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与人们往往吃太多动物产品的发达国家不同,非洲撒哈拉以南地区的人口多半吃太少这种类型的食品来获得良好营养.非洲撒哈拉以南地区预计的牲畜需求量增加,将对食品保障和贫困缓解产生重要影响.牲畜对达到农业生产率和可持续性目标来说是至关重要的.作为农作物种植-牲畜养殖混合体系的组成部分,它们在环境无害生产体系的发展中发挥决定性作用.在牲畜产生负面环境影响的地方,这可能是由于政策失真和执法不力所致.  相似文献   
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与人们往往吃太多动物产品的发达国家不同,非洲撒哈拉以南地区的人口多半吃太少这种类型的食品来获得良好营养.非洲撒哈拉以南地区预计的牲畜需求量增加,将对食品保障和贫困缓解产生重要影响.牲畜对达到农业生产率和可持续性目标来说是至关重要的.作为农作物种植-牲畜养殖混合体系的组成部分,它们在环境无害生产体系的发展中发挥决定性作用.在牲畜产生负面环境影响的地方,这可能是由于政策失真和执法不力所致.  相似文献   
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Since 1991, there have been significant changes in utilization of feed resources in the Ethiopian highlands: while use of communal grazing lands and private pastures has declined, use of crop residues and purchased feed has increased. In addition, although use of animal health services and adoption of improved livestock breeds and modern management practices have increased, ownership of various types of livestock has declined. Rapid population growth has contributed most to the declining trends in grazing resources and ownership of livestock, showing the negative effects of increasing pressure on already degraded resources in the Ethiopian highlands. Land redistribution, increased participation in credit and extension programs targeting livestock, and improvement in access to markets, on the other hand, have had significant positive impacts on adoption of improved livestock technologies and ownership of livestock. Thus, reducing population growth and improving access to markets and credit and extension programs targeting livestock can enhance the role of livestock in improving food security and reducing poverty, especially in the mixed crop-livestock farming systems as exist in the East African highlands.  相似文献   
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Global consumption, production, and trade of livestock products have increased rapidly in the last two decades and are expected to continue. At the same time, safety concerns regarding human and animal disease associated with livestock products are increasing. Efforts to increase public health safety standards aimed at legitimately reducing the risks of human and animal disease have focused internationally on standards to regulate the movement of livestock products. There is concern, though, that measures to regulate these standards internationally, such as the WTO SPS measures that in part aim to open international markets, may marginalize small-scale poor producers. The cycle of poverty they are trying to escape through livestock production may, in fact, widen, leading to increased global poverty, malnutrition, and disease. Developing and developed nations alike should be concerned with public and private efforts to address appropriate food safety policies to reduce the likelihood of this effect. Analysis of the impact on small-scale livestock farmers is needed, as well as solutions that consider joint public and private sector initiatives. Costly farm to table tracking systems are not an option, but locally orchestrated vertically integrated systems may have merit in reducing food safety risks and in providing small-scale farmers with increased access to markets, locally and internationally. Increased scientific and technical capacity, and training of WTO officials from developing nations is also needed.  相似文献   
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Stakeholders in plantation forestry are increasingly aware of the importance of the ecosystem services and non-market values associated with forests. In New Zealand, there is significant interest in establishing species other than Pinus radiata D. Don (the dominant plantation species) in the belief that alternative species are better suited to deliver these services. Significant risk is associated with this position as there is little objective data to support these views. To identify which species were likely to be planted to deliver ecosystem services, a survey was distributed to examine stakeholder perceptions. Stakeholders were asked which of 15 tree attributes contributed to the provision of five ecosystem services (amenity value, bioenergy production, carbon capture, the diversity of native habitat, and erosion control/water quality) and to identify which of 22 candidate tree species possessed those attributes. These data were combined to identify the species perceived most suitable for the delivery of each ecosystem service. Sequoia sempervirens (D.Don) Endl. closely matched the stakeholder derived ideotypes associated with all five ecosystem services. Comparisons to data from growth, physiological and ecological studies demonstrated that many of the opinions held by stakeholders were inaccurate, leading to erroneous assumptions regarding the suitability of most candidate species. Stakeholder perceptions substantially influence tree species selection, and plantations established on the basis of inaccurate opinions are unlikely to deliver the desired outcomes. Attitudinal surveys associated with engagement campaigns are essential to improve stakeholder knowledge, advancing the development of fit-for-purpose forest management that provides the required ecosystem services.  相似文献   
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In Southeast Asia, elasmobranchs are particularly threatened. We synthesized knowledge from the peer-reviewed and gray literature on elasmobranchs in the region, including their fisheries, status, trade, biology, and management. We found that 59% of assessed species are threatened with extinction and 72.5% are in decline; rays were more threatened than sharks. Research and conservation is complicated by the socioeconomic contexts of the countries, geopolitical issues in the South China Sea, and the overcapacity and multispecies nature of fisheries that incidentally capture elasmobranchs. The general paucity of data, funds, personnel, and enforcement hinders management. Reduced capacity in the general fishery sector and marine protected areas of sufficient size (for elasmobranchs and local enforcement capabilities) are among recommendations to strengthen conservation.  相似文献   
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