable approach to development is needed, where agroecosystems depend on low external inputs, function more on the use of locally available and renewable resources, have benign impacts on the environment, and are based on the knowledge and culture of the local inhabitants. Examples of traditional agroecosystem management in Mesoamerica that can provide this basis are presented. The preservation of both biological and cultural diversity are integral to the long-term sustainable management of natural resources in the tropics.  相似文献   

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