International trade in meat: the tip of the pork chop

This paper provides an original account of global land, water, and nitrogen use in support of industrialized livestock production and trade, with emphasis on two of the fastest-growing sectors, pork and poultry. Our analysis focuses on trade in feed and animal products, using a new model that calculates the amount of "virtual" nitrogen, water, and land used in production but not embedded in the product. We show how key meat-importing countries, such as Japan, benefit from "virtual" trade in land, water, and nitrogen, and how key meat-exporting countries, such as Brazil, provide these resources without accounting for their true environmental cost. Results show that Japan's pig and chicken meat imports embody the virtual equivalent of 50% of Japan's total arable land, and half of Japan's virtual nitrogen total is lost in the US. Trade links with China are responsible for 15% of the virtual nitrogen left behind in Brazil due to feed and meat exports, and 20% of Brazil's area is used to grow soybean exports. The complexity of trade in meat, feed, water, and nitrogen is illustrated by the dual roles of the US and The Netherlands as both importers and exporters of meat. Mitigation of environmental damage from industrialized livestock production and trade depends on a combination of direct-pricing strategies, regulatory approaches, and use of best management practices. Our analysis indicates that increased water- and nitrogen-use efficiency and land conservation resulting from these measures could significantly reduce resource costs.     

A method of approach to landscape stability. Part 1: Fundamentals and methodology

A four-stage method of providing conditions for improving the stability of a landscape sector is presented. In the first stage, structure and function of the landscape system is examined, predominantly based on the results of monitoring. In the second stage, a method is suggested for applying monitoring data to a dynamic structure with complex functions of the territory under examination. In the third stage, the territory is optimized as to the function of particular components within it. The optimization consists in controlling the dynamics of the flows of material, energy, and population within the sector. In the fourth stage, the holistic function of the landscape strip should be monitored with respect to representative key factors. The entire concept is based on assuming the existence of destabilizing processes leading to ecocritical situations and determining mitigating factors using heuristic methods of optimization.     

A method of approach to landscape stability. Part 2: Ecooptimization of experimental territorial landscape segment in Bohemian forest

The method of anthropoecological landscape stability (AELS) has been applied experimentally to a territorial unit, forming a closed watershed with more of less precisely defined material, energy, and population flows. This article presents data-driven results of monitoring and conclusions on optimizing features derived from two object-oriented expert systems—the FORELIS, giving heuristically optimal conditions for forest compositions on the site in the prevailing immission situation, and AGRILIS—the agricultural expert system having the scope of finding suitable forms of agriculture with respect to natural conditions and suitable actual production facilities. The results of the study fully confirmed the feasibility of applying expert systems to actual conditions, and no significant errors in the results of the expert systems compared to indications by monitoring have been disclosed.     

Umbilical and uterine flow velocity waveforms in pregnancies complicated by major fetal anomalies

A continuous wave Doppler unit was used to obtain umbilical and uterine artery flow velocity waveforms in pregnancies complicated by a major fetal abnormality. A total of 139 examinations were performed on 32 women between 26 to 41 weeks' gestation, and the records were reviewed to determine the changes associated with fetal malformation. The systolic/diastolic (A/B) ratio was used as an index of blood flow resistance in the umbilical artery and the systolic minus diastolic divided by systolic (A–B)/A for the branches of the uterine artery. Seventeen out of 32 patients showed high systolic/diastolic ratio in waveforms taken from the umbilical artery. In 30 out of 32 patients the uterine artery waveform was normal (in two patients the results were equivocal). It appears that a fetal mechanism may determine the changes in the umbilical placental circulation resulting in an umbilical artery pattern of high flow resistance in more than half of the patients with congenital anomalies.     

Nitrogen and food production: proteins for human diets

Nitrogen was the most commonly yield-limiting nutrient in all pre-industrial agricultures. Only the Haber-Bosch synthesis of ammonia broke this barrier. The rising dependence on nitrogenous fertilizers, which represents the largest human interference in the biospheric N cycle, has two different roles. In affluent nations it helps to produce excess of food in general, and of animal foods in particular, and it boosts agricultural exports. But for at least a third of humanity in the world's most populous countries the use of N fertilizers makes the difference between malnutrition and adequate diet. Our understanding of human N (protein) needs has undergone many revisions and although some uncertainties still remain it is clear that average protein intakes are excessive in rich countries and inadequate for hundreds of millions of people in Asia, Africa, and Latin America. More dietary protein will be needed to eliminate these disparities but the future global use of N fertilizers can be moderated not just by better agronomic practices but also by higher feeding efficiencies and by gradual changes of prevailing diets. As a result, it could be possible to supply adequate nutrition to the world's growing population without any massive increases of N inputs.     

Land use and management in the People's Republic of China

Widespread disregard for essential principles of sound environmental management and protection during the three decades of Communist rule prior to 1980 have exacerbated traditional shortages of good arable land and productive forest cover in the People's Republic of China. The government's policies have also drastically reduced valuable freshwater surfaces, caused extensive grassland deterioration and soil erosion, and brought about many local and regional climatic changes. However, new policies put into effect recently are attempting to reverse these trends with a sound ecosystemic approach to land management.     

Energy and Air Pollution: Usa 1970-2020

The power industry in the United States has entered a transitory period of major changes. Until a more definitive pattern emerges the image of the future of the industry and of the levels of air pollution generated by the industry will remain far from clear. Computer simulations based on the best currently available consensus can reveal patterns of possible future alternatives. Here three scenarios, discussed in detail, demonstrate that the actual course of the industry will depend to a high degree on our choices. Self sufficiency, a highly desirable goal for U. S. energy can be achieved sometime during the 1980’s, but not without massive increases in the use of coal and nuclear power. Absolute shares of these two principal sources will be determined by the relative success of emerging technologies.     

氮和食物生产:人类饮食中的蛋白质

在工业化前的各类农业中,氮是最普通的作物产量限制性营养元素,但氨的Haber-Bosch合成法最终突破了这种限制.人类对氮肥不断增强的依赖性是对生物圈氮循环最大程度的干扰,其作用表现在两个方面:在富裕的国家,通常它有助于生产出过剩的食物,特别是动物性食物,并且增加农产品出口量;但是,在人口最稠密的国家,氮肥的使用使至少1/3的人的饮食介于营养失调和营养丰富之间.我们对人类氮(蛋白质)需求的理解经历了许多次修正,尽管仍有一些不确定之处,但是有一点是清楚的,在富有的国家,蛋白质的平均摄入量过多,而对于数亿的亚洲、非洲和拉丁美洲人来说,摄入量又不足.将需要更多的饮食蛋白质以消除这些差别.通过合理的耕作方式,以及通过更高效率的饲料转化和主要饮食结构的逐渐改变,未来全球性氮肥使用量可以减少.最终,在不输入大量氯的情况下,使日益增长的世界人口获得丰富的营养物质将成为可能.