Human appropriation of net primary production in the United Kingdom, 1800-2000 : Changes in society's impact on ecological energy flows during the agrarian-industrial transition

This paper presents an empirical analysis of the United Kingdom's society's long-term intervention into the energy flows of domestic terrestrial ecosystems through the human appropriation of aboveground net primary production (aHANPP) covering the period 1800-2000. The depicted aHANPP trajectory and the historical development of its components are discussed in view of a continuously increasing population and the transition process from an agrarian to an industrial socioecological regime. During the 19th century, aHANPP shows a steady decline from its level of 71% in 1800. While even higher levels were reached during the mid 20th century, the trend during the last forty years of the period under investigation again shows a reduction of aHANPP, which lies at 68% in the year 2000. The high values of aHANPP in the United Kingdom are primarily attributable to the limited amount of forest in comparison to large agricultural areas. At the beginning of the studied period, the relative stabilisation or even decrease in aHANPP in comparison to population development was made possible through the area expansion of and productivity increases on cropland and permanent pastures. Later this was made possible through the outsourcing of biomass harvest, by satisfying local nutritional demands by means of overseas imports, and as from the mid 20th century through huge amounts of fossil fuel based inputs into agriculture (e.g. increased amounts of fertilizers and motorized traction) which allowed increases in biomass harvest to be decoupled from HANPP.     

Human appropriation of aboveground net primary production in Spain, 1955-2003: An empirical analysis of the industrialization of land use

The human appropriation of net primary production (HANPP) is an indicator of the human domination of ecosystems that measures to which extent human activities alter the amount of biomass available each year in ecosystems. This paper analyses the development of aboveground HANPP (aHANPP) in Spain for the period from 1955 to 2003. During this period, Spain's agriculture underwent a transition from a largely pre-industrial to a highly intensified production system. Changes in land use patterns include a reduction of cropland area and an expansion of forest area. Results show that aHANPP declined from 67% of potential aNPP in 1955 to 61% in 2003. Biomass harvest strongly increased from 68 million tons dry matter biomass per year (Mt/yr) to 106 Mt/yr, with nearly all of this increase occurring on cropland. Productivity losses due to human-induced land conversions dropped significantly from 112 Mt/yr to 63 Mt/yr, mainly as a result of the surge in cropland productivity and the increase in forest area. Despite its decrease during the last decades, aHANPP in Spain is still at a remarkably high level in comparison with the global average or other industrialized countries.     

Trajectories in human domination of ecosystems: Human appropriation of net primary production in the Philippines during the 20th century

The “human appropriation of net primary production” (HANPP) has been suggested as a comprehensive indicator to measure impacts of human land use on ecosystems. It accounts for (a) human-induced changes in biological productivity and (b) biomass harvest. This study presents an analysis of aboveground HANPP in the Philippines between 1910 and 2003, a period characterized by massive deforestation and increases in land use intensity and biomass extraction. Results show a steep increase of aboveground HANPP from just below 35% of potential productivity in 1910 to slightly above 60% in 1970 and constant values since then. Large-scale changes in land cover and agricultural practices were the main direct determinants of this trajectory in HANPP. Remarkably, HANPP grew at much slower pace than population did: While the amount of NPP appropriated by humans doubled throughout the period, population increased by a factor ten. Increasing efficiency in terms of biomass extraction per unit of area, relying on ever-increasing inputs, and changes in the nation's physical biomass trade balance were of major importance for this difference in growth rates. In the coming decades, the Philippines will have to face the challenge to meet increases in biomass demand without putting even higher strains on the ecosystems.     

Embodied HANPP: Mapping the spatial disconnect between global biomass production and consumption

Biomass trade results in a growing spatial disconnect between environmental impacts due to biomass production and the places where biomass is being consumed. The pressure on ecosystems resulting from the production of traded biomass, however, is highly variable between regions and products. We use the concept of embodied human appropriation of net primary production (HANPP) to map the spatial disconnect between net-producing and net-consuming regions. Embodied HANPP comprises total biomass withdrawals and land use induced changes in productivity resulting from the provision of biomass products. International net transfers of embodied HANPP are of global significance, amounting to 1.7 PgC/year. Sparsely populated regions are mainly net producers, densely populated regions net consumers, independent of development status. Biomass consumption and trade are expected to surge over the next decades, suggesting a need to sustainably manage supply and demand of products of ecosystems on a global level.     

The global loss of net primary production resulting from human-induced soil degradation in drylands

Land degradation, the temporary or permanent reduction of land's productive capacity resulting from poor land management, has gained considerable attention as an environmental and development issue of global importance, in particular in the Earth's drylands. This study presents a global estimate of net primary production (NPP) losses caused by human-induced dryland degradation. Due to the large uncertainties related to international databases on dryland degradation, we compiled a world map of the extent and degree of desertification based on existing regional and global maps. Two distinct approaches were followed in order to estimate NPP losses due to degradation on drylands: in the first approach, we combined these maps with model results on global potential NPP, determined with the LPJ-DGVM, with a set of factors on NPP losses per degradation degree, derived from the literature. In a second approach, we made use of spatially explicit information on potential and current NPP of agricultural areas obtained from a global HANPP assessment [Haberl, H., Erb, K.-H., Krausmann, F., Gaube, V., Bondeau, A., Plutzar, C., Gingrich, S., Lucht, W. and Fischer-Kowalski, M., 2007. Quantifying and mapping the human appropriation of net primary production in earth's terrestrial ecosystems. Proceedings of the National Academy of Sciences of the United States of America, 104: 12942-12947.]. We used the difference between potential and current NPP on croplands situated in drylands in order to quantify the effect of dryland degradation on NPP. NPP losses were found to range between 799 and 1936 Tg C/yr in the first approach, and to amount to 965 Tg C/yr in the second approach. Overall, approximately 2% of the global terrestrial NPP are lost each year due to dryland degradation, or between 4% and 10% of the potential NPP in drylands. NPP losses amount to 20-40% of the potential NPP on degraded agricultural areas in the global average and above 55% in some world regions. The results reveal that the contributions of dryland degradation to the total HANPP in drylands is of similar dimension than the overall annual socioeconomic biomass harvest. Accordingly, strategies aimed at reducing dryland degradation could present promising options to sustain future population numbers without putting further pressures on dryland ecosystems.     

Analyzing the global human appropriation of net primary production — processes, trajectories, implications. An introduction

Humanity's role in shaping patterns and processes in the terrestrial biosphere is large and growing. Most of the earth's fertile land is used more or less intensively by humans for resource extraction, production, transport, consumption and waste deposition or as living space. Biomass production on cropland, grazing areas and in managed forests dominates area requirements, but other processes such as soil degradation, human-induced fires and expansion of settlements and infrastructure play an increasingly important role as well. The growing human domination of terrestrial ecosystems contributes to biodiversity loss as well as to a reduced capability of ecosystems to deliver vital services such as buffering capacity, soil conservation or self-regulation. This special section is devoted to the presentation of recent research into the patterns, determinants and implications of the human appropriation of net primary production (HANPP), an integrated socio-ecological indicator of land use intensity. By measuring the combined effect of land conversion and biomass harvest on the availability of trophic energy (biomass) in ecosystems, HANPP explicitly links natural with socioeconomic processes and allows for integrated analyses of land systems. This introductory article explains the rationale that links current HANPP research to Ecological Economics and discusses issues of definition and methods shared by all articles included in the special section. Finally, it gives an overview of the individual papers, provides some general conclusions and presents an outlook for future research: a better understanding of long-term trajectories of HANPP, of the significance of trade patterns as well as of the future role of bioenergy are highlighted as important issues to be addressed in the coming years.     

Biomass consumed in anthropogenic vegetation fires: Global patterns and processes

Human-induced vegetation fires destroy a large amount of biomass each year and thus constitute an important fraction of the human interference with the energy flows of terrestrial ecosystems. This paper presents a quantification of the biomass burned in large-scale as well as small-scale human-induced vegetation fires at the country level for the year 2000. The amount of biomass burned in large scale fires is estimated combining information on the amount of biomass destroyed by large vegetation fires each year, derived by remote sensing, with estimates about the fraction induced by human activities. For biomass flows resulting from shifting cultivation, no comprehensive information is available at the global scale. Therefore, this flow was modelled on the basis of data on the area subjected to shifting cultivation and assumptions about the typical length of the cropping and fallow periods and the amount of biomass destroyed in each rotation cycle. The results show that the amount of biomass consumed in anthropogenic vegetation fires ranges between 3.5 and 3.9 billion tons dry matter per year (Pg dm/yr), a considerable amount when compared to the global socioeconomic biomass harvest of 12 Pg dm/yr. One third of the biomass consumed in anthropogenic fires each year, 1.0-1.4 Pg dm, results from shifting cultivation. Anthropogenic fires are most important in the regions of Sub-Saharan Africa (2202 Tg dm/yr), Latin America (795 Tg dm/yr), South-Eastern Asia (336 Tg dm/yr) and Central Asia (157 Tg dm/yr), whereas in regions dominated by industrialized countries, anthropogenic vegetation fires play a minor role. Due to the lack of consistent and spatially explicit data for the year 2000, these numbers do not include agricultural residues burned in the field. The inclusion of residue burning in the year 1985 would increase the total biomass consumed by 0.45 Pg dm to a total of between 4.0 and 4.4 Pg dm/yr. The paper shows that the current geographic pattern of biomass burning can be explained by a combination of natural factors, such as the type of the potential vegetation, and socioeconomic factors, such as population density and the degree of industrialization of a region, which ultimately determine the application of vegetation fires in land use management. It is expected that the magnitude of anthropogenic vegetation fires will decrease in absolute and relative terms, mainly due to population growth and the diffusion of modern land use technologies, which more and more replace the function of vegetation fires as a land management tool.     

Towards an integrated model of socioeconomic biodiversity drivers, pressures and impacts. A feasibility study based on three European long-term socio-ecological research platforms

Effective policies to slow the rate of anthropogenic biodiversity loss should reduce socioeconomic pressures on biodiversity, either directly or by modifying their underlying socioeconomic driving forces. The design of such policies is currently hampered by the limited understanding of socioeconomic drivers of and pressures on biodiversity as well as by lacking data, indicators and models. In order to improve understanding of these issues we here propose a conceptual model of socioeconomic biodiversity drivers and pressures. The model is based on the drivers-pressures-impacts-states-responses (DPSIR) scheme and on the socioeconomic metabolism approach. The aim of the model is to guide research aimed at improving our understanding of socioeconomic biodiversity pressures and drivers and to serve as a basis for the development of formal, quantitative models in that field. Based on three European long-term socio-ecological research (LTSER) platforms, we analyze the model's applicability and suitability as well as data availability and research needs. These platforms are the Danube Delta Wetland System in Romania, the Doñana in Spain and the Eisenwurzen in Austria. An empirical analysis of the relationship between the human appropriation of net primary production (HANPP) and breeding bird richness in the Eisenwurzen demonstrates the ability of HANPP to provide a link between socioeconomic pressures/drivers and biodiversity. The analysis of the case studies underlines the potential utility of the conceptual model to guide future research into socioeconomic biodiversity drivers and pressures. However, considerable investments in monitoring and reconstruction of past trajectories as well as in model development will be required before mathematical (computer) models of the interrelation processes between society and ecosystems can be successfully deployed.     

Non-consumptive values and optimal marine reserve switching

A bioeconomic model is constructed to analyze spatial harvesting and the effects of marine reserve “switching” between a “no-take” area and a harvested area while accounting for both harvesting/consumptive and also non-consumptive values of the fishery. Using estimated parameters from the red throat emperor fishery from the Great Barrier Reef, simulations show that an optimal switching strategy can be preferred to a fixed reserve regime, but is dependent on spillovers from reserves to harvested areas, the nature of shocks to the environment, the size of the non-consumptive values and how they change with the biomass, and the sensitivity of profits to the harvest and biomass. Importantly, the results show that how non-consumptive values change with the size of the fishery substantially affects both the returns from switching and the optimal closure time.     

Agricultural Efficiency Gains in Centrally Planned Economies

This paper estimates the growth of agricultural production efficiency in nine centrally planned economics over two time periods, 1965-1977 and 1978-1989. The second time period was one of agricultural policy reform for most of the nine countries. Our major finding is that production efficiency improved in the second time period, helping to check a fall in growth of agricultural output. Gains in production efficiency were as large in Central and Eastern Europe as the gains in China, even though economic reforms were deeper in China, where production was privatized. The slowdown in growth of agricultural production in the 1980′s was not due to production inefficiencies, but rather due to slower growth of inputs, particularly fertilizer. The implication of our results is that privatization of farming may be unnecessary in order to achieve high production efficiency gains. J. Comp. Econom., June 1994, 18(3), pp. 000-000, University of California, Davis, California 95616.     

To settle or protect? A global analysis of net primary production in parks and urban areas

We test—at the global scale—the hypothesis that human beings tend to build settlements in areas of high biological productivity, and protect (as parks) areas of low productivity. Furthermore, we propose an alternative measure of the extent and effectiveness of the global protected areas network based on potential net primary production (NPP₀). The average NPP₀ in urban areas and parks is calculated and compared to the average NPP₀ of the geopolitical regions and biomes containing these areas. Additionally, human appropriation of net primary production (HANPP) in parks is used as an indicator of the effectiveness of these protected areas. We find that in almost all regions of the world, humans have chosen to settle in the most productive areas. At the global scale, urban areas have considerably higher NPP₀ (592 g Cm^− 2 yr^− 1) than the global average (494 g Cm^− 2 yr^− 1), while parks have roughly average NPP₀ (490 g Cm^− 2 yr^− 1). Parks with an IUCN category of I-VI account for 9.5% of the planet's terrestrial NPP₀, compared to 9.6% of its terrestrial area. Although protected area and protected NPP₀ are nearly equal, this equivalence is diminished by HANPP within parks. Globally, the average HANPP in all protected areas is 14% of their NPP₀, and HANPP within parks increases as the park management category becomes less restrictive. Moreover, we find a positive correlation between HANPP in parks and the extent of urbanization in the surrounding region and biome. Area-based targets for conservation provide no information on either the quality of the areas we choose to protect, or the effectiveness of that protection. We conclude that NPP₀ and HANPP may provide an additional, useful tool for assessing the extent and effectiveness of the global protected areas network.     

Harvest and extinction in multi-species ecosystems

A potential cost of harvesting in multi-species ecosystems is the extinction of nonharvested species that are at the same trophic level as the harvested species. Existing analytical models are not well-suited for studying this harvest externality because they focus on species interactions across trophic levels instead of within them. We identify the conditions under which the harvesting of a single species causes at least one extinction of nonharvested species at the same trophic level. We compare two harvest regimes: uniform management, in which a privately optimal harvest rate is applied to the entire ecosystem; and specialized management, in which a portion of the ecosystem is intensively managed for the harvested species and the rest is left unharvested. Which regime is more likely to result in extinction depends on the discount rate and on the harvested species' competitive ability and colonization rate compared to those of the other species.     

农业投入品价格上涨对我国园艺产品收益影响的经济计量分析——以柑橘为例

采用1989～2006年的时序数据,通过建立向量自回归模型考量我国农业投入品价格上涨与柑橘收益之间的动态影响关系,并在对VAR模型进行残差检验和稳定性检验的基础上,运用脉冲响应函数和预测方差方法进行经济计量分析。研究结果表明,柑橘每亩纯收益对农业投入品价格上涨有负向响应并趋向稳定;农业投入品价格上涨对柑橘每亩纯收益增长有正向响应并趋向稳定。为有效缓解我国农业投入品价格大幅度上涨对柑橘收益产生负面影响,政府应健全农业投入品调控机制,取消农业投入品生产和流通环节的补贴政策,对农民实行直接补贴;建立中央和地方两级农业投入品储备制度,平抑农业投入品市场价格季节性波动;完善农业投入品连锁经营体系,降低农业投入品流通成本。     

HAVE PRICE POLICIES DAMAGED LDC AGRICULTURAL PRODUCTIVITY?

This paper examines price policies and agricultural productivity in 18 developing countries over the period 1961–1985. We measure productivity with both a nonparametric Malmquist index and a production function, confirming previous findings of declining agricultural productivity, but with sufficient inconsistencies as to raise concern about the adequacy of the methods. We nonetheless find considerable support for the hypothesis that unfavorable price policies have damaged agricultural productivity performance in these countries. (JEL 04, Ql)     

The Intersectoral Terms of Trade and Their Impact on Urbanisation in China

The historical experience of developed countries shows that the economic development process and accompanying urbanisation represent a structural transformation from an economy dominated by agriculture to one dominated by non-agricultural activities. Therefore it is generally believed that the agricultural sector needs to make a net transfer of resources, both capital and labour, to other sectors in the processes of economic transformation and urbanisation. However, the process of urbanisation in a socialist economy can be negatively affected by its pattern of resource generation. On the basis of an analysis of the 'scissors' pricing mechanism to which the state had recourse for financing its industrialisation, this article argues that this kind of resource transfer did not necessarily favour a high rate of urban employment and urbanisation, regardless of the magnitude of the seizure of resources from the agricultural sector.     

Cuba's New Sugarcane Cooperatives Ten Years Later

The break-up of the state monopoly on land was the most important agricultural policy of Cuba's 1993–95 economic reform process. A new form of agricultural organization replaced the inefficient sugarcane state farm: the Basic Unit of Cooperative Production (UBPC). Official data released at the end of 2003 were used to evaluate the economic performance of the new cooperatives after the first ten years. The first result shows an average rate of decline in the number of UBPC of around 60 units per year. Parameters measuring production also show average annual negative rates of decline: 38,800 harvested hectares, and 860,000 tons of sugarcane. Agricultural yields remained stable during the study period. Other important indicators such as revenue, cost and profitability also show negative trends. Factors that appear to be limiting efficiency and profitability include, among others, a timid system of material incentives, lack of autonomy, excessive governmental control over input and product markets, and absence of foreign investment.     

农业生产资料投入对粮食作物产出影响因素的相关验证分析

农业生产资料价格上涨,导致农民对农业生产的资源配置、作物结构以及投入结构进行调整,以优化生产成本,这将进一步影响相关粮食作物的产出。应用C—D生产函数的扩展形式,分析农业生产资料各投入要素变化,对粮食作物产出的影响程度。化肥施用量和农业劳动力数是影响粮食产出的两个主要因素,进而提出了推广科学施肥,提高化肥利用率、大力推广农业机械化技术的应用、加大国家对农业基础建设和科研开发与推广的投资力度等保障措施,来进一步促进粮食生产稳步增长。