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新世纪以来国内外生态农业综合评估研究进展   总被引:3,自引:0,他引:3  
在梳理了新世纪以来国内外文献的基础上,对生态农业的概念进行了溯源与辨析,系统总结了国内外学者对生态农业综合评估指标选取和指标体系建立的主要思路,将现有评估体系归纳为EES框架及其拓展和PSR、DSR模型两类,对评估研究所采用的主要指标进行了频度统计、讨论和中外对比。概括了当前研究中采用的权重确定与综合评估的主要方法并进行了优缺点比较。从农业特征、空间尺度、时间跨度等角度对国内外已有的实证研究进行了分类与总结。研究比较发现,国内生态农业评估在实际指标的选取中,往往将数据易得性放在首要位置,而缺乏对指标之间内在逻辑联系和指标合理性、有效性的审视,指标体系构建缺乏代表性和概括性。此外,在对生态概念的理解上,现有评估体系对农业生产环节的生态影响挖掘的并不深刻,对石油消耗、电力消耗尤其是碳排放等重要的间接生态影响存在遗漏。最后,针对现有农业生态评估存在的问题,研究提出六方面的建议:1鉴于全球气候变化影响的广泛和深入,考察我国和各地区的生态农业需要具有全球视野,应当将农业碳汇/碳源的测度和评估纳入到生态农业综合评估体系中;2评估时应当把握好农业生产效率的提升与生态环境保护两者之间的关系;3重视对农业生态模式和类型的辨识;4以我国农业发展阶段特征作为指标体系设计的基石,避免直接移植国外文献中的指标体系;5注重综合评估的案例导向性,并结合多源异构数据的优势来提高评估准确度;6注重对生态农业发展和变迁情况的长期性、复杂性和综合性的考量,提高评估的空间尺度和时间跨度。  相似文献   

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21世纪以来中国产业扶贫研究脉络与主题谱系   总被引:1,自引:0,他引:1  
反贫困历来是发展研究中的最重要议题之一,尤其是进入21世纪以来,产业扶贫已日趋成为具有中国特色的反贫工作重心任务,受到学界和社会的热切关注,因此有必要对其研究脉络与热点主题等内容进行深入探索,以更好地促进产业扶贫实践的发展。本研究以2000—2015年间CNKI数据库收录的1 982篇产业扶贫研究的期刊论文为样本,采用文献计量分析法和可视化知识网络分析工具Cite Space,首先对中国产业扶贫研究总体现状进行了概述,然后着重分析了产业扶贫研究历经的四个演进阶段:初创期、探索期、爆发期和深化期,并描述了研究的整体发展脉络所沿着的四条轨迹,即产业扶贫主体由政府主导逐渐演变为政府主导、市场力量和社会参与并重;扶贫对象由农村贫困地区和人口逐步转向城市贫困人口,农村和城市扶贫两者并重;扶贫渠道由财政资金扶持逐步扩散到科技扶贫、智力扶贫、旅游扶贫等多元化方式;扶贫思路由农村推进向城市扶贫过渡,再到协调区域发展的精准扶贫战略。在此基础上挖掘和探讨了当前研究的热点主题,包括产业扶贫的发展历程、内涵与理论基础、模式与机制、现实困境与对策,以及经济效应等五个方面。最后指出当前研究成果在理论深度与体系构建、实践模式提炼、研究视角和地域、实证研究方法等方面存在不足,并提出了未来重点研究方向需要从高度重视产业扶贫与精准扶贫和参与式治理之间的内在逻辑,加快推进产业扶贫的本土化特色研究,以及鼓励跨学科视角的研究、注重规范研究与实证研究的协同三大方面展开探索。  相似文献   

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We present climate change projections and apply indices of weather extremes for the Mediterranean island Cyprus using data from regional climate model (RCM) simulations driven by the IPCC A1B scenario within the ENSEMBLES project. Daily time-series of temperature and precipitation were used from six RCMs for a reference period 1976–2000 and for 2026–2050 (‘future‘) for representative locations, applying a performance selection among neighboring model grid-boxes. The annual average temperatures of the model ensemble have a ±1.5°C bias from the observations (negative for maximum and positive for minimum temperature), and the models underestimate annual precipitation totals by 4–17%. The climatological annual cycles for the observations fall within the 1σ range of the 6-model average, highlighting the strength of using multi-model output. We obtain reasonable agreement between models and observations for the temperature-related indices of extremes for the recent past, while the comparison is less good for the precipitation-related extremes. For the future, the RCM ensemble shows significant warming of 1°C in winter to 2°C in the summer for both maximum and minimum temperatures. Rainfall is projected to decrease by 2–8%, although this is not statistically significant. Our results indicate the shift of the mean climate to a warmer state, with a relatively strong increase in the warm extremes. The precipitation frequency is projected to decrease at the inland Nicosia and at the coastal Limassol, while the mountainous Saittas could experience more frequent 5–15 mm/day rainfall. In future, very hot days are expected to increase by more than 2 weeks/year and tropical nights by 1 month/year. The annual number of consecutive dry days shows a statistically significant increase (of 9 days) in Limassol. These projected changes of the Cyprus climate may adversely affect ecosystems and the economy of the island and emphasize the need for adaptation strategies.  相似文献   

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The ideas of the evolutionary ecology of the 20th century and its modern conceptual space are considered with regard to new knowledge of the contents of population and evolutionary synecology. The article proposes (1) a population cenotic approach to analyzing the covariation of cenopopulations of sympatric species and taxocenes in space and historical time; (2) an approach to assessing the intragroup morphological disparity in cenopopulations of sympatric species and taxocenes as a measure of morphogenetic stability. Consideration is given to experimental evolutionary ecology as a particular methodological area. Prospects for the formation of evolutionary ecology as an interdisciplinary applied science are discussed in view of the necessity of predicting regional biocenotic crises and rapid coevolutionary changes in biotic communities in a technogenic environment against the background of predicted unfavorable trends of climate changes.

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7.
The 21st century is referred to as a "century for cities"or "era for cities", and China has also speeded up its processof urbanization, which will bring massive influence to theeconomic development of the country and also to theworld. Joseph E. Stiglize, a winner of The Nobel Prize onEconomy, said that (the urbanization in China and thedevelopment of high technologies in the United Stateswill be two major subjects with a profound effect to thedevelopment of all mankind in the 21st century) …  相似文献   

8.
Abstract

This paper begins by analysing the mutual influence between international trade and the environment, and then proceeds to explore the environment and trade conflicts. On the basis of sustainable development theories and the above discussion, the article suggests taking sustainable trade as a solution to the existing conflicts. This paper aims to find the way to strike a balance between international trade and environment based on the present situation in China.  相似文献   

9.
Quantitative research on land use and land cover (LUC) in Africa usually addresses the second half of the twentieth century, by using remote sensing data. Terrestrial photographs, which are available since 1868 in Ethiopia, are seldom used in a quantitative way. This paper presents a methodology that allows to produce land use and land cover (LUC) maps on the basis of old terrestrial photographs. Therefore, land use and land cover was investigated on historical and present-day photographs, and these interpretations were warped to the horizontal plane of the map. The resulting maps allow to gain better insights into LUC changes over a period of 140 years. The results show that woody vegetation increased strongly, together with an increase in built-up area. This occurred especially at the expense of bushland. The study validates pervious findings and shows that improved land management strategies in one of the world’s most degraded areas can lead to environmental rehabilitation.  相似文献   

10.
A major component of climate change is a manifestation of changes in air quality. This paper explores the question of air quality from the climate change modelling perspective. It reviews recent research advances on the cause-effect relationships between atmospheric air composition and climate change, primarily based on the Intergovernmental Panel on Climate Change (IPCC) assessment of climate change over the past decade. There is a growing degree of confidence that the warming world over the past century was caused by human-related changes in the composition of air. Reliability of projections of future climate change is highly dependent on future emission scenarios that have been identified that in turn depend on a multitude of complicated interacting social-economic factors. Anticipated improvements in the performance of climate models is a major source of optimism for better climate projections in the future, but the real benefits of its contribution will be closely coupled with other sources of uncertainty, and in particular emission projections.  相似文献   

11.
Increasingly, emphasis is being placed on the role of indigenous or locally crafted natural resources management systems in sustainable natural resources management. While it is generally agreed that their potential to sustain and protect natural ecosystems exists in large measure, such systems are increasingly facing diverse internal and external pressures that threaten their viability. These pressures include demographic and economic change, land privatisation policies, renewable energy investment projects and large-donor-driven livelihood projects. Such pressures and their complexity raise the need to understand how local communities organise to protect resources they collectively value in the face of both internal and external pressures. Based on empirical data collected through interviews, participant observations, focus group discussions and a questionnaire survey conducted with local level actors in Shisholeka village of Central Zambia, this paper shows how local actors, in the absence of state support, react to internal and external pressures to develop robust and locally suited governance and institutional arrangements that best suit their interests in order to sustain their resource base.  相似文献   

12.
Since the last decade the WHO Collaborating Centre for Air Quality Management and Air Pollution Control, Berlin, Germany, operates a quality assurance and control (QA/QC) programme on air quality monitoring in the WHO European Region. As main activity Intercomparison workshops have been established for air monitoring network laboratories on a regular basis to harmonise air quality measurements, analysis and calibration techniques. 36 air hygiene laboratories of public health and environmental institutions of 24 countries participated in twelve Intercomparisons between 1994 and 2004. The majority was carried out for NO, NO(2), SO(2) and O(3). The results were predominantly satisfactory for automatic methods. The results of manual methods were mainly in a good, and for several concentration levels partly very good accordance with the data obtained by the monitors.  相似文献   

13.
Smallholder agriculture in the Central Andes of Peru is based to large extent on rainfed cropping systems, is exposed to climatic risks and is expected to respond sensitively to increasing temperatures and shifts in the precipitation regime. Here, we examine the potential implications of early twenty-first century climate change scenarios for the cultivation of potato, maize, wheat, barley and broad bean, five annual crops that account for 50 % of the cultivated area in the Department of Cusco and Apurímac and provide the dietary backbone for a large share of the local population. The scenarios disclose a regionally coherent increase in temperature of the order of 1 °C but overall only moderate changes in growing season precipitation by 2030. A simple crop model is used to assess the effects of these changes on crop phenology and development. The results show earlier harvest dates, shorter cropping seasons and, in a few cases, a slightly higher risk of planting failure in the near future. This suggests that a better understanding of changes in the precipitation regime at the onset of the cropping season is required to evaluate short-term needs and possibilities for adaptation. However, as the scenarios are highly uncertain, these conclusions should be verified.  相似文献   

14.
For centuries famine arose as a seemingly endless series of acute, regional and unanticipated events; it has transformed into a phenomenon, global in scale and continuous in nature. Half the world’s human population perpetually suffers some form of malnourishment, from either a scarcity of calories, protein or micronutrients or from a combination of these. Sheer population size has rendered the scale of suffering unprecedented. Perpetual famine has emerged during an era of abundant and relatively inexpensive soil, water and energy resources, improving crop yields, and a benign climate. However, the twentieth century trends of resource degradation, diminishing growth in crop yields and a warming atmosphere will likely continue, latently and perhaps synergistically impacting agricultural production, and therefore, threatening food security in the twenty-first century. Assuming some proportional relationship between food security and these resources, famine is here projected to greatly increase in the coming decades, severely impacting billions of people.  相似文献   

15.
Traditional environmental knowledge (usually imparted orally) is being lost from many regions of the world, requiring novel forms of transmission if this situation is to be redressed. Loss of this knowledge may be a significant contributory factor towards ecological decline. Undoubtedly, disruption to ecosystems and societies that depend on these has impacted on traditional land management practices, with negative ramifications for biodiversity. From an environmental perspective, scientists in northern Australia need to understand traditional Aboriginal methods of ‘caring for country’, such as burning regimes, so that these can be incorporated into strategies today for maintaining Australia’s rich biodiversity. However, information exchange should be two-way: as well as learning from local people, science can in turn benefit people who may have little experience of, for example, invasive species. The challenge is how can the complexity of biological knowledge from within different ontologies be represented and integrated in a way that it can be of use to scientists and local people, in order to ensure a sustainable future? The main aim of this study was to record existing local knowledge of biodiversity for the community of Aurukun (far north Queensland), integrating this knowledge with scientific data, while giving parity to both knowledge systems and protecting intellectual property rights. A cross-cultural collaboration between community members and ethnobiologists resulted in development of the Aurukun Ethnobiology Database. An interdisciplinary approach was taken to effectively model autochthonous biological knowledge and scientific data to create a database with a number of practical applications.  相似文献   

16.
The structure of Siberian stone pine (Pinus sibirica Du Tour.) and Siberian larch (Larix sibirica Ledeb.) stands and specific features of their formation have been studies in the forest-tundra ecotone on the North Chuya Ridge (2235–2475 m a.s.l.). Changes in the structure of these stands along the transition from the upper boundary of closed forests to the high-mountain tundra have proved to have an ambiguous pattern. Both tree species form mixed clusters of similar-aged trees in the lower part of the ecotone but grow singly, in scatters, in its upper part. The formation of conifer stands (tree clusters) in the lower part of the ecotone, on the slopes of the Aktru River valley, began during climate warming in the second half of the 19th century. The expansion of confers to its upper part took place markedly later, in the early 20th century (Siberian larch) or even in the 1930s (Siberian stone pine).  相似文献   

17.
Assessment of airborne organophosphorus pesticides in houses of young children (1-6 years old) and childcare facilities was conducted following pesticide applications in an agricultural community in Japan. Trichlorfon and fenitrothion, applied in two separate periods, were frequently detected from outdoor and indoor air. Dichlorvos, the primary degradation product of trichlorfon, was also detected after the application of trichlorfon. Both the outdoors and indoor concentration of applied pesticide were shown to increase with decreasing distance from the pesticide-applied farm. Indoor concentration of these pesticides significantly correlated with outdoor concentration (p=0.001 for trichlorfon and p=0.001 for fenitrothion), indicating infiltration of applied pesticide inside. Ratio of indoor to outdoor concentration (I/O ratio) of fenitrothion was higher for houses with windows open during the application than those with closed windows (median value: 0.74 vs. 0.16, p=0.003). However, a similar trend was not observed for trichlorfon as well as dichlorvos in the first period. Dichlorvos was found to have a higher I/O ratio than trichlorfon during the period, and clear correlation between indoor concentrations of dichlorvos and those of trichlorfon suggested increased decomposition of trichlorfon in the indoor environment. Daily inhalation exposure estimated by using the fixed measurement data and time-activity questionnaire ranged from 0 to 35 ng/kg/day for trichlorfon, from 0 to 26 ng/kg/day for dichlorvos, and from 0 to 44 ng/kg/day for fenitrothion. Median inhalation exposure from indoor air accounted for 74%, 86.3%, and 45% of the daily inhalation exposure, respectively. For kindergarteners or nursery school children, inhalation exposure at childcare facilities was comparable with or more than that at home, indicating that pollution level at childcare facilities had potential of high impact on children's exposure. Estimated daily inhalation exposures were inversely correlated to the proximity of their activity location to the pesticide-applied farm.  相似文献   

18.
Since the last decade the WHO Collaborating Centre for Air Quality Management and Air Pollution Control, Berlin, Germany, operates a quality assurance and control (QA/QC) programme on air quality monitoring in the WHO European Region. As main activity Intercomparison workshops have been established for air monitoring network laboratories on a regular basis to harmonise air quality measurements, analysis and calibration techniques. 36 air hygiene laboratories of public health and environmental institutions of 24 countries participated in twelve Intercomparisons between 1994 and 2004. The majority was carried out for NO, NO2, SO2 and O3. The results were predominantly satisfactory for automatic methods. The results of manual methods were mainly in a good, and for several concentration levels partly very good accordance with the data obtained by the monitors.  相似文献   

19.
China is a country with multinationalities. The political, social, and economic significances of the economic and social development in the minority areas have a very close connection with the modernization of the whole China's politics, society, and economy. The movement of minority rural migrants to the urban areas or to the nonagricultural industries is one of the key issues in the economic and social development in the minority rural areas. The rural population migration in the minority areas was taken as the important research topic, hoping to be of benefit to the deeper understanding of the current migration movement in China.  相似文献   

20.
Previous studies have suggested that a segment of human disease may be attributable to environmental exposures. These may include exposure to chemicals released from a broad range of natural and man-made sources. The purpose of this study was to develop the sampling methodology and prepare a preliminary database on the presence of various organic chemicals in environmental media in two South Texas counties bordered by the Rio Grande River. A third county, located approximately 150 miles north of the Rio Grande River, was also sampled. The South Texas counties were the focus of study due to an increased incidence of anencephalic births in recent years. The environmental media that was sampled included surface water and sediment from the Rio Grande River and irrigation canals, as well as soil from adjacent cropland and pastures. Samples were collected using United States Geological Survey (USGS) quadrangle maps (7.5'; 1:24,000 scale) to identify the area of interest. At least one sampling location was established in each quadrangle. A pond sampler was used for the collection of surface water samples, while soil was collected with a stainless steel trowel. Sediment samples were collected directly in a glass jar. Solid samples were extracted in a soxhlet extractor using methylene chloride. Organic chemicals were concentrated from water samples on a Sep-Pak cartridge and the organics eluted with methanol/acetonitrile. Extracts were analyzed using GC-MS. All of the surface water samples contained aliphatic hydrocarbons and plasticizers, while soil samples contained aliphatics, plasticizers, pesticides, and industrial estrogens. Specific chemicals detected in environmental samples included atrazine and benzene dicarboxylic acid. Contaminant levels in sediments were generally higher than were detected in other media. The results demonstrate the broad variability of contaminant types and concentrations in environmental samples. Although this study presents only a very preliminary characterization of a large area of South Texas, the data indicate a number of pesticides and xenobiotic estrogens that were identified in environmental samples. Additional data providing more details of spatial and temporal distribution of contaminants as well as wildlife studies are needed.  相似文献   

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