我国人口资源与食物问题

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。     

Simulation of cladoceran survival strategy under conditions of food depletion

Competition between several cladoceran species has been studied with the use of simulation. The results have demonstrated that, in most cases, one or two species survive. Under conditions of the minimum food supply, the most competitive species have the selective advantage. With an increase in food supply, the survival of low-competitive species was observed more often. The mean body size of surviving species increases with an increase in food reproduction.     

Will Limits of the Earth's Resources Control Human Numbers?

The current world population is 6 billion people. Even if we adopted a worldwide policy resulting in only 2.1 children born per couple, more than 60 years would pass before the world population stabilized at approximately 12 billion. The reason stabilization would take more than 60 years is the population momentum – the young age distribution – of the world population. Natural resources are already severely limited, and there is emerging evidence that natural forces already starting to control human population numbers through malnutrition and other severe diseases. At present, more than 3 billion people worldwide are malnourished; grain production per capita has been declining since 1983; irrigation per capita has declined 12% during the past decade; cropland per capita has declined 20% during the past decade; fish production per capita has declined 7% during the past decade; per capita fertilizer supplies essential for food production have declined 23% during the past decade; loss of food to pests has not decreased below 50% since 1990; and pollution of water, air, and land has increased, resulting in a rapid increase in the number of humans suffering from serious, pollution-related diseases. Clearly, human numbers cannot continue to increase.     

人口与可持续发展

有限的资源不能支撑无限增加的人口，面对高速增长的人口，人们产生了种种不同的认识。本文分析了人口增长与食物供给，人口增长与生态环境和经济发展的矛盾；阐述了最大人口容量及经济最优人口计算需要考虑的因素和基本；提出我国必须坚持严格控制人口增长的政策，这是可持续发展的需要。     

Latitudinal Gradients of Trophics in Ural Macrolepidoptera: The Role of Food Quality

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.     

芜湖市土地资源人口承载力与可持续发展研究

作为人类赖以生存和发展物质基础的土地资源有限性与人口的增长加剧了人地间的矛盾 ,土地资源人口承载力问题日益引起社会关注。在总结芜湖市土地资源利用现状、特点和当前人口食物消费水平的基础上分析了土地现实生产能力 ,同时为预测芜湖市 2 0 0 0、2 0 0 5、2 0 10年人口数量、复种指数、耕地面积及粮食单产发展趋势而分别建立了一元线性回归模型与灰色系统 GM(1,1)模型 ,通过取其平均值以提高其精度 ;并结合温饱型、宽裕型、小康型与富裕型四种消费水平分别探讨了预测期内芜湖市土地资源人口承载力状况 ,最后从耕地总量动态平衡、提高粮食单产与质量及控制人口增长等方面提出了可持续发展对策 ,为芜湖市建立稳定、协调、持续发展的人地关系提供科学的理论依据     

大别山五针松种群结构及动态研究

大别山五针松(Pinus dabeshanensis)是大别山区特有种,最大种群分布于安徽省岳西县大王沟。采用空间序列代替时间的方法分析种群结构,编制种群特定时间生命表,绘制死亡率曲线和消失率曲线,并用4个生存函数进行种群的生存分析;同时结合谱分析方法,分析了大别山五针松种群数量的动态变化。结果表明:大别山五针松种群数量少,结构存在波动性。幼苗阶段个体较丰富,幼树阶段个体较少,种群趋于衰退。种群死亡率和消失率曲线变化趋势基本一致,在第5龄级出现峰值。4个生存函数曲线表明,大别山五针松具有前期快速减少、中期稳定和后期衰退的特点。谱分析显示,大别山五针松种群动态除受基波影响外,还具有明显的小周期波动,谐波A3和A4处的周期波动与个体生长有关。     

全面放开二孩政策背景下人口增长对资源环境的影响和需求分析

2015年底,我国全面放开了二孩政策,势必对我国的人口总量和增长态势产生深刻影响,进而影响我国的资源需求和环境压力。在采用队列元素法预测全面放开二孩后我国总人口及各省(市、自治区)人口的基础上,运用城乡人口比增长法预测未来城镇化水平,本文依据这两种预测结果系统探讨人口政策变动对我国资源消费、环境污染的定量预测和具体影响。假定未来的人均资源环境消耗量保持现状不变,按照预测的未来人口总量和增量,得出人口增长对我国资源环境的需求变动。通过计算新增的资源环境需求量,对比需求总量与我国的资源环境供给能力,进一步分析人口增长对资源环境各方面的压力大小。研究发现:全面放开二孩政策后,我国的粮食、生活用能源、生活用水、城乡建设用地的需求量和生活污染物排放量均逐年递增,但变化速率有所差异。为满足未来人口增长所产生的需求,粮食和能源的自给率明显降低,未来将需要更多地依赖进口。全国的供水能力和保障水平急需提高,其中北京、河南、江苏、青海、四川的现状供水能力与未来生活用水需求差距较大。各省建设用地需求差异明显,吉林、湖北、山东、四川、江苏、湖南、新疆、广东、黑龙江、贵州等省市的城市建设用地新增需求量将快速释放,但已有的建设用地储备无法满足预测需求。生活污染物的治理压力加大,环境保护与治理能力应该继续加强。     

人口增长、收入水平与城市环境

伴随着我国城镇化进程的不断加快,城市环境污染问题备受关注。本文以城镇居民生活垃圾污染行为为起点,通过比较居民与政府目标函数,首先从理论上做出判断,城镇人口数量增加以及居民生活质量提高均会导致城市生活垃圾数量增长,从而对城市环境产生影响。随后,进一步采取Panel data的分析方法,以我国2004-2008年省级面板数据为样本,从城市生活垃圾污染的角度对我国城镇人口增长、居民收入水平与城市环境间的关系进行计量检验。结果显示:我国城市生活垃圾产生数量分别与城镇人口增长、居民收入水平间存在着长期正向协整关系,即在我国城镇化水平和居民生活质量不断提升的背景下,城市生活垃圾数量的增长以及对城市环境的污染存在着内在必然性;另外,我国城市生活垃圾数量的自发增长对平均增长的偏离逐年下降,可见,存在政策、制度、行为等外生因素抑制我国城市生活垃圾数量的增长。最后,文章从生活垃圾控制和处理的角度,就改善我国城市环境和促进城市环境可持续发展提出了简要的政策建议。     

中国仍应严格控制人口增长——论人口增长与经济增长的关系

在中国人均资源贫乏、人口对生态系统压力增大、经济落后、有效需求不足以及失业严重的情况下 ,人口过快增长既不能促进资本增长 ,也不能促进技术进步 ,它只能会减缓人均收入的提高。因此 ,为了促进人均收入的提高 ,必须尽可能降低人口增长速度     

Appropriateness of needles of different conifer species for the feeding and growth of larvae from two populations of the Siberian moth

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.     

食物安全:基于食品系统理论的探讨

在经济发展、消费升级、资源短缺和环境问题凸显的新的外部环境背景下,本文引入了国外新兴的食品系统理论,探讨并提出了可持续的食物安全保障的新观念.食物安全始终是中国经济发展、社会稳定和国家自立的基础.国内多数学者仍然用30年前食物匮乏时期的思路来研究现代的食物安全问题,其结果导致研究结论与现实情况不符.如何在节约资源、减少浪费的同时又能够满足人们不断升级的食物消费需求,是对未来食物安全保障的新要求.本文首先分析了我国食物安全研究的现状,指出了不足和问题,然后引入国外新兴的食品系统理论,在探讨其概念内涵的基础上,剖析了食品系统与食物安全的关系,影响食物安全的因素和研究视角,并进一步提炼出基于食品系统理论的新的食物安全保障观念,为我国研究食物安全提供借鉴.     

经济发展中人口城市化与经济增长相关分析比较研究

本文利用OECD国家和世界其他主要国家的人口城市化与经济增长的数据，对人口城市化与经济增长进行了相关分析，以揭示人口城市化与经济增长的关系模式。判断得到我国人口城市化仍处于低增长水平的线性阶段，城市化水平，大大滞后于经济发展水平；大大落后于发达国家同等经济水平时的城市化水平，经济发展与人口城市化的相互促进作用还没有得到充分发挥。为此，文章提出了要加快我国城市化发展，超前于经济的增长是一个理性选择。     

GIS支持的县域人口迁移空间模型研究--以浙江省临安市为例

人口迁移引起人口的数量、质量、结构等要素的空间分布发生变化,是人口地理学研究的重要内容之一。目前对人口迁移模型的研究大多是以行政区划作为计算单元,难以反映小尺度下行政区内部的人口迁移态势。在GIS的支持下,提出构建县域人口迁移引力模型,选择县域内独立的居民区片为计算单元来评价乡镇的人口吸引潜力和人口最大可能迁移目的地分布。以浙江省临安市为实验区,实现模型的运算,检验结果表明模型能较好地反映各乡镇对人口的实际吸引力,为研究区制定人口、经济等政策和辅助规划提供了科学合理的依据。     

Optimum Supportable Global Population: Water Accounting and Dietary Considerations

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.     

Confronting a Surfeit of People: Reducing Global Human Numbers to Sustainable Levels An Essay on Population Two Centuries after Malthus

It has become increasingly evident over the past several decades that there is a growing tension between two seemingly irreconcilable trends: (1) moderate to conservative demographic projections that world population size could easily reach 9 billion (or more) by the mid-to-late twenty-first century; and (2) prudent and increasingly reliable scientific estimates suggesting that the Earth's long-term sustainable carrying capacity (at an 'adequate to comfortable' standard of living) may not be much greater than 2–3 billion. I therefore argue that it is now time – indeed, past time – to develop and implement a set of well-conceived, clearly articulated, broadly equitable and internationally coordinated sociopolitical initiatives that go beyond merely slowing the growth – or even the stabilization – of global human numbers. After summarizing a number of 'inescapable realities' that the human species must soon confront, and notwithstanding the considerable difficulties involved in establishing rational and defensible global population optimums, I conclude with several suggestions relevant to the next logical step: how best to bring about a very significant reduction in global population size over the next two to three centuries. To the extent that there is still time to choose whether this dramatic decrease will be under conscious control or essentially chaotic, these proposals are cautiously optimistic.     

湖北省榉树自然种群分布研究

对湖北省天然榉树的自然种群分布现状、种群特征及种群分布格局进行了研究。结果表明：湖北榉树资源主要分布在海拔500~1 000 m地带,不同程度地分割包围在谷底和山腰,地理分布点呈收缩集群分布,种群规模较小;采用方差/均值法对榉树地理分布格局类型进行分析,其值=1.66>1,表明其分布点的地理分布趋于集群分布。湖北榉树种群星散间隔的地理分布形式,使地理分布点间产生空间间隔,成为相互间基因交错的障碍,而较小的种群规模,增加了遗传漂变的机率,导致遗传上的不稳定性增加,影响种群的生存能力,这些是导致物种趋向濒危的重要原因。湖北榉树种群这种分布现状产生的原因,一方面是物种自身的生物学特性及对生境的特定要求所致,另一方面是由于人类对榉树资源的过度开发利用以及人类经济活动导致的生境片段化。应借助于人为帮助,改善生态环境,扩大其种群规模,促进不同种群之间的基因交流,以利保护。     

Spatial population structure in forest voles of the genus <Emphasis Type="Italic">Clethrionomys</Emphasis> in the southern taiga of the Middle Irtysh region

A comparative analysis of spatial population structure in the northern red-backed vole (Clethrionomys rutilus Pall.) and large-toothed red-backed vole (Cl. rufocanus Sund.) has been performed in the middle taiga zone of the Middle Irtysh region (Omsk oblast). Populations of these species are represented by sets of territorial groups whose numbers and spatial distribution change from year to year depending on the ratio of these species in a biotope and their population density. There is no significant interspecific competition between cohabitant Cl. rutilus and Cl. rufocanus. In particular, this follows from the fact that the population density and distribution pattern of one species are independent of those of the other species. It has been found that the size of home ranges in Cl. rutilus inversely depends on its population density, with that in Cl. rufocanus remaining approximately the same at different population densities, and that the structure of the resident part of the population in both species changes during the season, as voles from neighboring habitats or dispersing voles settle in the study area.     

New Aspect in Understanding the Biocenotic Role of Domestic Ungulates in the Life of Wolf (<Emphasis Type="Italic">Canis lupus</Emphasis> L.)

The dynamics of wolf attacks on domestic ungulates at the levels of population group (the region of Central Forest Nature Reserve) and population (Tver oblast) have been analyzed over the period of 1971 to 2015. It has been found that the frequency of attacks increases during the phase of predator population growth under the effect of qualitative changes within the population. An increase in the frequency of attacks and the number of sheep and calves killed per attack also takes place in the summer–autumn period, as a consequence of training wolf cubs in methods of killing prey. Therefore, domestic animals are not only a source of food for the wolf but also an object for training the young.     

Changes in the dry tropical forests in Central India with human use

Understanding changes in forest composition and structure is important to help formulate effective policies that promote future ability of forests to provide local livelihood needs, habitat and ecosystem services. This is particularly important in dry tropical forests that are ecologically different from other forests and are heavily used by local, forest-dependent residents. In this study, we identify biophysical, demographic and use factors associated with differences in species diversity, vegetation structure (abundance at different size classes), biomass and relative abundance of species across the Kanha–Pench landscape in Central India. We sampled vegetation in twenty transects across different human and livestock population densities and frequencies of use. We found that biomass, species diversity and vegetation (abundance at different size classes) are negatively associated with increasing population density, and species composition at different size classes is significantly different at higher frequencies of use at low population densities. Lack of difference in species composition at high population densities may be due to colonization and growth of individuals at some of these sites due to creation of new ecological niches and gaps at high human use. Relative abundance of species at different size classes also varies with frequency of use and population density. Results suggest that human use is altering relative abundance of species, which may change long-term forest composition and thus alter biomass and vegetation structure of the forest. We conclude that human use is an agent in altering long-term composition that can alter availability of tree species for local use and other ecosystem services.