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1.
The expansion of biofuel production can lead to an array of negative environmental impacts. Therefore, the European Union (EU) has recently imposed sustainability criteria on biofuel production in the Renewable Energy Directive (RED). In this article, we analyse the effectiveness of the sustainability criteria for climate change mitigation and biodiversity conservation. We first use a global agriculture and forestry model to investigate environmental effects of the EU member states National Renewable Energy Action Plans (NREAPs) without sustainability criteria. We conclude that these targets would drive losses of 2.2 Mha of highly biodiverse areas and generate 95 Mt CO 2 eq of additional greenhouse gas (GHG) emissions. However, in a second step, we demonstrate that the EU biofuel demand could be satisfied ‘sustainably’ according to RED despite its negative environmental effects. This is because the majority of global crop production is produced ‘sustainably’ in the sense of RED and can provide more than 10 times the total European biofuel demand in 2020 if reallocated from sectors without sustainability criteria. This finding points to a potential policy failure of applying sustainability regulation to a single sector in a single region. To be effective this policy needs to be more complete in targeting a wider scope of agricultural commodities and more comprehensive in its membership of countries.  相似文献   

2.
Agriculture faces serious problems in feeding 9 billion people by 2050: production must be increased and ecosystem services maintained under conditions for growing crops that are predicted to worsen in many parts of the world. A proposed solution is sustainable intensification of agriculture, whereby yields are increased on land that is currently cultivated, so sparing land to deliver other ecosystem services. Genetically modified (GM) crops are already contributing to sustainable intensification through higher yields and lower environmental impacts, and have potential to deliver further significant improvements. Despite their widespread successful use elsewhere, the European Union (EU) has been slow to introduce GM crops: decisions on applications to import GM commodities are lengthy, and decision-making on applications to cultivate GM crops has virtually ceased. Delayed import approvals result in economic losses, particularly in the EU itself as a result of higher commodity prices. Failure to grant cultivation approvals costs EU farmers opportunities to reduce inputs, and results in loss of agricultural research and development from the EU to countries such as the United States and China. Delayed decision-making in the EU ostensibly results from scientific uncertainty about the effects of using GM crops; however, scientific uncertainty may be a means to justify a political decision to restrict cultivation of GM crops in the EU. The problems associated with delayed decision-making will not improve until there is clarity about the EU's agricultural policy objectives, and whether the use of GM crops will be permitted to contribute to achieving those objectives.  相似文献   

3.
4.
农作物遗传多样性农家保护的现状及前景   总被引:32,自引:1,他引:31  
农作物地方品种的有效保护是农业生物多样性的可持续利用的基础。由于现代农业的集约化生产方式使大量农作物地方品种被少数高产改良品种所取代,造成农作物基因库的严重“基因流失”(genetic erosion)。农家保护是在农业生态系统中进行的动态保护,被保护的生物多亲性可在其生境中继续进化而产生新的遗传变异,在而是农业生物多样性就地保护的重要途径。然而,尽管人们对作物品种资源农家保护的兴趣不断增长,也有大量有关农家的保护的研究和案例分析,但目前为止还没有比较成功的农家保护实例报道。因此,对农家保护的机制及科学问题进行深入的研究,并寻求一条新的途径来充分发挥农家保护应有的作用,显得格外重要。利用生物多样性布局的水稻混合间栽的生产模式,不仅解决了病害控制的问题,而且也保护了水稻地方品种的多样性。这种混合间栽的生物多样性布局和生产方式可能成为农保护的一条新途径。  相似文献   

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6.
Bees are in decline potentially leading to reduced pollination and hence production of insect-pollinated crops in many countries. It is however still unclear whether the consequences of pollinator shortages differ among countries with different environmental and societal conditions. Here, we calculated economic gains attributed to insect (particularly bee) pollination (EVIP) as well as their contribution to the total value of crop production (vulnerability), and analyzed their temporal trends and inter-annual variability from 1991 to 2009 for each country of the European Union (EU). To understand which factors drive country-specific differences in pollinator dependency and stability of insect-dependent crop yields, we further asked whether EVIP, vulnerability and stability of yields were influenced by a country's climate, the number of wild bee species and/or managed honeybee hives per country, and (agricultural) gross domestic product (GDP).Across Europe, crop pollination by insects accounted for 14.6 [±3.3] billion EUR annually (EVIP), which equaled 12 (±0.8)% of the total economic value of annual crop production. Gains strongly varied among countries. Both EVIP and vulnerability increased (and the inter-annual variation of vulnerability decreased) significantly from the colder northern to the warmer Mediterranean EU countries, in parallel with increases in the number of wild bee species. Across years, economic importance of pollination increased in all but three EU countries. Apples were the most important insect-pollinated crop in the EU, accounting for 16% of the EU's total EVIP. Our results show that whereas dependency on insect pollination increased from the colder north to the warmer south, variation in economic gain from insect pollination decreased, indicating that Mediterranean countries had more stable yields of pollinator-dependent crops across years and thus more reliable gains from pollination services.  相似文献   

7.
A major concern related to the adoption of genetically modified (GM) crops in agricultural systems is the possibility of unwanted GM inputs into non-GM crop production systems. Given the increasing commercial cultivation of GM crops in the European Union (EU), there is an urgent need to define measures to prevent mixing of GM with non-GM products during crop production. Cross-fertilization is one of the various mechanisms that could lead to GM-inputs into non-GM crop systems. Isolation distances between GM and non-GM fields are widely accepted to be an effective measure to reduce these inputs. However, the question of adequate isolation distances between GM and non-GM maize is still subject of controversy both amongst scientists and regulators. As several European countries have proposed largely differing isolation distances for maize ranging from 25 to 800 m, there is a need for scientific criteria when using cross-fertilization data of maize to define isolation distances between GM and non-GM maize. We have reviewed existing cross-fertilization studies in maize, established relevant criteria for the evaluation of these studies and applied these criteria to define science-based isolation distances. To keep GM-inputs in the final product well below the 0.9% threshold defined by the EU, isolation distances of 20 m for silage and 50 m for grain maize, respectively, are proposed. An evaluation using statistical data on maize acreage and an aerial photographs assessment of a typical agricultural landscape by means of Geographic Information Systems (GIS) showed that spatial resources would allow applying the defined isolation distances for the cultivation of GM maize in the majority of the cases under actual Swiss agricultural conditions. The here developed approach, using defined criteria to consider the agricultural context of maize cultivation, may be of assistance for the analysis of cross-fertilization data in other countries.  相似文献   

8.
Nitrogen (N) use in European agriculture is not efficient, with less than one third of available N recovered in intended outputs. Over two thirds of N is lost to the environment, where it has negative ecological, social and economic consequences. Improving N efficiency in crop and animal production is a priority to reduce its detrimental effects while maintaining food production. The territory scale is particularly suitable for evaluation of N efficiency because it is used for environmental impact assessment and public policies. However, N Use Efficiency (NUE), the efficiency indicator available at this scale, has several limitations: (i) inputs and outputs can vary depending on the boundaries and definitions used, (ii) input production and transport are not always included, and (iii) changes in soil N stock are rarely considered. Three indicators were recently developed at the farming system scale to overcome NUE limitations. System N efficiency (SyNE) expresses N in intended outputs as a function of all major N inputs and losses. Relative N efficiency (RNE) expresses N efficiency relatively to its potential given the nature of productions. System N balance (SyNB) expresses N losses from cradle to the gate of the farm. All three indicators include N losses due to the production and transport of inputs and soil N stock variations. The current study tested these indicators at the national scale to provide a better understanding of N management in 27 European countries. The study demonstrates the feasibility and utility of calculating these indicators at the national scale. The mean NUE of European countries is 0.35, while their mean SyNE is 0.23, highlighting the importance of considering soil N loss in efficiency indicators. Average SyNB is 113 kgN ha−1 AA, but varies from 31 to 432 kgN ha−1 AA, showing the large margin of progress of some countries regarding N losses. Mean RNE is 0.43, which means that European countries could maintain their production with much less N inputs. The systems approach enables relevant comparisons among countries with different production methods and intensities. Combining SyNE and SyNB provides complementary information about the agricultural use of N resources and the resulting environmental pressure. RNE assesses the progress margin of each country based on its production and enriches the efficiency analysis by considering the nature of agricultural products. These indicators are promising tools to study, compare and improve the N efficiency of territories or countries.  相似文献   

9.
王梦媛  高小叶  侯扶江 《生态学报》2019,39(5):1758-1771
通渭-渭源-夏河样带位于黄土高原向青藏高原过渡的生态区,是我国典型农牧交错带。长期以来,不合理的农业生产结构带来生态、经济等一系列问题,制约了该地区草地农业的持续发展。为此,从能值角度分析区域农业生产结构,可为农(牧)户决策提供理论依据,为优化区域农业生产结构提供科学依据。收集研究区农户作物和家畜生产的投入-产出数据,用能值方法分析农户生产系统结构特征、农户生产决策行为及生产系统耦合作用,用结构方程模型(SEM)分析农户生产系统能量的组分间流动。研究发现,随海拔增高,农户作物生产活动减少,作物总产出能值递减;尽管作物生产主要投入和产出要素相同,但同一作物不同地点的同一要素投入、产出能值和能值收益率均存在显著差异(P0.05);同一地点不同作物的同一要素投入、产出能值和能值收益率均差异显著(P0.05);作物生产投入要素中,有机肥能值在通渭和渭源均有较高贡献;作物投入和产出能值的农户生产决策阈值自东向西递减,在能值投入初始增加时,夏河农户作物生产规模扩增最为迅速。家畜养殖规模、能值投入和产出自东向西递增;通渭和渭源,小麦秸秆和苜蓿作为中间投入,能值贡献率达到80%;夏河家畜生产投入要素中,补饲粮食能值贡献率高达90%;家畜投入和产出能值的农户生产决策阈值点自东向西递增;能值收益率随耦合度的增加呈指数上升,通渭和渭源能值收益率的增加速度,随耦合度的增加趋于缓慢,而夏河能值收益率增速随耦合度的增加而上升。调整作物生产内部粮、经、饲产品比例结构,加强作物生产与家畜生产耦合作用,优化天然草地利用方式,实现生态效益最大化;阈值点调控农户生产决策行为,实现该区域农业生产结构优化。  相似文献   

10.
The populations of farmland birds in Europe declined markedly during the last quarter of the 20th century, representing a severe threat to biodiversity. Here, we assess whether declines in the populations and ranges of farmland birds across Europe reflect differences in agricultural intensity, which arise largely through differences in political history. Population and range changes were modelled in terms of a number of indices of agricultural intensity. Population declines and range contractions were significantly greater in countries with more intensive agriculture, and significantly higher in the European Union (EU) than in former communist countries. Cereal yield alone explained over 30% of the variation in population trends. The results suggest that recent trends in agriculture have had deleterious and measurable effects on bird populations on a continental scale. We predict that the introduction of EU agricultural policies into former communist countries hoping to accede to the EU in the near future will result in significant declines in the important bird populations there.  相似文献   

11.
Adaptability is defined as the ability of a crop (or variety) to respond positively to changes in agricultural conditions. The trait is genetically controlled and provides an ability to exploit environmental attributes, both natural and agronomic. Values of relative adaptability can be determined by the regression of the yield of the tested crop over the average yield of compared crops from several environments. We evaluated relative adaptability of 12 staple crops in 12 European countries and compared the yield data over a 43-year period from 1961 to 2003. An additional set of average yield data was also available for the 15 European Union (EU15) member countries. A wider range of 26 crop species was investigated that allowed comparisons between Europe and the USA between 1961 and 2003. Adaptability was closely related to the annual yield increases of the crops studied (r 2=0.999 both in the EU15 and the USA). However, the adaptability of certain crops differed between the two regions. Pulse, maize, millet, wheat and sorghum showed the highest adaptability in the EU15 region, whereas strawberry, pear, tomato, walnut and maize were highest in the USA. The lowest adaptability was found for walnut, pear, apple, cauliflower and hop in the EU15 and for mustard, hop, sugar beet, millet and oat in the USA. In European countries, crops with similar biology, environment and agronomical practices (like the amount of fertilizers and pesticides applied) tended to have similar adaptability values. The data indicate that high adaptability is an important prerequisite for continued yield gains in the best environments.  相似文献   

12.
Land-cover changes in the Choptank basin were estimated for 1665–1820 by using historical socioeconomic data and crop-rotation models. Socioeconomic data (human population, output per laborer, and crop yields) were obtained from the literature, whereas crop-rotation models, based on historical records, represented how agriculture was practiced. Model parameters and output were validated with export records, census data, and other historical records, and model errors were estimated to be approximately 5%. This approach indicated a sigmoidal pattern for conversion of primary forest to agricultural land by 1800. The initial time period, 1665–1720, was characterized by low-intensity tobacco and corn cultivation. Due to long fallows, the models indicated that there was little land in crops (approximately 5% of the region), but larger areas of secondary forest occurred on former cropland (approximately 15%). Although primary forest decreased, the initial result in the first 55 years was a low net rate of deforestation and occupation by low-intensity farms. However, after 1720, cropland expanded rapidly due to the use of wheat as a cash crop. From 1720 to 1775, primary and secondary forest rapidly disappeared, increasing agricultural land to 60% of the region. By 1800, approximately 80% was estimated to be converted to agriculture, and little primary forest remained. After 1800, the land needed for crops decreased due to improved management practices and crop yields, and some secondary forest on formerly cleared agricultural sites may have reappeared. We estimate that less than 150 years of European colonization resulted in virtually complete agriculturalization of a primarily forested landscape.  相似文献   

13.
Declines in insect pollinators across Europe have raised concerns about the supply of pollination services to agriculture. Simultaneously, EU agricultural and biofuel policies have encouraged substantial growth in the cultivated area of insect pollinated crops across the continent. Using data from 41 European countries, this study demonstrates that the recommended number of honeybees required to provide crop pollination across Europe has risen 4.9 times as fast as honeybee stocks between 2005 and 2010. Consequently, honeybee stocks were insufficient to supply >90% of demands in 22 countries studied. These findings raise concerns about the capacity of many countries to cope with major losses of wild pollinators and highlight numerous critical gaps in current understanding of pollination service supplies and demands, pointing to a pressing need for further research into this issue.  相似文献   

14.
中国土壤和植物养分管理现状与改进策略   总被引:99,自引:0,他引:99  
针对当前我国农业生产面临增肥不增产、土壤养分过量累积、化肥施用过量和养分利用效率下降等重大问题,本文综述了中国土壤养分与植物营养状况的历史演变和研究进展,提出中国植物营养科学研究应在跟踪国际科学前沿的同时,紧密结合中国农业生产实际,通过大幅度提高养分效率和作物产量为农业可持续发展做出应有的贡献。  相似文献   

15.
Most anthropogenic activities impacted on water quality and quantity, and further impacted on ecosystem services (ESs) in watershed are related to land use and climate changes those may cause losses of ecosystem functions. Effective information regarding ESs and their optimal priority conservation planning responded to land use and climate changes provide useful support for diverse stakeholders in ESs planning, management and policies. This study integrated the approach of spatially explicit ESs (water yield, inorganic nutrient, organic nutrient and sediment retentions) by using hydrology and material flow model (Soil and Water Assessment Tools, SWAT model) into systematic conservation of hydrological ESs according to land use and climate changes in Teshio watershed located in the north of Hokkaido, Japan. We investigated the spatial patterns and the hotspots of ESs changes to determine the spatial pattern of changes in systematic conservation optimal area of ES protection in terms of ESs protection targets. Under the land use and climate change scenarios, the forest land use significantly affected on the water yield, sediment, organic-Nitrogen (N) and organic-Phosphorous (P) retentions. The agricultural land (paddy and farmland fields) impacted on the inorganic-N and inorganic-P retentions. We applied the systematic conservation model (MARXAN model) to optimize the area for management of hydrological ESs satisfied the protection targets (30% and 50% of potential maximum ESs values among all scenarios) in all and individual ecosystem services, respectively. The simulated results indicated that the areas of spatial optimal ESs protection for all hydrological ESs were totally different from those for individual ESs. For bundles of ESs, the optimal priority conservation areas concentrated in southwest, north, and southeast of this watershed, which are related to land use, topography and climate driving factors. These places could guarantee ESs sustainability from both environmental protection and agricultural development standpoints. The priority conservation area turned more compact under climate change because the increased precipitation and temperature increased ESs amount. For individual ESs, the optimal priority conservation areas of water yield, sediment retention and organic nutrient retention were traded off against those of inorganic nutrient retention (lower Jaccard's indexes and negative correlations of selection times). Especially, the negative correlation of selection times increased as the conservation target increased from 30% to 50%. The proposed approach provided useful information for assessing the responses of ESs and systematic conservation optimal planning to the land use and climate changes. The systematic conservation optimal areas of hydrological ESs provided an effective trade-off tool between environmental protection (sediment and organic nutrient retentions) and economic development (water yield and inorganic nutrient retention).  相似文献   

16.
中国土壤和植物养分管理现状与改进策略   总被引:17,自引:0,他引:17  
针对当前我国农业生产面临增肥不增产、土壤养分过量累积、化肥施用过量和养分利用效率下降等重大问题, 本文综述了中国土壤养分与植物营养状况的历史演变和研究进展, 提出中国植物营养科学研究应在跟踪国际科学前沿的同时, 紧密结合中国农业生产实际, 通过大幅度提高养分效率和作物产量为农业可持续发展做出应有的贡献。  相似文献   

17.
Land use contributes to environmental change, but is also influenced by such changes. Climate and atmospheric carbon dioxide (CO2) levels’ changes alter agricultural crop productivity, plant water requirements and irrigation water availability. The global food system needs to respond and adapt to these changes, for example, by altering agricultural practices, including the crop types or intensity of management, or shifting cultivated areas within and between countries. As impacts and associated adaptation responses are spatially specific, understanding the land use adaptation to environmental changes requires crop productivity representations that capture spatial variations. The impact of variation in management practices, including fertiliser and irrigation rates, also needs to be considered. To date, models of global land use have selected agricultural expansion or intensification levels using relatively aggregate spatial representations, typically at a regional level, that are not able to characterise the details of these spatially differentiated responses. Here, we show results from a novel global modelling approach using more detailed biophysically derived yield responses to inputs with greater spatial specificity than previously possible. The approach couples a dynamic global vegetative model (LPJ‐GUESS) with a new land use and food system model (PLUMv2), with results benchmarked against historical land use change from 1970. Land use outcomes to 2100 were explored, suggesting that increased intensity of climate forcing reduces the inputs required for food production, due to the fertilisation and enhanced water use efficiency effects of elevated atmospheric CO2 concentrations, but requiring substantial shifts in the global and local patterns of production. The results suggest that adaptation in the global agriculture and food system has substantial capacity to diminish the negative impacts and gain greater benefits from positive outcomes of climate change. Consequently, agricultural expansion and intensification may be lower than found in previous studies where spatial details and processes consideration were more constrained.  相似文献   

18.
农业活动对生物多样性的影响   总被引:43,自引:3,他引:40  
农业生产活动如土地的农业利用、耕作、作物间套种植方式、放牧、农药化肥的使用以及农业动植物遗传改良(包括外来种引入)等是农业生产力提高的重要途径,同时也是影响生物多样性的重要因素之一。土地的不合理开发利用易导致生境破碎、生物多样性下降;大规模的机械耕作导致土壤动植物区系的变化,甚至某些物种的消失;农药(除草剂、杀虫剂等)的高度使用使非靶标动植物受到伤害;品种改良、外来种的引入以及远缘外源遗传物质的利用(如远缘杂交和DNA导入分子育种)在丰富了遗传多样性的同时导致农作物类型和品种的简单化、一些古老的地方种和农家种等传统资源丢失等;而一些合理的农业措施(间套作、实行有机农场等)将有利于生物多样性的保持。农业活动注重的是农业生产力的提高而往往忽视其对农业系统中野生动植物(包括有害和无害)的影响以及野生动植物在维持系统稳定和平衡的作用。本文论述农业活动对生物多样性的影响以及生物多样性保护对提高农业生产力的作用,启示人们采取合理的农业活动方式,合理管理有害生物,减少农业活动对生物多样性的负面影响。  相似文献   

19.
Under changing climate and burgeoning food production demands, climate-smart agriculture (CSA) practices are the need of the hour. Physically-based crop models have been designed, which require large sets of input variables, besides being timeworn, tedious, and not user-friendly in the current situation. There is a rapid advancement in the modeling approaches in agricultural practices. But, still, there is a shortage of comprehensive information related to the recent technological advancement in the modeling applications toward CSA and its prospects. The paper reviews, critically assess, and discusses the present state-of-art modeling technologies related to the CSA. Special emphasis is placed on highlighting the current research trends in the different crop simulation models and their CSA applications. The assessment and analysis of the combined implications of crop simulation and hydrological models form another vital area of our review. Subsequently, the suitability and future scope of AI in crop simulation models is thoroughly assessed. Finally, the ways to address future challenges for CSA through the models and AI-based approaches are evaluated. We have selected and critically reviewed the literature to deliberate on the various aspects of modeling and their impact on CSA. Overall, we attempted to distinctly bring out the different latest and advanced technologies and their potential roles in modeling exercises towards CSA. The current review also collates and presents new and innovative modeling approaches toward CSA with techno-feasible solutions. The review involves the simulation-optimization framework for coupling hydrological and climate models with crop models that presently have the utmost importance for the CSA. Concurrently it also highlights the overarching significance of different models and suggests refined solutions that enable better crop and environment estimation, field management, and decision-making.  相似文献   

20.
The aim of this paper is to identify the habitat types listed in the Habitats Directive Annex I that require low-intensity agricultural management for their existence. We assessed the link between the Annex I habitat types and agricultural practices in order to identify habitat types that depend on the continuation of agricultural practices or whose existence is prolonged or spatially enlarged via blocking or reducing the secondary succession by agricultural activities. 63 habitat types that depend on or which can profit from agricultural activities—mainly grazing and mowing—were identified. They are classified into 2 groups: (1) habitats fully dependent on the continuation of agricultural management; (2) habitats partly dependent on the continuation of agricultural management. This paper also briefly discusses habitat types for which either doubts remain on their dependence on agricultural management, or the relation to extensive farming practices exists only in part of their area of distribution in Europe or under certain site conditions, respectively. Assessments of the conservation status of habitats of European Importance by 25 EU Member States in 2007 showed that habitats identified by us as depending on agricultural practices had a worse status than non-agricultural habitats.  相似文献   

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