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1.
Systems of intensive animal farming, such as the confinement of beef cattle, are widespread in the developed world. Such practices have been under scrutiny since the 1960s for animal welfare and pollution issues. Here, we document the expansion of intensive beef farming to the Brazilian Amazon in order to assess socio-environmental implications. Using a combination of data mining and field surveys, we developed a georeferenced dataset of 201 cattle confinements in the states of Mato Grosso (Cerrado and Amazon biomes), Pará and Rondônia (Amazon biome), collected in 2017. In Mato Grosso, the country’s agribusiness powerhouse, confinements are well established and account for ˜20% of the cattle slaughter. But rapid expansion in Pará and Rondônia remains largely unnoticed due to the absence of data since 2012. We used the new dataset to map cattle confinements across space and time. For the first time, (1) we document an expansion to the Amazon biome; (2) we also show that confinements are associated with substantially higher productivity rates, though intensified pasture-based systems can reach comparable yields; (3) that confinements have crop production levels 2-3 times higher than comparable properties, both in- and out-of-farm; and (4) that confinements tend to slow down on-property deforestation when compared to fattening ranches in the Amazon biome, although off-property effects could be substantial and need further study. Overall, the implications of intensive beef farming for animal welfare and local waste generation in Brazil require attention as pressure to avoid deforestation continues to stimulate the practice.  相似文献   

2.
Further cropland expansion might be unavoidable to satisfy the growing demand for land-based products and ecosystem services. A crucial issue is thus to assess the trade-offs between social and ecological impacts and the benefits of converting additional land to cropland. In the former Soviet Union countries, where the transition from state-command to market-driven economies resulted in widespread agricultural land abandonment, cropland expansion may incur relatively low costs, especially compared with tropical regions.Our objectives were to quantify the drivers, constraints and trade-offs associated with recultivating abandoned cropland to assess the potentially available cropland in European Russia, western Siberia, Ukraine and Kazakhstan—the region where the vast majority of post-Soviet cropland abandonment took place. Using spatial panel regressions, we characterized the socio-economic determinants of cropland abandonment and recultivation. We then used recent maps of changes in cropland to (i) spatially characterize the socio-economic, accessibility and soil constraints associated with the recultivation of abandoned croplands and (ii) investigate the environmental trade-offs regarding carbon stocks and habitat for biodiversity.Less cropland abandonment and more recultivation after 2000 occurred in areas with an increasing rural population and a younger labor force, but also improved yields. Synergies were observed between cropland recultivation and intensification over the 2000s. From 47.3 million hectares (Mha) of cropland abandoned in 2009, we identified only 8.5 (7.1–17.4) Mha of potentially available cropland with low environmental trade-offs and low to moderate socio-economic or accessibility constraints that were located on high-quality soils (Chernozems). These areas represented an annual wheat production potential of ∼14.3 (9.6–19.5) million tons (Mt). Conversely, 8.5 (4.2–12.4) Mha had high carbon or biodiversity trade-offs, of which ∼10% might be attractive for cropland expansion and thus would require protection from recultivation. Agro-environmental, accessibility, and socio-economic constraints suggested that the remaining 30.6 (25.7–30.6) Mha of abandoned croplands were unlikely to provide important contributions to future crop production at current wheat prices but could provide various ecosystem services, and some could support extensive livestock production. Political and institutional support could foster recultivation by supporting investments in agriculture and rural demographic revitalization. Reclaiming potentially available cropland in the study region could provide a notable contribution to global grain production, with relatively low environmental trade-offs compared with tropical frontiers, but is not a panacea to address global issues of food security or reduce land-use pressure on tropical ecosystems.  相似文献   

3.
Multiple cropping, defined as harvesting more than once a year, is a widespread land management strategy in tropical and subtropical agriculture. It is a way of intensifying agricultural production and diversifying the crop mix for economic and environmental benefits. Here we present the first global gridded data set of multiple cropping systems and quantify the physical area of more than 200 systems, the global multiple cropping area and the potential for increasing cropping intensity. We use national and sub-national data on monthly crop-specific growing areas around the year 2000 (1998–2002) for 26 crop groups, global cropland extent and crop harvested areas to identify sequential cropping systems of two or three crops with non-overlapping growing seasons. We find multiple cropping systems on 135 million hectares (12% of global cropland) with 85 million hectares in irrigated agriculture. 34%, 13% and 10% of the rice, wheat and maize area, respectively are under multiple cropping, demonstrating the importance of such cropping systems for cereal production. Harvesting currently single cropped areas a second time could increase global harvested areas by 87–395 million hectares, which is about 45% lower than previous estimates. Some scenarios of intensification indicate that it could be enough land to avoid expanding physical cropland into other land uses but attainable intensification will depend on the local context and the crop yields attainable in the second cycle and its related environmental costs.  相似文献   

4.
Urban growth has received little attention in large-scale land change assessments, because the area of built-up land is relatively small on a global scale. However, this area is increasing rapidly, due to population growth, rural-to-urban migration, and wealth increases in many parts of the world. Moreover, the impacts of urban growth on other land uses further amplified by associated land uses, such as recreation and urban green. In this study we analyze urban land take in cropland areas for the years 2000 and 2040, using a land systems approach. As of the year 2000, 213 Mha can be classified as urban land, which is 2.06% of the earth’s surface. However, this urban land is more than proportionally located on land that is suitable and available for crop production. In the year 2040, these figures increase to 621 Mha, or 4.72% of all the earth’s surface. The increase in urban land between 2000 and 2040 is also more than proportionally located on land that is suitable and available for crop production, thus further limiting our food production capacity. The share of urban land take in cropland areas is highest in Europe, the Middle-East and Northern Africa, and China, while it is relatively low in Oceania and Sub-Saharan Africa. Between 2000 and 2040, urban growth caused the displacement of almost 65 Mton of crop production, which could yield an expansion of up to 35 Mha of new cropland. Land-use planning can influence both the location and the form of urbanization, and thus appears as an important measure to minimize further losses in crop production.  相似文献   

5.
Water harvesting has been widely applied in different social-ecological contexts, proving to be a valuable approach to sustainable intensification of agriculture. Global estimates of the potential of water harvesting are generally based on purely biophysical assessments and mostly neglect the socioeconomic dimension of agriculture. This neglect becomes a critical factor for the feasibility and effectiveness of policy and funding efforts to mainstream this practice. This study uses archetype analysis to systematically identify social-ecological regions worldwide based on >160 successful cases of local water harvesting implementation. We delineate six archetypal regions which capture the specific social-ecological conditions of the case studies. The archetypes cover 19% of current global croplands with hotspots in large portions of East Africa and Southeast Asia. We estimate that the adoption of water harvesting in these cropland areas can increase crop production up to 60–100% in Uganda, Burundi, Tanzania and India. The results of this study can complement conventional biophysical analysis on the potential of these practices and guide policy development at global and regional scales. The methodological approach can be also replicated at finer scales to guide the improvement of rainfed agricultural.  相似文献   

6.
In this article, we evaluate and compare results from three integrated assessment models (GCAM, IMAGE, and ReMIND/MAgPIE) regarding the drivers and impacts of bioenergy production on the global land system. The considered model frameworks employ linked energy, economy, climate and land use modules. By the help of these linkages the direct competition of bioenergy with other energy technology options for greenhouse gas (GHG) mitigation, based on economic costs and GHG emissions from bioenergy production, has been taken into account. Our results indicate that dedicated bioenergy crops and biomass residues form a potentially important and cost-effective input into the energy system. At the same time, however, the results differ strongly in terms of deployment rates, feedstock composition and land-use and greenhouse gas implications. The current paper adds to earlier work by specific looking into model differences with respect to the land-use component that could contribute to the noted differences in results, including land cover allocation, land use constraints, energy crop yields, and non-bioenergy land mitigation options modeled. In scenarios without climate change mitigation, bioenergy cropland represents 10–18 % of total cropland by 2100 across the different models, and boosts cropland expansion at the expense of carbon richer ecosystems. Therefore, associated emissions from land-use change and agricultural intensification as a result of bio-energy use range from 14 and 113 Gt CO2-eq cumulatively through 2100. Under climate policy, bioenergy cropland increases to 24–36 % of total cropland by 2100.  相似文献   

7.
The recent rise in agricultural commodity prices and the expectation that high price will persist have triggered a wave of farmland expansion in regions where land resources are still available. One such region is the former Soviet Union, where the collapse of socialism caused massive agricultural abandonment and where some of these lands are now being brought back into production. Yet, the extent and spatial patterns of recultivation, and what determines these patterns, remains unclear. We examined the extent of recultivation of abandoned agricultural land in Ukraine since 2007 using a new, satellite-based recultivation map and assessed the effect of biophysical and socioeconomic determinants on recultivation patterns using boosted regression trees. We found key predictors of recultivation to be related to the suitability of land for agriculture (i.e., soil quality, temperature). Accessibility to major cities was also important, with most recultivation happening closer to settlements, but this influence varied across Ukraine. Variables related to agricultural management (fertilizer input, mechanization) and demography were negligible in explaining recultivation in our analyses. These factors suggest that recultivation patterns were primarily driven by factors related to land productivity, with recultivation focusing on the most promising areas. Given the remaining large amount of unused agricultural land in Eastern Europe and the former Soviet Union, and considering that much abandonment occurred in areas only marginally suited to agriculture, our findings provide important insights into where recultivation can be expected to happen and thus for assessing the potential socioeconomic and environmental impacts of recultivation.  相似文献   

8.
Soybean farming has brought economic development to parts of South America, as well as environmental hopes and concerns. A substantial hope resides in the decoupling of Brazil's agricultural sector from deforestation in the Amazon region, in which case expansive agriculture need not imply forest degradation. However, concerns have also been voiced about the potential indirect effects of agriculture. This article addresses these indirect effects for the case of the Brazilian Amazon since 2002. Our work finds that as much as thirty-two percent of deforestation, or the loss of more than 30,000 km2 of Amazon forest, is attributable, indirectly, to Brazil's soybean sector. However, we also observe that the magnitude of the indirect impact of the agriculture sector on forest loss in the Amazon has declined markedly since 2006. We also find a shift in the underlying causes of indirect land use change in the Amazon, and suggest that land appreciation in agricultural regions has supplanted farm expansions as a source of indirect land use change. Our results are broadly congruent with recent work recognizing the success of policy changes in mitigating the impact of soybean expansion on forest loss in the Amazon. However, they also caution that the soybean sector may continue to incentivize land clearings through its impact on regional land markets.  相似文献   

9.
Previous estimates of the land area available for future cropland expansion relied on global-scale climate, soil and terrain data. They did not include a range of constraints and tradeoffs associated with land conversion. As a result, estimates of the global land reserve have been high. Here we adjust these estimates for the aforementioned constraints and tradeoffs. We define potentially available cropland as the moderately to highly productive land that could be used in the coming years for rainfed farming, with low to moderate capital investments, and that is not under intact mature forests, legally protected, or already intensively managed. This productive land is underutilized rather than unused as it has ecological or social functions. We also define potentially available cropland that accounts for trade-offs between gains in agricultural production and losses in ecosystem and social services from intensified agriculture, to include only the potentially available cropland that would entail low ecological and social costs with conversion to cropland. In contrast to previous studies, we adopt a “bottom-up” approach by analyzing detailed, fine scale observations with expert knowledge for six countries or regions that are often assumed to include most of potentially available cropland. We conclude first that there is substantially less potential additional cropland than is generally assumed once constraints and trade offs are taken into account, and secondly that converting land is always associated with significant social and ecological costs. Future expansion of agricultural production will encounter a complex landscape of competing demands and tradeoffs.  相似文献   

10.
Greenhouse gas abatement policies will increase the demand for renewable sources of energy, including bioenergy. In combination with a global growing demand for food, this could lead to a food-fuel competition for bio-productive land. Proponents of bioenergy have suggested that energy crop plantations may be established on less productive land as a way of avoiding this potential food-fuel competition. However, many of these suggestions have been made without any underlying economic analysis. In this paper, we develop a long-term economic optimization model (LUCEA) of the U.S. agricultural and energy system to analyze this possible competition for land and to examine the link between carbon prices, the energy system dynamics and the effect of the land competition on food prices. Our results indicate that bioenergy plantations will be competitive on cropland already at carbon taxes about US $20/ton C. As the carbon tax increases, food prices more than double compared to the reference scenario in which there is no climate policy. Further, bioenergy plantations appropriate significant areas of both cropland and grazing land. In model runs where we have limited the amount of grazing land that can be used for bioenergy to what many analysts consider the upper limit, most of the bioenergy plantations are established on cropland. Under the assumption that more grazing land can be used, large areas of bioenergy plantations are established on grazing land, despite the fact that yields are assumed to be much lower (less than half) than on crop land. It should be noted that this allocation on grazing land takes place as a result of a competition between food and bioenergy production and not because of lack of it. The estimated increase in food prices is largely unaffected by how much grazing land can be used for bioenergy production.  相似文献   

11.
Reducing large-scale deforestation in commodity frontiers remains a key challenge for climate change mitigation and the conservation of biodiversity. Public and private anti-deforestation policies have been shown to effectively reduce forest loss, but the conditions under which such policies get adopted are rarely examined. Here we propose a set of conditions that we expect to be associated with the adoption of effective anti-deforestation policies in commodity frontiers. We then examine whether these conditions have influenced policy adoption in South America’s major soy-and-cattle frontiers: the Brazilian Amazon, the Cerrado, the Chaco, the Chiquitano, and Paraguay’s Atlantic Forest. By collating empirical data from diverse sources, including literature review, extensive expert interviews, and analysis of primary and secondary data, we show that the Cerrado, the Chaco, and the Chiquitano differ from the Brazilian Amazon in multiple ways that might have inhibited adoptions of effective anti-deforestation instruments. These conditions include: a higher importance of the agricultural sector within the respective countries, lower carbon stocks and species richness, higher prevalence of private land tenure, and higher baseline compliance with forest reserve regulations on private lands. We also observe that the adoption of the most effective private anti-deforestation instrument, commodity moratoria, may respond to similar conditions as those influencing the adoption of public instruments. Incentivizing public and private actors to adopt effective anti-deforestation policies in the Cerrado, Chaco, and the Chiquitano will likely be more challenging than it has been in the Brazilian Amazon.  相似文献   

12.
Terrestrial vegetation dynamics and global climate controls   总被引:2,自引:0,他引:2  
Monthly data from the moderate resolution imaging spectroradiometer (MODIS) and its predecessor satellite sensors was used to reconstruct vegetation dynamics in response to climate patterns over the period 1983–2005. Results suggest that plant growth over extensive land areas of southern Africa and Central Asia were the most closely coupled of any major land area to El Niño–southern oscillation (ENSO) effects on regional climate. Others land areas strongly tied to recent ENSO climate effects were in northern Canada, Alaska, western US, northern Mexico, northern Argentina, and Australia. Localized variations in precipitation were the most common controllers of monthly values for the fraction absorbed of photosynthetically active radiation (FPAR) over these regions. In addition to the areas cited above, seasonal FPAR values from MODIS were closely coupled to rainfall patterns in grassland and cropland areas of the northern and central US. Historical associations between global vegetation FPAR and atmospheric carbon dioxide (CO2) anomalies suggest that the terrestrial biosphere can contribute major fluxes of CO2 during major drought events, such as those triggered by 1997–1998 El Niño event.  相似文献   

13.
We explore how smallholder agricultural systems in the Kenyan highlands might intensify and/or diversify in the future under a range of socio-economic scenarios. Data from approximately 3000 households were analyzed and farming systems characterized. Plausible socio-economic scenarios of how Kenya might evolve, and their potential impacts on the agricultural sector, were developed with a range of stakeholders. We study how different types of farming systems might increase or diminish in importance under different scenarios using a land-use model sensitive to prices, opportunity cost of land and labour, and other variables. We then use a household model to determine the types of enterprises in which different types of households might engage under different socio-economic conditions. Trajectories of intensification, diversification, and stagnation for different farming systems are identified. Diversification with cash crops is found to be a key intensification strategy as farm size decreases and labour costs increase. Dairy expansion, while important for some trajectories, is mostly viable when land available is not a constraint, mainly due to the need for planting fodders at the expense of cropland areas. We discuss the results in relation to induced innovation theories of intensification. We outline how the methodology employed could be used for integrating global and regional change assessments with local-level studies on farming options, adaptation to global change, and upscaling of social, environmental and economic impacts of agricultural development investments and interventions.  相似文献   

14.
Many global land change scenarios are driven by demand for food, feed, fiber, and fuel. However, novel demands for other ecosystem services give rise to nexus issues and can lead to different land system changes. In this paper we explore the effects of including multiple different demands in land change scenarios. Our reference scenario is driven by demands for crop production, ruminant livestock production, and provisioning of built-up area. We then compare two alternative scenarios with additional demands for terrestrial carbon storage and biodiversity protection, respectively. These scenarios represent possible implementations of globally agreed policy targets. The simulated land system change scenarios are compared in terms of changes in cropland intensity and area, as well as tree and grassland area changes. We find that the carbon and biodiversity scenarios generally result in greater intensification and less expansion of cropland, with the biodiversity scenario showing a stronger intensification effect. However, the impact of setting the targets impacts different world regions in different ways. Overall, both scenarios result in a larger tree area compared to the reference scenario, while the carbon scenario also yields more grassland area. The land systems simulated while accounting for these additional demand types show strong patterns of specialization and spatial segregation in the provisioning of goods and services in different world regions. Our results indicate the relevance of including demands for multiple different goods and services in global land change assessments.  相似文献   

15.
This study develops first-order estimates of water quality co-effects of terrestrial greenhouse gas (GHG) emission offset strategies in U.S. agriculture by linking a national level agricultural sector model (ASMGHG) to a national level water quality model (NWPCAM). The simulated policy scenario considers GHG mitigation incentive payments of $25 and $50 per tonne, carbon equivalent to landowners for reducing emissions or enhancing the sequestration of GHG through agricultural and land-use practices. ASMGHG projects that these GHG price incentives could induce widespread conversion of agricultural to forested lands, along with alteration of tillage practices, crop mix on land remaining in agriculture, and livestock management. This study focuses on changes in cropland use and management. The results indicate that through agricultural cropland about 60 to 70 million tonnes of carbon equivalent (MMTCE) emissions can be mitigated annually in the U.S. These responses also lead to a 2% increase in aggregate national water quality, with substantial variation across regions. Such GHG mitigation activities are found to reduce annual nitrogen loadings into the Gulf of Mexico by up to one half of the reduction goals established by the national Watershed Nutrient Task Force for addressing the hypoxia problem.  相似文献   

16.
Many savannas in West Africa have been converted to croplands and are among the world’s regions most vulnerable to climate change due to deteriorating soil quality. We focused on the savanna-derived cropland in northern Ghana to simulate its sensitivity to projected climate change and nitrogen fertilization scenarios. Here we show that progressive warming–drying stress over the twenty-first century will enhance soil carbon emissions from all kinds of lands of which the natural ecosystems will be more vulnerable to variation in climate variables, particularly in annual precipitation. The carbon emissions from all croplands, however, could be mitigated by applying nitrogen fertilizer at 30–60 kg N ha???1 year???1. The uncertainties of soil organic carbon budgets and crop yields depend mainly on the nitrogen fertilization rate during the first 40 years and then are dominated by climate drying stress. The replenishment of soil nutrients, especially of nitrogen through fertilization, could be one of the priority options for policy makers and farm managers as they evaluate mitigation and adaptation strategies of cropping systems and management practices to sustain agriculture and ensure food security under a changing climate.  相似文献   

17.
中国农田下垫面变化对气候影响的模拟研究   总被引:1,自引:0,他引:1  
曹富强  丹利  马柱国 《气象学报》2015,73(1):128-141
使用同期的美国国家环境预报中心/能源部(NCEP/DOE)再分析资料驱动区域气候耦合模式AVIM-RIEMS2.0,从遥感卫星图像资料中获取3期中国土地利用/覆盖数据中的农田植被类型,将其分别引入到AVIM-RIEMS2.0模式进行积分,研究中国农田下垫面变化对东亚区域气候的影响。结果表明:中国农田变化对气候影响具有冬季弱、夏季强的季节性变化,夏季气温和降水的差异在一些地区通过了95%的显著性检验;20世纪80年代农田扩张,林地、草地为主的植被类型转化为农田,植被变化区域的叶面积指数降低,反照率升高,且通过了95%的显著性检验,使得中国东部地区的气温由南到北呈现增加—减少—增加—减少的相间变化趋势,而降水的变化趋势大体相反;20世纪90年代农田面积减少,除东北地区外,农田变化引起的植被变化与80年代基本相反,叶面积指数变化、反照率以及由此导致的气候各要素也呈现大体相反的变化趋势;不同时期农田变化引起的植被类型转化的差异,使850 hPa风场变化趋势基本相反,可能是导致气温和降水变化趋势差异的主要原因之一。  相似文献   

18.
The global use of and pressure on land resources will continue to rise in tandem with the predicted rise in global population and food demand. Addressing unavoidable trade-offs between satisfying human needs and biodiversity conservation for future generations is of paramount importance when tackling the global environmental challenges of land use. Food consumption patterns are inextricably linked to land-use and land-use changes. The domestic supply and final use of food by humans and feed by animals within the borders of a country have environmental impacts overseas. Countries like Denmark, with considerably high livestock production, import “virtual” land needed to produce cereals and other fodder crops. Denmark's high meat and dairy consumption and trade levels make it a compelling case for this study. The overarching question is: how much land is required to support food and feed consumption in Denmark? This paper assesses the global cropland footprint of Danish food and feed supply from 2000 to 2013 using a consumption-based physical accounting approach. In addition to domestic croplands for local food and supply, we estimate the hectares of cropland displaced in other countries to satisfy Danish demand for food and feed in this period. Secondly, we calculate Denmark's global cropland requirements for the supply of specific livestock products, namely; pork, eggs, beef, milk, and mutton. Globally, animals provide a third of the protein in human diets and agricultural GDP. The total global cropland footprint of Danish food and feed supply decreased by 18% from 1568 kha in 2000 to 1282 kha in 2013 because of a reduction in the consumption of ruminant livestock products. A high share of this reduction can be attributed to increased local self-sufficiency in feed supply as opposed to rising food imports. The share of cropland used for feed in total cropland declined by 5% whereas the share of cropland used for food increased from 28% in 2000 to 32% by 2013. Our findings suggest that reducing domestic meat consumption coupled with local self-sufficiency policies for both food and feed supply could be a means of lowering ecological degradation in exporting countries.  相似文献   

19.
The advancement of South America's agro-pastoral frontier has been widely linked to losses in biodiversity and tropical forests, with particular impacts on the Brazilian cerrado, the Atlantic Forest, and the Amazon. Here we consider an important, yet largely overlooked, driver of South America's soybean expansion, namely the devaluation of local currencies against the US dollar in the late 1990s and early 2000s. Much interest has emerged in recent years over the environmental implications of soybean production in Brazil, with evidence of both direct incursions into moist tropical forest by soybean producers and of potential indirect effects, via the displacement of existing ranching operations. In this research we utilize historical trends in soybean prices, exchange rates, and cropland dedicated to soybean production in Bolivia, Paraguay, and Brazil to estimate the impact of currency devaluations on area of production. The results suggest that approximately 80,000 km2, or 31% of the current extent of soybean production in these countries, emerged as a supply area response to the devaluation of local currencies in the late 1990s. The results also indicate that the more recent depreciation of the dollar and appreciation of the Brazilian real have counteracted a recent rise in global soybean prices, in the process sparing an estimated nearly 90,000 km2 from new cropland, 40,000 km2 of this in the Amazon alone. Amidst an increasingly neoliberal economic environment, where barriers to trade are jettisoned in favor of the free flow of commodities, relative currency values will occupy an important role in the future sourcing of both agricultural expansion and environmental degradation.  相似文献   

20.
The process of global deforestation calls for urgent attention, particularly in South America where deforestation rates have failed to decline over the past 20 years. The main direct cause of deforestation is land conversion to agriculture. We combine data from the FAO and the World Bank for six tropical Southern American countries over the period 1970–2006, estimate a panel data model accounting for various determinants of agricultural land expansion and derive elasticities to quantify the effect of the different independent variables. We investigate whether agricultural intensification, in conjunction with governance factors, has been promoting agricultural expansion, leading to a “Jevons paradox”. The paradox occurs if an increase in the productivity of one factor (here agricultural land) leads to its increased, rather than decreased, utilization. We find that for high values of our governance indicators a Jevons paradox exists even for moderate levels of agricultural productivity, leading to an overall expansion of agricultural area. Agricultural expansion is also positively related to the level of service on external debt and population growth, while its association with agricultural exports is only moderate. Finally, we find no evidence of an environmental Kuznets curve, as agricultural area is ultimately positively correlated to per-capita income levels.  相似文献   

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