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1.
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.  相似文献   

2.
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.  相似文献   

3.
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.  相似文献   

4.
This paper presents an empirical analysis of the human appropriation of aboveground net primary production (aHANPP) in Hungary in the years 1961-2005. In this period aboveground HANPP dropped from 67% to 49% of the potential vegetation's NPP. The trajectory was not smooth, but aboveground HANPP fluctuated with changes in factors affecting agricultural production conditions. Both aboveground net primary production (aNPP) of the prevailing vegetation and harvested aNPP increased during the socialist regime, dropped when the system collapsed and has shown considerable fluctuations since. We discuss the development of aboveground HANPP and the Hungarian land use system in the context of socioeconomic changes during three distinct phases: (1) industrialisation of agriculture (1961-1989), (2) regime collapse (1989-1993) and (3) restructuring of a new economy (1993-2005). Within these periods, different driving factors influenced aboveground HANPP and its constituents. In the phase of industrialisation, mechanisation and agrochemical inputs reduced aHANPP while harvested amounts of biomass increased progressively. In the second phase, political and economic circumstances devastated production conditions resulting in a decline of productivity of actual vegetation and a temporary rise in aboveground HANPP. During the last twelve years, industrialisation patterns of agricultural production recovered. The restructuring of inefficient agricultural production systems raised harvest at moderate levels of agricultural inputs, while climatic conditions intimidated high yield and harvest security. The paper discusses the effect of different economic and political regimes and of major socioeconomic restructuring on the development of the land use system, biomass production and aboveground HANPP.  相似文献   

5.
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.  相似文献   

6.
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.  相似文献   

7.
Human use of biomass has become a major component of the global biogeochemical cycles of carbon and nitrogen. The use of land for biomass production (e.g. cropland) is among the most important pressures on biodiversity. At the same time, biomass is indispensable for humans as food, animal feed, raw material and energy source. In order to support research into these complex issues, we here present a comprehensive assessment of global socioeconomic biomass harvest, use and trade for the year 2000. We developed country-level livestock balances and a consistent set of factors to estimate flows of used biomass not covered by international statistics (e.g. grazed biomass, crop residues) and indirect flows (i.e. biomass destroyed during harvest but not used). We found that current global terrestrial biomass appropriation amounted to 18.7 billion tonnes dry matter per year (Pg/yr) or 16% of global terrestrial NPP of which 6.6 Pg/yr were indirect flows. Only 12% of the economically used plant biomass (12.1 Pg/yr) directly served as human food, while 58% were used as feed for livestock, 20% as raw material and 10% as fuelwood. There are considerable regional variations in biomass supply and use. Distinguishing 11 world regions, we found that extraction of used biomass ranged from 0.3 to 2.8 t/ha/yr, per-capita values varied between 1.2 and 11.7 t/cap/yr (dry matter). Aggregate global biomass trade amounted to 7.5% of all extracted biomass. An analysis of these regional patterns revealed that the level of biomass use per capita is determined by historically evolved patterns of land use and population density rather than by affluence or economic development status. Regions with low population density have the highest level of per-capita biomass use, high-density regions the lowest. Livestock, consuming 30-75% of all harvested biomass, is another important factor explaining regional variations in biomass use. Global biomass demand is expected to grow during the next decades; the article discusses some options and possible limitations related to such a scenario.  相似文献   

8.
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.  相似文献   

9.
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.  相似文献   

10.
Real production systems are often vertically integrated in thesense that one production process uses the unwanted joint product of another production process as input.This interrelationship links in a non-obvious way the different negative externalities stemming from theproduction processes. An empirical example is the sulphuric acid industry. Our model of a vertically integratedproduction system shows how internalising one currently existing externality may create another externalitywhich has thus far not been existent. We also discuss how environmental policy could deal with this problemwhen regulating integrated production systems.  相似文献   

11.
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.  相似文献   

12.
For the period 1991-2005 inclusive we categorise peer-reviewed journal output depending on whether it pertains to case-studies in a) cropland or b) aggregate semi-natural and natural terrestrial (ASNNT) ecosystems for three applications in ecological modelling: 1) modelling of terrestrial carbon and nitrogen fluxes; 2) modelling of terrestrial root systems; 3) geographic information systems. Next we compare these research output magnitudes for case-studies in cropland and ASNNT ecosystems with estimates of the total economic value (TEV) of either system.For applications 1) and 3) the magnitude of research output for ASNNT ecosystems between 1991-2005 is greater than for cropland and research into the former is increasing at a faster rate over time compared to the latter. Given that the TEV of ASNNT ecosystems is 82 times greater than the TEV of cropland we deem these trends in research output as desirable under the assumption that value and research should be interdependent. However for application 2), although research into ASNNT ecosystems is increasing at a faster rate compared to cropland, total research output between 1991-2005 is greater for cropland. We conclude that increased research output which focuses on ASNNT ecosystems in this particular application should be a priority, given the high TEV of ASNNT ecosystems relative to cropland.  相似文献   

13.
The role of production technology for sustainable economic growth and resource management in the multispecies renewable resources industries is a neglected issue, particularly in complex tropical ecosystems. Given the still rudimentary understanding of biological interactions among species, even in most temperate ecosystems, the importance of under-standing the technological and economic interactions is heightened for sustainable economic growth and public regulation. This paper evaluates these interactions for the multiproduct gill net fisheries of Peninsular Malaysia. Standard price and quantity controls may have little promise. Gear regulations, a policy of constant escapement, and managing the entire mix of species as a single stock for economic rather than biomass yield appear the most promising management tools given the limited regulatory options.  相似文献   

14.
目前学界对于"资本"大致持两种研究视角,即将其视为一种生产要素或一种生产关系,由此,资本作用于地方发展的地理学研究也存在发展地理学和社会文化地理学两种对应的研究视角。随着关于地方发展的研究不断深进,两种研究视角逐渐非线性地交互作用,亟待在一个整合框架下提出新的综合范式,以推进地方发展研究的理论创新和实践分析。基于此,文章重新梳理了发展地理学和社会文化地理学两个学科视角下的资本与地方发展之间的相关研究,认为可以在场域空间视阈下将两个视角整合在同一个诠释框架之中,并基于该整合框架提出三个未来应关注的研究要点。文章的相关分析有利于推进当前中国发展战略的实施,且尝试提高中国人文地理学对于空间—区域发展问题的理论解释力。  相似文献   

15.
城市化过程中的流动人口,农村内部农地调整以及农用土地非农化问题是现阶段中国转轨与经济发展过程中面临的重大问题。这三方面问题具有非常紧密的关联,需要一个整体思路来进行分析,更需要在此基础上给出系统、具操作性的解决方案。本文在对这些问题及其政策关联性进行剖析的基础上,揭示了中国户籍制度与农地制度改革在一个大国的转轨与经济发展过程中的特殊性,并提出一个政策组合,试图在改革现有土地征用制度的同时,通过给予农民在土地和城镇社会保障之间的自由选择权建立起一种良性的城市化机制,从而实现户籍制度和农地制度改革的突破。  相似文献   

16.
基于BP神经网络的征地区片综合地价评估   总被引:2,自引:1,他引:2  
夏建国  申文金 《经济地理》2007,27(6):1015-1017
文章提出了征地区片综合地价的BP神经网络系统的基本构造,并在充分考虑城市规划和生活水平对征地区片土地价格影响的基础上,对神经网络的评估系统进行了设计.给出了征地区片综合地价评估的指标体系及特征指标的量化计算公式.以雅安市雨城区最新的征地区片综合地价为基础,利用改进的BP神经网络模型对它们进行了训练和模拟,取得了良好的模拟结果,证明了ANN法用来测算征地区片综合地价的可行性和先进性.  相似文献   

17.
Climate change and its consequences present one of the most important threats to biodiversity and the functions of ecosystems. The stress on biodiversity is far beyond the levels imposed by the natural global climatic changes occurring in the recent evolutionary past. It includes temperature increases, shifts of climate zones, melting of snow and ice, sea level rise, droughts, floods, and other extreme weather events. Natural systems are vulnerable to such changes due to their limited adaptive capacity. Based on an analysis using the DPSIR framework, this paper discusses some of the important socio-economic driving forces of climate change, with a focus on energy use and transportation. The paper also analyses observed and potential changes of climate and the pressures they exert on biodiversity, the changes in biodiversity, the resulting impacts on ecosystem functions, and possible policy responses. The latter can be divided into mitigation and adaptation measures. Both strategies are needed, mitigation in order to stabilise the greenhouse gas concentrations in the atmosphere, and adaptation in order to adjust to changes that have already occurred or cannot be avoided. One mitigation option, increased biofuel production, which is also a response to oil depletion, would change land use patterns and increase human appropriation of net primary production of biomass, thereby threatening biodiversity. By considering the first order and second order impacts of climate change on biodiversity when developing policy measures, it will be possible to integrate ecosystem and biodiversity protection into decision-making processes.  相似文献   

18.
Ecosystem services valuation has achieved considerable prominence in research and policy circles in recent years. This paper reviews the studies that have tried to estimate the value of forest ecosystem services. Broadly, this study addresses the following questions: (1) What insights do these studies provide on the value of forest ecosystems? (2) What lessons do they offer from an economic and policy perspective? (3) What are the shortcomings of the existing studies, and what are the challenges and issues for future research? Evidence from a cross section of forest sites, countries and regions suggests that not only the total valuation of ecosystem services varies widely across studies but also the valuation of individual services. This variation suggests that policies to conserve ecosystems and their services should emphasise local contexts and values. This paper concludes by discussing the shortcomings of existing studies, and suggests that, among other things, future research should focus on the neglected ecosystem services, ‘disservices’, assess the role of dynamic factors and environmental catastrophes on the provision of ecosystem services, and assess the benefits of keeping forests intact versus converting them to alternative uses.  相似文献   

19.
Co-operatives in North America, developed to correct or off set real or imagined wrongs in the economic system within which agriculture over time became further involved, have remained largely rural. Where successful, co-operatives bridged the gap between a fundamentalist agricultural production industry that tended to look inwards to itself and a privately capitalised marketing industry that looked outwards towards metropolitan and overseas markets. In pioneer and pioneering environments where free enterprise agri-business became significantly involved in on-farm or on-ranch operations, co-operatives did not become im-portant as the services and attitudes of agri-business complemented rather than exploited the man on the land. In the more commercialised integrated agriculture of today, corporate agri-business has found an interest in greater involvement in farm operations: much of this comes from changes in technology that make off-farm purchases as important a component of the agricultural com-plex as off-farm sales of products. Thus, co-operatives have lost their unique “bridge” role, have problems themselves of identity and of their most desirable patterns of future development. But their competition-existing corporate agri-business and new entrants from the conglom-erate industrial giants-are not without their problems also. These are outlined as well as the issues co-operatives-and co-operative philosophers and promoters-must tackle if they are to remain successful market participants and have identifiable characteristics that reflect co- operative idealism. The unique member-client relationship the co-operative is based on should be exploited to maintain and expand these complementary and essential goals for continued farmers’business participation in the North American and world economies.  相似文献   

20.
农村宅基地流转的模式与路径研究   总被引:12,自引:0,他引:12  
刘卫柏  贺海波 《经济地理》2012,32(2):127-132
通过横向比较分析后认为:我国农村宅基地流转存在管理制度缺陷、村庄规划滞后、基层监管欠缺等问题。在对我国农村宅基地流转进行实证调研后,总结出我国农村宅基地流转模式主要有村集体经济组织内部转让、外部转让、农户自由转让、地方政府主导转让等几种类型,在此基础上提出推动农村宅基地流转的对策建议。  相似文献   

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