生物资源在农业减灾中的开发利用前景

论述了以水、旱为主的气象灾害和农作物病、虫、草、鼠所致的生物灾害对农业生产的灾害性影响, 同时阐述了有效开发利用生物资源是防止和减轻农业灾害的有效途径, 提出了加强生物资源的开发利用研究内容     

关于中国可持续农业问题的研究

农业可持续发展是国家可持续发展的根本保证和优先领域,实现农业可持续发展必须建立可持续农业。本文认为,高科技生态农业是中国可持续农业的唯一战略选择和最终出路。为实现这一战略选择,在继续贯彻实施计划生育和环境保护两个基本国策的同时,必须调整现有的农业结构和资源管理模式,制定可持续利用的资源管理政策,发展以生态农业为基础、以高新农业技术为手段的高科技生态农业。     

Migrant land rights reception and 'clearing to claim' in sub-Saharan Africa: A deforestation example from southern Zambia

The relationship between migration and deforestation in the developing world continues to receive significant attention. However beyond direct population increase, the precise mechanisms that operate within the intersection of migrant/host land rights remain largely unexamined. Where migrants are provided with land and rights by the State and/or local communities, how such rights are perceived by the migrants is of primary importance in their interaction with land resources, and in aggregate it impacts the development opportunities and environmental repercussions of migration. The authors analyze the operative aspects of land rights reception (as opposed to provision) by migrant populations, and the relationship between this reception and deforestation. The article examines a case in Zambia to analyze how tenurial constructs, emerging from the way rights are perceived by migrants, lead to the continued clearing of areas much larger than needed for cultivation, even when the arrangement appears counter‐productive in terms of land rights provision and labour allocation. While valuable policy efforts have focused on providing resource rights to migrants, how such rights are received and the relationship of this reception to resource management needs greater policy attention.     

Rice versus fish revisited: On the integrated management of floodplain resources in Bangladesh

Disproportionately little attention has been paid to the dry season trade‐off between rice and (inland capture) fish production on the floodplains of Bangladesh, compared to the same trade‐off during the flood season. As the rural economy grows increasingly dominated by dry‐season irrigated rice production, and floodplain land and water come under ever‐increasing pressure during the dry winter months, there is an urgent need to focus attention on these dry months that are so critical to the survival and propagation of the floodplain resident fish, and to the poor people that depend on these fish for their livelihood. This article examines three important dry‐season natural resource constraints to floodplain livelihoods in Bangladesh, and finds a common factor at the heart of all three: rice cultivation on lands at low and very low elevations. The article articulates the system interlinkages that bind these constraints and the long‐run trend towards irrigated rice cropping on lower‐lying lands, and suggests a management approach based on locally tailored strategies to arrest this trend. Apart from its direct relevance to the floodplains of Bangladesh, which support more than 100 million people, these lessons have relevance for river floodplain systems elsewhere in the developing world, notably the Mekong Delta.     

区域自然灾害系统基本单元研究-Ⅱ:应用部分——湖南省综合农业灾情区域分异规律

本文应用灾害系统基本单元理论,以湖南省农业自然灾害为例,在地理信息系统支持下,将湖南省农业自然灾害系统划分为３２５２４个基本单元。进而,以民政部１９７８～１９９３年农业灾情统计数据为标准,通过多因子逐步回归的方法,建立了反映湖南省多年平均状况的五种主要农业灾害灾情模型。最后,以灾害基本单元为最小空间分异单位,对综合农业灾情分异规律进行了探讨,并首次提出了基于自然单元的湖南省综合农业灾情的分异规律首先是受地势控制的东西分异的主要结论。     

Macroinvertebrate Community Structure Along the Longitudinal Gradient of an Agriculturally Impacted Stream

/ Lapwai Creek, an agriculturally impacted stream in northern Idaho, was sampled seasonally over a two-year period to determine if macroinvertebrate community composition changed along the longitudinal gradient and if changes followed predictions of the river continuum concept. Possible relationships between changes in food resource availability and community structure were also examined. Benthic invertebrates were collected at eight locations along the longitudinal gradient of Lapwai Creek using a Hess sampler. Random skewer analysis suggested there was no longitudinal gradient for either number of individuals or functional feeding group composition. Cluster analysis revealed that all locations, excluding a site receiving outflow from a small, eutrophic reservoir, had a similar community structure, further suggesting that invertebrate community composition remained consistent along the longitudinal gradient of the stream. The community was dominated at all sites, excluding the site below the reservoir, by functionalgrazers. Shredders were rare throughout Lapwai Creek, even in areas where healthy riparian vegetation still remained. Studies of other streams within the drainage basin show that many species found in the upper reaches of these streams, where agricultural impacts are low, were absent throughout the length of Lapwai Creek. Data collected concurrently with macroinvertebrates indicated that the input, storage, and transport of particulate organic matter was low throughout the stream, whereas periphyton abundance was high. The absence of longitudinal changes, despite flowing through three distinct geomorphological regions, and the grouping of all sites except one by cluster analysis for both dominant taxa and functional feeding groups suggest that agricultural alteration has influenced community structure of Lapwai Creek, resulting in a relatively homogeneous assemblage of macroinvertebrates capable of tolerating agricultural nonpoint source pollution. Additional support for this hypothesis is the high abundance of one food source, periphyton, and the small quantities of terrestrially derived organic matter. The abundance of the former and the rarity of the latter can be attributed to alteration of the drainage basin resulting from agricultural activities through inputs of fertilizers that generated high nutrient concentrations and the removal of riparian vegetation to clear more land for agriculture and provide increase access to the stream.KEY WORDS: Agriculture; Longitudinal patterns; Macroinvertebrates; Nonpoint source; River continuum     

The use of computer models in planning upland land use

The British Ecological Society has suggested that computer‐based techniques could be used in the coordination of policies across different land uses in upland planning. This paper looks briefly at one such technique — a linear programming model — and describes its use at a regional scale for the Sedburgh area in north‐west England. The paper concludes with consideration of why such models are not in more common use.     

Hurricanes and agriculture: Losses and remedial actions*

Hurricanes cause serious and long-term damage to the Agricultural sectors of Caribbean countries. Bananas and tree crops are defoliated, snapped or uprooted and food crops may be flooded or washed away. Recovery takes time and money as both the production bases and the infrastructure are damaged or destroyed. National economies do not have the resources to expedite recovery without aid. An account is given of the actions taken to estimate losses and prepare rehabilitation plans after Hurricanes David (1979) in Dominica and Allen (1980) in St. Lucia and St. Vincent. The implementation of funding agency-assisted agricultural rehabilitation programmes is also described. Some steps that farmers can take to reduce loss of food are suggested.     

秦皇岛市农业可持续发展研究

本文首先分析了可持续农业的基本理论,然后对秦皇岛市农业可持续发展面临的主要问题进行了较为深入的分析,在此基础上提出了秦皇岛市农业可持续发展的主要措施。