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1.
Studies on the reproductive biology of seabirds on Talan and Umara islands in 1987–1999 showed that the diet of nestlings and reproductive success of the tufted puffin (Lunda cirrhata) and horned puffin (Fratercula corniculata) considerably varied in different colonies. This was determined by differences in the hydrologic characteristics of water areas and the state of food resources in Taui Bay (the northern Sea of Okhotsk). The reproductive success of tufted puffins was higher on Umara Island due to more favorable environmental conditions and relatively stable food resources in Odyan Bay. The parameters of reproductive success and the nestling diet in tufted and horned puffins from Talan Island differed considerably. The survival of nestlings was always higher in horned puffins, which was related to some characteristics of their feeding ecology.  相似文献   

2.
A comparison of two Siberian moth populations from the Altai Republic (feeding on Siberian fir) and the Tyva Republic (feeding on Siberian larch) has revealed no differences between them with respect to ecophysiological parameters of larval growth and feeding on needles of the same conifer species under laboratory conditions. The index of appropriateness of food plants for the larvae from both populations decreases in the series larch > fir > spruce > pine. The age-related dynamics of parameters characterizing the feeding and growth of larvae are independent of the population to which the insects belong.  相似文献   

3.
The Macrolepidoptera fauna of the Urals, from the southern to the northern boundary of the forest zone (i.e., from the forest–steppe of the Southern Urals to the forest–tundra of the Polar Urals) has been analyzed. It has been demonstrated that the proportion of Lepidoptera feeding on woody plants, including evergreens, increases in this direction. Among the Heterocera, the proportion of species feeding on graminoids decreases; in the Polar Urals, none of these species is specialized. The food spectrum is particularly variable in noctuids and almost invariable in geometrids and Rhopalocera. It is assumed that foods with a low nutrient value (grasses, mosses, lichens, plant debris, wood, and roots of various plants) prevent Macrolepidoptera species from spreading in the Subarctic region. In the Polar Urals, multiyear developmental cycles and wintering at the larval stage are related to feeding on these types of food.  相似文献   

4.
With regard to published data on the ecology of early peled larvae acclimated in lakes or reared under experimental or fish farm conditions, interannual variability of feeding and environmental conditions during the transition to exogenous feeding has been demonstrated for peled larvae in a control water body located in the floodplain of the main spawning tributary of the lower Ob River. The conditions that govern exogenous food consumption by early peled larvae and largely determine the fate of a given generation depend on both biotic (the concentration of food organisms) and abiotic factors (wind regime). The trophic optimum during the transition of larvae to exogenous feeding, which ensures the level of gut filling sufficient for their survival and growth in the control water body, is determined by a complex of natural events. The results of this study may be extrapolated to the entire native range of the Ob River peled population and used for planning the release of peled larvae into natural water bodies of Western Siberia to compensate for losses to their biological resources.  相似文献   

5.
Downstream migration (larval drift) of coregonids in the lower reaches of the Severnaya Sos??va River (the largest spawning tributary of the Lower Ob) has been analyzed from ecological aspects such as the long-term, seasonal, and daily dynamics and the spatial distribution, growth, and feeding of larvae in the current. Considerable changes in the abundance of coregonid generations have been revealed. It is shown that downstream larval migration over a long route has a number of features distinguishing it from that at spawning grounds. In particular, mass migration takes place after the ice drift, and its intensity is independent of changes in flow discharge. The drifting larvae display species-specific distribution in the current, and their density is the lowest in the surface water layer. In the course of migration, their linear body growth is accompanied by considerable depletion of endogenous food reserves and transition to active feeding.  相似文献   

6.
Dairy feeding systems in many semi-arid countries are based on imported concentrates and forages. This has economic and ecological implications given the increase in global feed prices and greenhouse gas (GHG) emissions from land use change. This paper aims to explore alternative dairy feeding systems under semi-arid conditions, using Jordan as an example. The feedings systems under investigation vary in their share of food industry by-products (replacing concentrates in the diet) and are compared against the current concentrate-based feeding systems. The systems are evaluated against three criteria: their nutritional value, their impact on the cost of milk production, and their GHG mitigation potential. Feed samples from eleven food industry by-products and ten conventional feeds were collected from food factories and from three typical dairy farms, representing the typical large-, medium- and small-scale farm types, respectively. Feed samples were analysed for their chemical composition and metabolisable energy contents. In addition, economic and production farm data were collected and entered into a model for GHGs calculation and economic evaluation. The results suggest that inclusion of locally available food industry by-products in the rations of milk cows in semi-arid production systems can be instrumental in reducing production costs and mitigating GHG emissions. Cost of milk production in the model farms can be lowered by up to 14 %; mitigation of CO2 eq. emission ranged between 70 and 290 g CO2 eq./kg milk. The degree to which these benefits can be reaped is positively related to the level of inclusion of by-product feeds in lactating cows’ diets.  相似文献   

7.
人口增多,耕地减少,部分地区供水不足,是我国人口与资源矛盾的基本格局。由于人口的压力,对资源实行超强度的利用,使较大范围的地区生态环境恶化,严重威胁农业生产,并成为许多地区多灾、低产、贫困的根本原因,较低的食物人均占有水平,将继续成为中国国民经济发展和人民生活水平提高的严重限制因素。增加食物,必须挖掘资源的潜力,开源与节流相结合,以内涵挖潜为主。首先是要立足现有的耕地,致力于提高单产;同时,合理开发水域、山地、草地等资源,广辟食物来源,提高非耕地资源的生产力,提高林牧渔业的发展水平。耕地应以深度开发为主,走资源节约型(节地、节水、节时、节能)的集约化道路。  相似文献   

8.
Abstract

Literature analysing reasons for Consumer Food Waste (CFW) revealed that it cannot be reduced to consumer behaviour alone. In fact, CFW should not be conceptualised as the problem but as a symptom of a food system that oversupplies and encourages consumerism. This research focuses on preventing CFW in the United Kingdom (UK), as a representative of a developed country, by improving the traditional food provisioning system to better integrate production and consumption. To achieve this, five stages are identified to design a sustainable product service system (PSS) capable of supporting consumers to better manage their food operations: (1) strategic analysis of current food provisioning system, (2) exploring system level innovations leading to minimisation of CFW, (3) refinement and selection of PSS, (4) designing the most promising PSS from an environmental, economic and social perspective, and (5) evaluating designed PSS. This paper considers the first of these stages, reviews reasons for and existing solutions to CFW, and provides a strategic analysis of the current food provisioning system to identify characteristics that could be exploited within a new PSS. Initial investigations reveal applicability of PSS concept to the food provisioning system and potential for reduction of CFW if core causes are addressed.  相似文献   

9.
The composition of pied flycatcher (Ficedula hypoleuca Pall.) nestling diet was studied in the zone of strong pollution with emissions from the Middle Ural Copper Smelter (Revda, Sverdlovsk oblast) and in the background area from 2005 to 2007. The results show that diversity of the diet decreases and prevalence in it of one insect taxon (Lepidoptera) increases near the source of emissions. The proportion of uncharacteristic food objects (orthopterans, herpetobiont invertebrates) and variation in the size of invertebrates brought by parents to their nestlings increase, which is explained by degradation of forest habitats in the polluted area. Pied flycatchers provide nestlings with sufficient quantities of food, but its quality in the polluted zone is lower than in the background area.  相似文献   

10.
食物波动与效率是食物安全的重要研究内容。1993~2003年江西省平均食物生产全要素相对生产率为0.974,其规模效益基本上呈现常数规模效益与规模效益递增交替波动现象。灰色关联分析表明,粮食产量、油料产量、肉类产量、糖料产量等与食物总量具有显著关联性,其灰色关联序为:粮食产量>油料产量>肉类产量>糖料产量>禽蛋产量>水果产量>牛奶产量,所以要保证食物总量安全,必须首先保障粮食、油料、肉类等的生产。  相似文献   

11.
In this paper we develop a novel, comprehensive method for estimating the global human carrying capacity in reference to food production factors and levels of food consumption. Other important interrelated dimensions of carrying capacity such as energy, non-renewable resources, and ecology are not considered here and offer opportunities for future work. Use of grain production (rain-fed/irrigated), animal product production (grazing/factory farm), diet pattern (grain/animal products), and a novel water accounting method (demand/supply) based on actual water consumption and not on withdrawal, help resolve uncertainties to find better estimates. Current Western European food consumption is used as a goal for the entire world. Then the carrying capacity lies in the range of 4.5–4.7 billion but requiring agricultural water use increase by 450–530% to 4725–5480 km3, the range based on different estimates of available water. The cost of trapping and conveying such water, will run 4.5–13.5 trillion over 50 years requiring an annual spending increase of 150–400%, straining the developing world where most of the population increase is expected. We reconfirm estimates in the literature using a dynamic model. ‘Corner scenarios’ with extreme optimistic assumptions were analyzed using the reasoning support software system GLOBESIGHT. With a hypothetical scenario with a mainly vegetarian diet (grazing only with 5% animal product), the carrying capacity can be as high as 14 billion. Ecological deterioration that surely accompanies such a population increase would negatively impact sustainable population. Using our approach the impact of ecological damage could be studied. Inter- and intra-regional inequities are other considerations that need to be studied.  相似文献   

12.
Focusing on recent documentaries about sustainable agriculture in the US—Food, Inc., The Garden, Fresh, and Farmageddon—this paper examines how pro-sustainable food arguments fail to merge environmentalism and environmental justice. By framing their approach to sustainable food production around the normative issue of “good food” for capitalist consumers, such documentaries ignore questions about community and cultural conceptions of farmers. In the process the films promote a problematic vision of the white family farm. As a consequence, these films limit a reimagining of alternative food systems, the roles for diverse actors within those systems, and possibilities for eaters beyond “voting with your fork.” Several exceptions, most notably The Garden, are used to suggest how cinema might radically re-envision participation in alternative forms of agriculture.  相似文献   

13.
Soil Erosion: A Food and Environmental Threat   总被引:14,自引:0,他引:14  
Soil erosion is one of the most serious environmental and public health problems facing human society. Humans obtain more than 99.7% of their food (calories) from the land and less than 0.3% from the oceans and other aquatic ecosystems. Each year about 10 million ha of cropland are lost due to soil erosion, thus reducing the cropland available for food production. The loss of cropland is a serious problem because the World Health Organization reports that more than 3.7 billion people are malnourished in the world. Overall soil is being lost from land areas 10 to 40 times faster than the rate of soil renewal imperiling future human food security and environmental quality.  相似文献   

14.
食品安全与农药残留一直是备受关注的焦点问题。基于此,本文应用山东省蔬菜出口产地安丘市392个农户的调查数据,对农户食品安全规制的认知及其农药使用行为的影响因素进行了分析。研究结果表明,农户的学历层次、农产品国内销售和出口日本的比例、农户对国内外农产品市场的评价及是否接受农药残留检测显著影响其对食品安全规制的认知;而农户的平均生产支出、是否接受农药残留检测、检测标准的严格程度及是否作生产记录影响其农药使用行为。此外,本文发现该制度的实施导致一些农户产生逆向选择,且农户的农药使用因种植结构而不同。针对当前农业生产的特点和食品安全现状,为了促进当地农业生产方式的转变和保护生态环境,政府应加强对农业主体的培训和技术指导,引导当地农户加强与产业组织的联系,有效开展农药残留检测、优化种植结构,提高农产品的质量和国际竞争力。  相似文献   

15.
Polychlorinated biphenyls (PCB) congeners were determined in water samples, sediments, and animal species in the frame of a survey of the River Arrone (Central Italy, near Rome) after a major contamination episode. Animal species were selected on the basis of their living and feeding habits and evaluated as candidate bioindicators of PCB pollution in this lotic ecosystem. Total PCB concentrations in water were found to be low (ng/L level), and in sediments, ranged from about 10 to 200 μg/kg dry weight, depending on the distance from the contamination source. PCB patterns in sediments showed a prevalence of higher chlorinated congeners over time. Concentrations in macroinvertebrates (Calopteryx splendens and Anax imperator) ranged from 60 to 400 μg/kg dry weight, showing significantly different species to species patterns. PCB concentrations were almost parallel in sediments for different sampling stations, while differences in patterns among species can be explained in terms of bioaccumulation/excretion mechanisms. Freshwater shrimps (Palaemonetes antennarius) were not found close to the contamination source, as a consequence of their extreme sensitivity to chemicals, and showed a peculiar pattern (almost exclusively determined by congeners 153, 138, and 180) probably originating from biodegradation mechanisms. Fish samples (Rutilus erythrophthalmus) showed the highest concentrations, as a combination of feeding habit, lipid content, and, probably, less effective biodegradation/excretion pathways. Congener patterns closely match those of Aroclor 1260, which originates from the contamination source. This study confirms that congener physical and chemical parameters, different degradation rates, feeding habits, and mobility of the analysed aquatic organisms, metabolism, and excretion mechanisms, are to be considered to explain the distinctive PCB patterns of different samples.  相似文献   

16.
基于粮食主产区农业发展及其结构调整中面临的问题分析,指出近5年来导致我国粮食产量持续下降的主要原因在于农业结构调整。大规模的“压粮扩经”趋势若不能有效控制,必将对国家粮食安全带来冲击。对2005-2010年我国粮食需求及粮食主产区占全国粮食产量比重进行测算.提出不同粮食自给率下国家粮食安全对粮食主产区粮食生产的目标要求。粮食主产区具有满足国家粮食安全产量需要的生产潜力。  相似文献   

17.
贸易中的虚拟水研究使人们认识到地区的水资源危机可以通过全球性的经济贸易来缓解。虚拟水的进出口是水资源的一个来源,通过贸易的形式、利用各种外部资源来缓解内部水资源的紧缺,最终解决水资源短缺和粮食安全问题,是社会实现水资源社会化管理、生态环境安全和社会经济可持续发展的战略保障。以浙江省为研究对象,首先利用各类农作物虚拟水含量标准,核算了1997~2006年10 a间浙江省粮食贸易的虚拟水含量。然后比较浙江省全年用水量和用水结构,计算得出粮食贸易产生的年净进口虚拟水量占浙江省年总用水量7.41%左右,占到年农业灌溉用水的1717%。研究结果表明,过去10 a浙江省粮食贸易的虚拟水是浙江省水资源的一个重要的补充。〖  相似文献   

18.
The most informative characteristics of the zooplankton-community response to the effect of industrial wastewater from mines have been determined using water bodies of the Kola Peninsula as an example. It has been demonstrated that qualitative and quantitative characteristics of zooplankton depend on the degree of industrial pollution of a water body and adequately reflect differences in the conditions of zooplankton growth between the whole water bodies and their individual parts. The role of zooplankton as an indicator has been assessed and the possibility of including it in the system of monitoring of water objects has been substantiated.  相似文献   

19.
水-粮食贸易:虚拟水研究进展   总被引:18,自引:0,他引:18  
虚拟水思想强调的是水资源贡献,量化计算是其深入研究的基本,而是否选择虚拟水作为战略政策,应该考虑由不同国家的资源贡献和生产技术决定的比较利益。社会调适能力要求社会针对资源的第一性缺乏做相应调适并谋求解决手段,以提高资源管理能力。为此,需要结合我国的水和粮食安全问题,提出用虚拟水贸易解决我国水资源和粮食问题,提高我国对水资源缺乏的调适能力。  相似文献   

20.
安徽省是重要的粮食产区,在保障我国粮食安全中发挥着重要作用,研究该省气候生产潜力的演变特征,面向粮食安全分析其气候承载力具有显著的现实意义。本文从粮食生产与光温水等气候因子的关系出发,采用逐级订正的方法计算了安徽省的气候生产潜力及其变化特征,并根据不同生活水平下的粮食需求指标,分析了安徽省的气候承载力和剩余空间。结果表明,安徽省气候生产潜力的地理分异特征显著,其中北部高于南部、平原高于山区,高值区主要集中在沿淮及淮北地区,与耕种条件配合较好,有利于生产潜力的发挥。1961~2013年全省气候生产潜力基本呈一致下降趋势,近50年平均减少了约10%。安徽省目前粮食消费水平和结构属温饱型向小康型过渡阶段,在充分发挥气候生产潜力的前提下,全省气候资源所能承载的粮食产量均显著超过不同生活水平下的总需求量。小康水平下,气候承载力的相对剩余率总体呈东北向西南递减的趋势,除部分城市地区和山区外,全省大部地区气候承载力的剩余空间仍较富裕,能够较好的保障粮食需求。总的来看,由于安徽省光温水以及耕地等条件配合较好,气候承载力较高;虽然受太阳辐射影响,近年来气候生产潜力下降,但在保障未来小康社会的粮食安全方面,安徽省仍具有较好的气候承载力,粮食生产还有较大的提升空间。  相似文献   

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