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National conservation planning should operate with measures of biodiversity similar to those applied globally in order to harmonize national and international conservation strategies. Here we suggest quantitative measures which enable two criteria of the global biodiversity hotspots to be applied on a national level for 74 large countries, and show how these measures can be applied to map national biodiversity hotspots. The plant endemism criteria of global hotspots are captured by quantitative measures of endemism, which are approximately scale-independent and can be corrected to account for a country’s environmental conditions and conservation priorities. The flexible land use criteria for national biodiversity hotspots are defined from percentage of natural vegetation remaining in the global hotspots. The minimum-area-required approach is applied to define the borders of national biodiversity hotspots using data on vascular plants species richness. We show how national biodiversity hotspots can be mapped from the species-energy relationship for vascular plants using climate, topographical and land use data when spatial pattern of species richness is not known. This methodology to map national biodiversity hotspots from abiotic factors is applied to Russia as a case study. Three Russian biodiversity hotspots, North Caucasus, South Siberia and Far East were identified. The resulting hotspot maps cover national-scale environmental gradients across Russia and although they are also identified by Russian experts their actual geographical locations were hitherto unspecified. The large-scale national hotspots, identified for Russia, can be used for further fine scale and more detailed conservation planning.  相似文献   

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伴随着生物质能的快速发展,生物质能产业可持续性问题在全球范围内也日益引起高度重视。该文概述了国际上主要的生物质能可持续政策和标准,着重对其准则和指标进行了系统梳理,并就温室气体排放这一核心指标及不确定性加以分析。阐述了生物质能可持续准则和指标对生物质能产业政策的支持作用,并在此基础上提出了政策建议。中国应在《可再生能源法》和《生物质能发展规划》中明确提出可持续性要求,生物质能产业政策应与可持续性要求挂钩,可持续准则和指标的选取应兼具科学性和可操作性,应明确(greenhouse gas,GHG)排放核算方法学,并对最低排放要求的设置进行充分论证,同时,优先在航空生物燃料等领域构建生物质能可持续标准。  相似文献   

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全国土地利用总体规划目标的生态足迹评价研究   总被引:42,自引:2,他引:42  
该文采用生态足迹分析对全国土地利用总体规划的目标进行了评价。首先建立全国生态足迹及相关指标的时间序列(1996~2002年),认为2000年由于土地利用结构的控制不力直接导致中国人均生态供给较规划预期值少0.8%,并建立模型对全国土地利用总体规划纲要的远期目标(2010年)以及按照现在中国生态足迹强度发展的预期进行了规划的有无对比的足迹预测对比。计算结果表明,如果按照目前土地利用现状的趋势演变下去,预计到2010年,预期将比规划目标减少2.7%的生态供给,却增加1.53%的生态赤字。并就2001年的全国各省市土地利用现状做了全国生态足迹及其相关指标的区域差异分析。  相似文献   

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OBJECTIVE: Breast-feeding (BF) provides the ideal food for the healthy growth and development of infants. The prevalence of BF in Lebanon shows mixed results. The present study was the first large-scale, extensive survey on BF parameters in Lebanon that aimed to explore demographic, socio-economic and other fundamental issues associated with the initiation and duration of BF by Lebanese mothers.DESIGN: The survey was cross-sectional in design and administered over 10 months.SETTING: Information on all variables was collected from mothers at health centres.SUBJECTS: Two-stage sampling was conducted to select participants. A total of 1,000 participants were randomly selected. A consent form was provided to each participant. Data were collected from 830 of these.RESULTS: Almost all mothers were Lebanese, married and had given birth in a hospital. About a third stated that breast milk was the first food introduced after birth. Although 55.9% started breast-feeding their newborns within a few hours after birth, and 18.3% within half an hour, 21.2% replied that they initiated BF a few days after birth. Only 4.6% of the mothers replied that they never breast-fed their infant. Timing of initiation of BF was associated with the type of delivery (vaginal/Caesarean section) and hospital-related factors (rooming-in, night feedings and frequency of mother-infant interaction). Of the mothers who breast-fed exclusively beyond 6 months, 86.7% had initiated BF a few hours following delivery, while only 13.3% had initiated BF a few days later. Compared with the exceptionally high proportion of BF initiation, exclusivity of BF was low, dropping to 52.4% at 1 month. Exclusivity of BF was also associated with place of residence (urban/rural) and negatively associated with educational level of the mother. Duration of BF was inversely associated with the use of pain killers during delivery and maternal education. Rural mothers and those who practised exclusive BF maintained BF for a longer duration.CONCLUSION: Initiation rates of BF are very high in Lebanon but rates of exclusive BF are low and duration of BF is short. Future research targeting the factors associated with BF, with particular emphasis on exclusivity, is needed. For the 95.4% of mothers who initiated BF, an ecological perspective on intervention aimed at women and their social support system is required to improve duration and exclusivity.  相似文献   

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OBJECTIVES: To examine the contribution of the food service sector to the nutrient quality of the Irish diet, and to compare intakes at home, work and outside the home ('out') and within the subgroups of the out location (pub, deli, takeaway). DESIGN AND SETTING: Random sample of adults from the Republic of Ireland. Food intake data were collected using a 7-day food diary. Respondents recorded the location of every eating occasion determined by where the food was prepared rather than consumed. RESULTS: Intakes of energy, protein, fat and carbohydrate were significantly greater at home than at work or out (P<0.05). The intake of alcohol was significantly (P<0.001) greater out than at home or work. The percentage contribution of fat to energy was above the recommendations (33% of total energy and 35% of food energy) for both men and women at all locations, with the exception of the contribution of fat to total energy for men at the out location. Within the subgroups of the out location, the contribution of alcohol to total energy was greatest in pubs and the contribution of fat to both total and food energy was greatest in takeaways. Intakes of fibre and most micronutrients per 10 MJ of food energy were greater (P<0.05) at home than at work or out. CONCLUSION: Foods eaten outside the home contribute a disproportionately high level of fat intake and should be targeted in public health nutrition strategies.  相似文献   

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Many protected area (PA) systems have developed in response to socio-economic and aesthetic criteria and need to be modified to increase their conservation value. National gap analyses are an important step in describing and addressing this problem, so we sought to determine the representativeness of English PAs devoted to biodiversity conservation by using Natural Areas (NAs), elevation and PA boundary data. We found that National Nature Reserves (NNRs) and Sites of Special Scientific Interests (SSSIs) cover only 6.3% of England and are generally small, with respective median areas of 1.1 and 0.2 km2. The English PA system under-represents lowland areas and provides a median level of 2.5% protection for the NA types, with seventy nine per cent of NA types having less than 10% protection. Therefore, we suggest that England's PA system needs to be expanded, although this would probably entail modification of existing legislation to increase involvement by landowners. We also compare our results with previous appraisals that used species distribution record data and suggest that landscape-level analyses may give a more accurate and less positive assessment.  相似文献   

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There is considerable interest in the computation of national and regional soil carbon stocks, largely as the result of the provisions of the Kyoto Protocol. Such stocks are often calculated and compared without proper reference to the uncertainties induced by different analytical methodologies. We illustrate the nature and magnitude of these uncertainties with the present soil organic carbon (SOC) study in Belgium. The SOC recovery of the Walkley‐Black method was investigated based on a database of 475 samples of silt loam and sandy soils, which cover different soil depths and vegetation types in northern Belgium. The organic carbon content of the soil samples was measured by the original Walkley‐Black method and by a total organic carbon analyser. The recovery was computed as the ratio of these two results per soil sample. Land use, texture and soil sampling depth had a significant influence on the recovery as well as their three‐way interaction term (land use × texture × sampling depth). The impact of a land use, texture and sampling depth dependent Walkley‐Black correction on the year 2000 SOC inventory of Belgium was determined by regression analysis. Based on new correction factors, the national SOC stocks increased by 22% for the whole country, ranging from 18% for cropland to 31% for mixed forest relative to the standard corrected SOC inventory. The new recovery values influenced therefore not only C stocks in the year 2000, but also the expected SOC change following land use change. Adequate correction of Walkley‐Black measurements is therefore crucial for the absolute and comparative SOC assessments that are required for Kyoto reporting and must be computed to take into account the regional status of soil and land use. ‘Universal’ corrections are probably an unrealistic expectation.  相似文献   

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A three-year field trial on an upland loessial soil (Belmont silt loam) in New Zealand investigated the effects of ripping, application of fertilizer N and grazing management on the recovery of some physical, chemical and biochemical properties of soil and pasture productivity following removal (mining) of topsoil. Removing the top 31 cm of soil by mining (all of the A horizon and part of the AB horizon) also removed most of the soil's labile organic matter fractions, and to a lesser extent its total organic matter. After three years, the microbial C and mineralizable N in the 0–10 cm depth of mined soil had reached 65 and 62 per cent of the corresponding levels in unmined soil. Ripping to a depth of 30 cm, application of fertilizer N and lenient grazing of the pasture failed to enhance the recovery of soil fertility. A soil sampling depth of 20 cm provided a reasonable basis to assess the microbial biomass and potential fertility. Pasture productivity was, on average, 30 per cent lower on mined land than on unmined land over the first three years after mining. Application of N proved uneconomic in terms of farm production, although a good pasture response to N fertilizer was obtained. The results from this and related trials are summarized as a series of recommendations for the monitoring and regulation of topsoil mining. An incentive regime is also recommended to encourage land owners and/or topsoil miners to use successful restoration techniques on topsoil-mined land. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   

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OBJECTIVES: To analyse the temporal distribution of the intake of cereal and dairy products in the Republic of Ireland. DESIGN: The North/South Ireland Food Consumption Survey established a database of habitual food and drink consumption using a 7-day food diary. The database also recorded the time and day of food consumption. Mean intakes of cereal and dairy products were calculated for time of the day and day of the week. RESULTS: At the weekend, the percentage of consumers decreased for nearly all cereal and dairy products. White bread, total cereals, full-fat milk and total dairy intakes were significantly lower at the weekend (P<0.01) compared with weekdays. Intakes of cereal and dairy products over time of the day showed clear mealtime or snacking patterns when the number of consumers was controlled for. White bread, wholemeal bread, total cereals, full-fat milk, reduced-fat milk and total dairy intakes showed mealtime peaks for morning, afternoon and evening. When examined by tertile of intake, tertile of percentage energy from fat and tertile of fibre intake, intakes of cereal and dairy products over time of the day and day of the week were similar to trends described above, regardless of the tertile. CONCLUSIONS: Temporal analysis of the intakes of cereal and dairy products did not reveal any unusual trends in this population. However, the significant methodological issues raised in this paper will be of benefit to other aspects of research in this area.  相似文献   

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我国水力侵蚀抽样调查方法   总被引:10,自引:0,他引:10  
水力侵蚀普查是2010-2012年第1次全国水利普查水土保持情况普查的重要内容之一,抽样调查是本次水力侵蚀普查的主要方法.野外抽样调查单元依据不同侵蚀类型区和各省份实际情况相结合的原则布设:在全国按统一网格布局,按一定密度抽样,获得野外调查单元的位置;以第4层网格(1 km×1 km)为基础,在平原区以1 km×1 km网格、在丘陵区和山区以0.2~3.0 km2的小流域作为野外调查单元.综合分析降雨、地形、土地利用和水土保持措施等影响水力侵蚀的因子,利用中国土壤流失方程来评价水力侵蚀强度,获得水力侵蚀的分布、面积与强度,为国家水土保持与生态建设提供决策依据.水力侵蚀抽样调查方法研究对全面调查和科学评价水力侵蚀现状、发展趋势和预测预报具有重要意义.  相似文献   

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The Western diet contains large quantities of oxidized lipids, because a large proportion of the food in the diet is consumed in a fried, heated, processed, or stored form. We investigated the reaction that could occur in the acidic pH of the stomach and accelerate the generation of lipid hydroperoxides and cooxidation of dietary vitamins. To estimate the oxygen content in the stomach after food consumption, oxygen released from masticated bread (20 g) into deoxygenated water (100 mL) was measured. Under these conditions, the oxygen concentration rose by 250 microM and reached a full oxygen saturation. The present study demonstrated that heated red meat homogenized in human gastric fluid, at pH 3.0, generated hydroperoxides and malondialdehyde. The cross-reaction between free radicals produced during this reaction cooxidized vitamin E, beta-carotene, and vitamin C. Both lipid peroxidation and cooxidation of vitamin E and beta-carotene were inhibited at pH 3.0 by red wine polyphenols. Ascorbic acid (44 mg) at a concentration that represented the amount that could be ingested during a meal inhibited lipid peroxidation only slightly. Red wine polyphenols failed to prevent ascorbic acid oxidation significantly but, in conjunction with ascorbic acid, did inhibit lipid peroxidation. In the presence of catechin, a well-known polyphenol found in red wine, ascorbic acid at pH 3.0 works in a synergistic manner preventing lipid peroxidation and beta-carotene cooxidation. The present data may explain the major benefits to our health and the crucial role of consuming food products rich in dietary antioxidants such as fruits, vegetables, red wines, or green tea during the meal.  相似文献   

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