General Trends of Technological Changes in Agriculture

In this article we show that technological development in agriculture exhibits general trends when assessed on a large scale. These trends are generated by changes in the larger socioeconomic context in which the farming system operates. We characterize agricultural performance by land and farm labor productivity and the pattern of use of technological inputs. By means of a cross-sectional analysis of agricultural performance of 20 countries (at the national level), we show that increases in demographic pressure and socioeconomic pressure (increases in average income and labor productivity) in society are the main driving forces of technological development in agriculture. Further, it is shown that the ecological impact of farming (environmental loading) is linked to the particular combination of land productivity and labor productivity at which the agricultural sector operates (through the particular mix and the level of inputs used in agricultural production). Briefly we discuss the role of international trade in agricultural policies and performance. Special attention is given to the situation of Chinese agriculture.     

Does directed technological change get greener: Empirical evidence from Shanghai's industrial green development transformation

The degree of technological change biased to the environmental factor is crucial to industrial sustainable development. Using the stochastic frontier analysis method based on the translog production function and the panel data of 32 industrial sub-sectors in Shanghai over 1994–2011, this paper combines the evolution dynamic of the frontier technological structure with the evolution dynamic of technological change direction to estimate the output elasticities of production factors and the growth rate of green total factor productivity. Also, we investigate and compare the degrees of technological change biased to four production factors, i.e., capital, labor, energy, and carbon emissions. The results show that the industrial green total factor productivity in Shanghai presents an overall upward trend and mainly depends on the technical efficiency change. The improvements of labor productivity, R&D intensity, and energy efficiency can effectively enhance the green technical efficiency, while capital deepening has a mitigation effect on the green technical efficiency. The technological change of Shanghai's industrial production biases to energy use and capital saving, causing a high energy demand of industrial development. Under the dual impacts of economic development and energy-saving and emission-reduction policies, the degree of technological change biased to the environmental factor (carbon emissions) displays strong and weak alternations, indicating that the green bias of industrial technological change in Shanghai is not stable and that the green transformation of industrial development model needs to be further advanced.     

Caloric requirements of human populations: A model

Currently available models used for predicting human caloric requirements do not reflect the great variability in activity patterns observed among populations, and are insensitive to important anthropometric, demographic, and environmental variables. They are thus inadequate for application to many populations and problems of anthropological interest. We present a model for determining caloric requirements which more accurately accommodates the effects of variation in activity and in anthropometries on individual needs, and which predicts population requirements based on individual needs and demographic parameters. The model is tested on four populations (the Andean community of Nuñoa, Peru, the Dobe !Kung of Botswana, and two New Guinean villages) and is found to provide consistently better estimates of caloric requirements than are generated by the Food and Agriculture/World Health Organization's model. This model should be useful to anthropologists and human ecologists concerned with problems involving human energy consumption, such as the efficiency of subsistence strategies, optimum family composition, or certain consequences of increased labor migration or technological change.This research was supported by a grant from the Research Foundation of the State University of New York. Funds for computer time and materials were provided by the State University of New York at Binghamton and The Pennsylvania State University.     

Effect of density on larval development and female productivity ofTisbe holothuriae (Copepoda,Harpacticoida) under laboratory conditions

The harpacticoid copepodTisbe holothuriae has been cultivated in the Helgoland laboratory for more than 20 years. The effects of density on the larval development and the female productivity were studied by comparing two culture systems: (1) enclosed system, and (2) running-water system. In both systems, a nutritious mixed diet ofDunaliella tertiolecta, Skeletonema costatum, and granulatedMytilus edulis was offered. Larval mortality, larval development and female productivity are found to be significantly dependent on both the population density and specificity of the culture system. Increasing density causes higher larval mortality, longer larval development time, and a reduction in female productivity. In comparison with the enclosed system, the running-water system shows decisive advantages: larval mortality is about 20% lower, the rate of larval development is about two days shorter, and there is a very high rate of nauplii production. The sex ratio exhibits high variations, but in general, there is no clear relationship between sex ratio and population density. Nevertheless, when reared in the running-water system, a relatively high percentage of females (>45%) was found at lower densities.     

Methodological and Psychological Questions Concerning Dialogue Systems

Let me begin with a few principles familiar to us all. The present situation of society is marked by need for full and intensive utilization of all resources. The most valuable resource is human beings. The demand "from each according to his needs" is common to both today's socialist society and the communist society of the future. Hence, the all-round development and utilization of the capacities of each member of society are becoming increasingly important. Maximal growth in the productivity of labor states the same problem in a different way.     

Environmental and Socioeconomic Constraints to the Development of Freshwater Fish Aquaculture in China

In this article, we provide an overview, on freshwater fish aquaculture in P.R. China, with special emphasis on pond fish culture. We describe the history, ecology (trophic structure and species reared), and technological aspects (including inputs/outputs, yields, labor productivity, and fossil energy use) of freshwater fish production and analyze its role in relation to the socioeconomic context. We discuss the prospects for intensification of production. In China, freshwater fish aquaculture has always been closely linked to cultivation of crops and animal husbandry, that is, feed inputs are in the form of agricultural wastes. The close integration with the farming system at large results in an efficient use of nutrients, low environmental loading, and little dependence on fossil energy inputs. About 7 to 9 different fish species, mainly herbivores, are kept in the same pond and efforts are made to maintain as much as possible the natural mechanisms of matter regulation and energy flows within the pond ecosystem. However, ecological compatibility is paid for by relatively low productivity, both per hectare of waterbody and per hour of labor input. If the throughput of freshwater fish production per unit of area and labor are to be dramatically increased, the equilibrium of the traditional integrated system will be difficult to maintain.     

中国四川旱坡地植物篱农作系统能流特征

关于农业生态系统能流特征的研究很多,但关于植物篱农作系统能流特征的研究很少。在四川盆地雨养丘陵农区,2/3的耕地土壤侵蚀严重,为了控制土壤侵蚀和提高耕地生产力,该区域大量栽种了植物篱。该研究通过了解作物与植物篱之间的能流交付作用,通过系统能量投入水平提高与结构优化,建立环境友好的农作系统,最终实现坡地农业的可持续。通过两年田间小区试验,详细记录所有劳力投入、化肥投入、农药投入、农事管理活动以及落叶的数量并折算为标准能量单位。作物收获后所有生物产量的能量根据其各部分的转换值折算为标准能量。系统能流特征及效率通过统计分析完成。通过研究主要获得了以下3个结论:1)“作物-植物篱”系统产出能和输入能的数量和结构变化主要受植物篱子系统类型的影响。与大面积旱坡地传统农作物生产系统比较,植物篱农作系统能有效提高系统光能利用率、人工输入能效率,耕地单位面积总产出能也会增加,坡度越大,相对增幅亦越大;由于能极显著减少无机能施入量,这有利于降低化肥农药使用量,减少对环境的污染和破坏。2)“作物-果树类植物篱”系统输入能总量和有机能输入量大幅度增加,因此有利于优化输入能结构,促进坡地生态系统良性循环和集约高效农业发展。3)“作物-草本植物篱”系统人工辅助能的输入量大幅度下降,由于它所需投入能少,有机能耗和无机能耗均低,人工输入能效率很高而生物产量也较高,并且它们提高了与其间作的其它作物的能量产投比,因此提升了整个系统能量产投比率;由于保水固土的生态功能显著,使它能在四川广大山地、丘陵区退耕还林还草工程中发挥重要作用。     

The role of biomass in shifting cultivation

Shifting cultivation has traditionally been characterized as a highly productive system in terms of the ratio of energy outputs to inputs. This characterization, however, does not take into account the energy contribution of the natural vegetation cleared in preparing the field for cultivation. As a result, the central feature of shifting cultivation, the exploitation of the natural vegetationsoil complex as a substitute for human labor, has been ignored. The omission of the biomass contribution can be attributed to both a focus on the practices involved rather than the underlying strategy of the shifting cultivator, and an excessive preoccupation with the renewability of the energy sources involved in different agricultural systems. A definition of shifting cultivation is proposed that focuses attention on the relationship between the natural vegetationsoil complex and the shifting cultivator. Two methods of including the energy contribution of forest biomass in calculating the productivity of shifting cultivation systems are compared. When the biomass contribution is included, shifting cultivation appears to be an extremely unproductive system of agriculture.I would like to thank Bill Denevan, Chris Uhl, Christine Padoch, Tom Klak, Bob Buschbacher, and Mimi Kranichfeld for their comments on earlier versions of this paper.     

Subsistence and the Evolution of Religion

We present a cross-cultural analysis showing that the presence of an active or moral High God in societies varies generally along a continuum from lesser to greater technological complexity and subsistence productivity. Foragers are least likely to have High Gods. Horticulturalists and agriculturalists are more likely. Pastoralists are most likely, though they are less easily positioned along the productivity continuum. We suggest that belief in moral High Gods was fostered by emerging leaders in societies dependent on resources that were difficult to manage and defend without group cooperation. These leaders used the concept of a supernatural moral enforcer to manipulate others into cooperating, which resulted in greater productivity. Reproductive success would accrue most to such leaders, but the average reproductive success of all individuals in the society would also increase with greater productivity. Supernatural enforcement of moral codes maintained social cohesion and allowed for further population growth, giving one society an advantage in competition with others.     

基于MSIASM方法的沈阳城市代谢研究

本文采用社会代谢多尺度综合分析方法分析沈阳经济的演化过程。研究表明,1978～2003年,沈阳投入在第一、二产业的人类活动时间(HA值)所占比重有所下降;而第三产业的比重有增加趋势,但不明显;同时投入在家政部门的人类活动量(包括所有非经济活动)逐年下降;1978～1995年每个工作时间负担的非工作时间数量越来越小,1995～2003年每个工作时间负担的非工作时间数量越来越大,这与沈阳市的经济发展规律一致;沈阳社会/劳动生产率显著增加,社会经济生产率、社会劳动生产率、农业部门劳动生产率、生产部门劳动生产率,以及服务与管理部门的劳动生产率增长了20～30倍,说明沈阳的社会经济发展主要靠工业的拉动力。     

Scenario Analysis and Path Selection of Low-Carbon Transformation in China Based on a Modified IPAT Model

This paper presents a forecast and analysis of population, economic development, energy consumption and CO₂ emissions variation in China in the short- and long-term steps before 2020 with 2007 as the base year. The widely applied IPAT model, which is the basis for calculations, projections, and scenarios of greenhouse gases (GHGs) reformulated as the Kaya equation, is extended to analyze and predict the relations between human activities and the environment. Four scenarios of CO₂ emissions are used including business as usual (BAU), energy efficiency improvement scenario (EEI), low carbon scenario (LC) and enhanced low carbon scenario (ELC). The results show that carbon intensity will be reduced by 40–45% as scheduled and economic growth rate will be 6% in China under LC scenario by 2020. The LC scenario, as the most appropriate and the most feasible scheme for China’s low-carbon development in the future, can maximize the harmonious development of economy, society, energy and environmental systems. Assuming China''s development follows the LC scenario, the paper further gives four paths of low-carbon transformation in China: technological innovation, industrial structure optimization, energy structure optimization and policy guidance.     

Social structure and energy efficiency: A preliminary cross-national analysis

This study questions the assumption that there is an immutably positive relationship between per capita GNP and per capita energy consumption among human societies. A ratio of per capita GNP to per capita energy consumption ($U.S./kg coal equivalent) is proposed as a measure of energy efficiency for a cross-national analysis of 118 world nation-states and a subset of 25 developed market economies. This ratio is found to vary considerably, between 0.19 and 9.80. A review of literature suggests possible relationships among several sociodemographic characteristics of nations and levels of efficiency with which energy is converted into goods and services. Among the total sample, level of production (measured in terms of per capita GNP) bears a substantial inverse association with energy efficiency. When per capita GNP is held constant, agricultural share of gross domestic product and percentage of labor force in agriculture continue to be positively associated with energy efficiency among the total sample. Variables measuring defense expenditure, urbanization, and population density exhibit somewhat smaller multivariate relationships with energy efficiency when per capita GNP is controlled, i.e., these variables have significant multivariate parameters, but are less closely related to energy efficiency than level of production and agricultural composition of the economy and labor force. Agricultural composition of the economy and labor force is the major predictor of energy efficiency among the subset of 25 developed market economies. The results suggest that among the developed industrial societies level of production is less important than the composition of production activities in determining aggregate energy efficiency.This paper was originally presented at the annual meeting of the North Central Sociological Association, Pittsburgh, Pennsylvania, May 1977. This research was supported by funds from the Michigan Agricultural Experiment Station, the Ohio Agricultural Research and Development Center, and the National Research Council, National Academy of Sciences.     

Ecological engineering: A field whose time has come

Ecological engineering is defined as “the design of sustainable ecosystems that integrate human society with its natural environment for the benefit of both.” It involves the restoration of ecosystems that have been substantially disturbed by human activities such as environmental pollution or land disturbance; and the development of new sustainable ecosystems that have both human and ecological value. While there was some early discussion of ecological engineering in the 1960s, its development was spawned later by several factors, including loss of confidence in the view that all pollution problems can be solved through technological means and the realization that with technological means, pollutants are just being moved from one form to another. Conventional approaches require massive amounts of resources to solve these problems, and that in turn perpetuates carbon and nitrogen cycle problems, for example. The development of ecological engineering was given strong impetus in the last decade with a textbook, the journal Ecological Engineering and two professional ecological engineering societies. Five principles about ecological engineering are: (1) It is based on the self-designing capacity of ecosystems; (2) It can be the acid test of ecological theories; (3) It relies on system approaches; (4) It conserves non-renewable energy sources; and (5) It supports biological conservation. Ecology as a science is not routinely integrated into engineering curricula, even in environmental engineering programs, while shortcoming, ecologists, environmental scientists, and managers miss important training in their profession—problem solving. These two problems could be solved in the integrated field of ecological engineering.     

Socio-Economic Instability and the Scaling of Energy Use with Population Size

The size of the human population is relevant to the development of a sustainable world, yet the forces setting growth or declines in the human population are poorly understood. Generally, population growth rates depend on whether new individuals compete for the same energy (leading to Malthusian or density-dependent growth) or help to generate new energy (leading to exponential and super-exponential growth). It has been hypothesized that exponential and super-exponential growth in humans has resulted from carrying capacity, which is in part determined by energy availability, keeping pace with or exceeding the rate of population growth. We evaluated the relationship between energy use and population size for countries with long records of both and the world as a whole to assess whether energy yields are consistent with the idea of an increasing carrying capacity. We find that on average energy use has indeed kept pace with population size over long time periods. We also show, however, that the energy-population scaling exponent plummets during, and its temporal variability increases preceding, periods of social, political, technological, and environmental change. We suggest that efforts to increase the reliability of future energy yields may be essential for stabilizing both population growth and the global socio-economic system.     

Population,agriculture, and famine: Iceland, 1784–1785

Studies of past famines are useful as portrayals of a society under stress and valuable as testing grounds for ideas on the causes and consequences of famine. Older historical sources may lack some of the richness and detail available to students of modern famines, but history offers hindsight and valuable opportunities to integrate famine studies with long-term views of a society and its ecology. This paper takes a different tack from many economic histories of past famines, especially those that rely heavily on economic measures of ecological sufficiency, such as the prices of wheat, labor, and land. It describes the effects of the disastrous 1783 eruption of Iceland's Lakagigar (Laki craters) on a largely subsistent population for whom relief measures were belated and few. At the time of the disaster the entire population lived in households whose main livelihood consisted of farming or fishing. Both these activities were acutely disrupted by the eruption. In this paper, the course of the famine and its effects on population will be analyzed and reviewed in the light of long-term trends in Icelandic population and food production.     

Farming,fishing, and fire in the history of the upper Río Negro region of Venezuela

Studies of Río Negro subsistence farming and fishing activities are used to estimate the human carrying capacity for the region and the likely pattern of human land-use during prehistory. Ceramic evidence suggests human presence in the region more than 3000 years ago. Traditional farming is labor intensive and relatively unproductive. Nevertheless, farmers achieve an energy return of 15.21, and produce 2600 kcal per work hour. Fish are the major protein source, but fish catch per unit of effort and fish yield per hectare of floodplain are very low; fishermen are probably exploiting local fish resources very close to their limit. The low human population density would suggest that the Río Negro forest has been relatively undisturbed. Nevertheless, charcoal is widespread and abundant in forest soils. This charcoal is probably from anthropogenic or natural wildfires. These results suggest a much more complex history for Amazonia than previously thought.K. Clark is a free-lance biologist residing in Lima, Peru     

The relationships between net primary productivity, human population density and species conservation

Aim In this study, I determine the relationships between net primary productivity (NPP), human population density, species richness and land use. I also examine the implications of human settlement patterns for species conservation. Location Australia. Methods I document the associations between NPP, human population density and the species richness of birds, butterflies and mammals using correlations and spatial regressions. I also assess changes in land‐use with NPP and population density, focussing particularly on protected areas. An initial exploration into the implications of the NPP‐population density relationship for regional conservation strategies is provided. Results Human population density increases with NPP suggesting that available energy may be a key driving force of human settlement patterns. The species richness of each taxonomic group and geographically restricted species also increases with NPP leading to substantial overlap between species diversity and populated regions. The percentage of land designated as minimal use decreases considerably with increasing human population density and NPP, while intensive agriculture is confined entirely to areas of high NPP. There are strong negative relationships between the size of Australia's National Parks and human population density and NPP. Small parks are often surrounded by relatively dense settlements, but have high average NPP, while large parks are mostly isolated and characterized by low productivity. There are no areas in the highest quartile of NPP that also occur in the most sparsely populated regions, presenting challenges for conservation strategies wanting to protect productive areas under the least threat of human development. Main conclusions Human population density and species richness respond similarly to variation in NPP, leading to spatial congruence between human settlements and productive, species rich regions. Planning strategies are required that minimize the potential threat posed by human development to diverse ecosystems and maximize the underlying productivity of protected areas. Reducing the level of threat may require stabilizing the size of the human population, while capturing larger areas of relatively high productivity in the conservation reserve system would lead to greater protection of local diversity.     

Labor Embodied in Trade

Global production chains carry environmental and socioeconomic impacts embodied in each traded good and service. Even though labor and energy productivities tend to be higher for domestic production in high‐income countries than those in emerging economies, this difference is significantly reduced for consumption, when including imported products to satisfy national demand. The analysis of socioeconomic and environmental aspects embodied in consumption can shed a light on the real level of productivity of an economy, as well as the effects of rising imports and offshoring. This research introduces a consumption‐based metric for productivity, in which we evaluate the loss of productivity of developed nations resulting from imports from less‐developed economies and offshoring of labor‐intensive production. We measure the labor, energy, and greenhouse gas emissions footprints in the European Union's trade with the rest of the world through a multiregional input‐output model. We confirm that the labor footprint of European imports is significantly higher than the one of exports, mainly from low‐skilled, labor‐intensive primary sectors. A high share of labor embodied in exports is commonly associated with low energy productivities in domestic industries. Hence, this reconfirms that the offshoring of production to cheaper and low‐skilled, labor‐abundant countries offsets, or even reverts, energy efficiency gains and climate‐change mitigation actions in developed countries.     

Agroecology of Tropical Underground Crops for Small-Scale Agriculture

The important tropical root and tuberous crops cassava (Manihot esculenta), sweet potato (Ipomoea batatas), yams (Dioscorea spp.), and the aroids (especially Xanthosoma and Colocasia spp.) represent an important source of relatively inexpensive carbohydrates to large sectors of the population in tropical areas. One or more tropical root crops are normally a staple in rural communities and are typically grown on small-scale subsistence farms. The current status of the agroecology research on these crops, including productivity under polyculture systems, resource (water, nutrients, light, space) utilization, tolerance to environmental stress, pest dynamics response to habitat manipulation, and alternative cultural practices, is reviewed in this paper as they relate to the performance of these crops in small-scale tropical agricultural systems. The development of technological recommendations to improve the productivity of tropical root crops in the tropics is dependent on an understanding of important underlying agroecological principles. The objective of background ecophysiological work is to develop crop-specific technological packages appropriate to low-input subsistence farming, and to match specific crops with a cropping system that will result in adequate yields and in ecological and socioeconomical sustainability. Because of the close relationship between crops and humans in small-scale farms of the tropics, it is imperative that agroecology research be holistic, multidisciplinary, and cognizant of the many socioeconomic and cultural factors that will determine whether improved technologies will be adopted in any given location.     

Towards representative energy data: the Machiguenga study

Representative energy data for a human population can be produced by combining randomly sampled time allocation observations with activity-specific energy expenditure measurements. Research to produce representative energy data for adults of a population of Machiguenga Indians has recently been conducted in lowland, southeastern Peru. Marked contrast was found between the sexes for average married adults in energy expended on an average day. Men spent about 3,200 kcals and women, about 1,925; ratio: 1.66 to 1. In general, men tended to work at somewhat more energetic activities and for longer periods than did women. In addition to sex-role-related task differences were contrasts in uses of technological items and in respective work settings. These representative behavior data permit direct estimates of population-level energy requirements for average days, seasons, or for 1 year.