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1.
畜牧业“碳排放”到“碳足迹”核算方法的研究进展   总被引:1,自引:0,他引:1  
全球变暖趋势日益加剧,不仅影响农业可持续发展,而且威胁到人类生存。畜牧业碳排放因其在农业碳排放中乃至全球碳排放中占比较大而日益备受关注。准确核算畜牧业碳排放是制定切实可行的碳减排政策的前提,也为我国在气候变化下承担共同但有差别的减排责任提供话语权。本文基于研究范式的演进,对畜牧业碳排放到碳足迹核算方法的研究发展进行了系统梳理,研究表明,在学者的不断研究与质疑下,畜牧业碳排放到碳足迹的核算方法经历了从OECD核算法、IPCC系数法到生命周期法与投入-产出法的演变与完善,学术界认为区域异质性、养殖规模与管理方式均影响碳足迹;散养比规模化养殖产生更多的碳排放,舍饲比户外放牧排放更多的碳。畜牧业碳足迹核算能够更加全面地反映畜牧业全生命周期的碳排放情况,但由于研究假设、研究方法及研究样本等差异导致不同区域、不同畜产品的碳排放核算结果存在不确定性。运用生命周期法和投入-产出法对欧盟成员国畜牧业碳排放的核算结果基本一致,但运用IPCC系数法和全生命周期法对中国畜牧业碳排放核算中,牛、猪和羊的碳排放量排序结果不尽一致。鉴于核算结果的差异性,本研究对不同核算方法的起源、最早采用时间、特点、局限性等方面进行了归纳总结,并建议后续研究探讨基于生命周期评价的畜牧业碳足迹研究边界的延伸性,标准化畜牧业碳排放或碳足迹核算,避免学者重复核算畜牧业碳排放,以便深入展开畜牧业碳排放其他方面的研究。  相似文献   

2.
碳市场碎片化状态使各国碳排放因减排力度差异而消长,不仅造成碳泄漏风险,同时对减排国家经济特别是排放密集产业的国际竞争力产生负面冲击。本文建立多区域多部门CGE模型,设计4种边境碳调节政策,模拟分析其对我国的福利、碳泄漏和出口型排放密集产业(EITE)竞争力产生的政策效应。研究显示,我国制定边境碳调节政策,既要考虑碳关税也要考虑出口返还,前者有利于改善我国的福利水平,后者可以收到抑制碳泄漏和保持EITE产业国际竞争力的效果,因而有必要把边境碳调节政策纳入我国碳市场制度设计。无论从产出还是贸易来看,我国EITE产业中的非金属矿、有色金属、钢铁产业在边境碳调节政策影响下,面临来自日本和亚洲其他国家的竞争压力,双方的碳泄漏和产业竞争力呈现此消彼长的动态变化。在我国碳市场建设过程中,边境碳调节政策与拍卖相结合,有利于在实现碳减排目标和维护产业竞争力之间实现平衡。  相似文献   

3.
The hybrid policy is a flexible policy tool that combines features of carbon trading and carbon taxation.Its economic and environmental effects under China's background are still not studied in detail.Given the exogenous carbon reduction targets,carbon prices,and carbon tax-rates,by computable general equilibrium modeling methods and factor decomposition methods,this article investigates direct and cascaded effects of the hybrid policy on economic growth,energy utilization,and carbon emission on the national level and the sector level,with China's national input-output data-set.Stepwisely,policy scenarios with irrational estimated results are selectively excluded based on comprehensive evaluation among economic,carbon reduction and other policy targets.As a result,against national economic conditions in 2007,the hybrid policy,with a carbon reduction target of -10%,a carbon tax-rate of around $10,and a ceiling carbon price of $40,is highly recommended,because of its significant lower economic loss,lower energy utilization cost,and practical robustness against fluctuation of energy market and carbon market.Furthermore,by decomposition analysis,carbon reduction-related costs are decomposed into a direct part that includes carbon allowance price and carbon tax,and an indirect part as the energy price incremental induced by direct carbon costs.Gross carbon reduction may be decomposed into three parts such as energy intensity,economic scale,and technical progress.And,carbon taxation is the main policy tool that stimulates to improve the energy efficiency.  相似文献   

4.
中国已经在7个省市进行了碳排放权交易市场的试点,并拟于2017年建立全国碳排放权交易市场。随着碳市场政策的逐步完善,碳排放将成为企业的总量控制目标之一。在全国碳市场即将建立的背景下,研究企业对于全国碳市场政策的预期,分析企业的响应规律,估算企业对于碳信用的支付意愿,对于保障全国碳市场的顺利建立和有效运行具有重要的意义。基于此,本研究利用多边界离散选择的方式,调查了全国范围内29个省市的555家企业,对于由于全国碳市场建立而导致的能源价格提高的接受程度,并利用多元线性回归模型分析影响企业接受程度的因素,最后估算企业对于碳市场中碳信用的支付意愿。结果显示:(1)企业可接受的能源价格提高比例的平均值为8.3%,其中碳试点企业可接受的提高比例最高,达到10.2%,非碳试点企业可接受的提高比例最低,为7.5%;(2)对企业接受程度的影响因素分析显示,企业的能源价格压力,以及企业对于全国碳市场到来的时间预期与接受程度显著负相关;企业对于碳减排技术的了解程度,以及企业对于全国碳市场控制程度的预期与接受程度显著正相关;(3)对于全国碳市场中的碳信用,企业平均愿意支付的价格为79.6元/t CO_2,其中碳试点企业的支付意愿最高,为95.9元/t CO_2,非碳试点企业的支付意愿最低,为72.6元/t CO_2。据此,为保障全国碳排放权交易市场的顺利建立,实现对企业碳排放的有效控制,政府应该注重降低企业的用能成本,引导与支持企业进行技术创新与升级,提高企业对于碳市场政策的认识和了解,并充分考虑不同地区的差异和不同企业的支付能力差别,合理设定碳价。  相似文献   

5.
碳减排是减缓气候变暖的必由之路,国际社会正在积极推动全球碳减排。我国已向国际社会承诺了碳减排目标,并正在大力开展相关政策的研究和制定。碳税和碳交易是多年来各国激励碳减排最主要的两大机制。这两种机制各有优缺点,它们适当的混合机制可扬长避短,创造出更优越的机制。我们认为,碳税和碳交易机制之间最大的差别在于碳税机制有较低的制度成本(包括建立者一机制所需要的人力物力的投入,以及监管成本等),在操作性上更简便;而在对市场条件和信息的变化上没有碳交易机制的灵活性强,但从另一方面,这种灵活性也恰恰是风险产生的根源之一,它增加了企业在碳排放决策方面的风险和难度;此外,碳税相对于碳交易是间接的碳减排激励机制,碳交易机制的减排效果更直接。基于这些观察,我们设计出一种混合碳减排机制,它是碳税和碳交易机制的有机结合。该混合机制包含两个部分:首先是累进制碳税制度,小企业只缴纳碳税;其次,碳交易制度,建立碳交易市场并对于大企业确定初始碳排放权,对于大企业的超排,将按照高起点的碳税税率加以惩罚。这一混合机制,既考虑了不同企业之间在碳排放权上的公平性,又考虑了机制的效率,并在保障机制效率的条件下尽可能降低企业在碳排放决策上的风险。这些正是这一混合机制的优越性所在。我们还探讨了这一混合机制在我国实施的可行性,并提出了在具体实施过程中所应注意的若干重要事项,并给出了相关的政策建议。本文的探讨可以为政府碳排放政策制定部门提供参考。  相似文献   

6.
A necessary way to mitigate global warming is carbon reduction, which the international community is now actively promoting. China has committed a target goal for carbon reduction to the international society, and has devoted a great effort toward researching the impact of related policies. Carbon taxation and carbon trading are the two main mechanisms to advocate carbon abatement, which many countries have been using. Each of these two mechanisms possesses advantages and disadvantages, and an appropriate combination of them can make best use of their advantages while bypassing their disadvantages, creating a superior mechanism. In our opinion, the main differences between these two mechanisms are that carbon taxation has a lower institution cost (consisting of the related infrastructural investment and the regulation cost, etc), and is easier to operate, but lacks the flexibility in response to variations of market conditions. However, this flexibility is just the origin of risk, which increases the difficulty for firms in their decision of carbon abatement and is an indirect way to incentivize carbon abatement, compared to carbon trading, which has a more direct effect in carbon reduction. Based on the above observation, we present a hybrid mechanism of carbon abatement, which is an organized combination of carbon taxation and carbon trading. It consists of two parts: first, the carbon taxation, which has a progressive tax rate, second, the carbon trading. Small firms will only pay the carbon tax, while large firms, will first need to get the initial carbon emission quotas by some way, and then trade it in the carbon market if necessary. For firms with extra emissions, they will receive a punishment according to a high carbon tax rate. This hybrid policy considers the equity between different firms in carbon emission rights as well as the efficiency of the mechanism while decreasing the risk level for firms in the carbon emission decision, making it superior to the two previous policies. We also analyze the feasibility of this hybrid policy in China, address some important issues in the implementation of this hybrid policy in China and present the relevant suggestions. The discussion in this paper can serve as a reference to the government in the decision of carbon policies.  相似文献   

7.
This paper constructs a 4-lier computable general equilibrium model which includes such modules as modeling carbon emission constraints and carbon trading(CT),and incorporates the cost of carbon emissions into constant elasticity of substitute production function.Under scenario settings under different carbon abatement targets,based on 2007 national social accounting matrix and related statistical data about energy consumption and carbon emission,effects on economic outputs,energy consumption,and carbon abatement are estimated and analyzed at both macro and sector level.By calculating selected novel indicators that compromise between macroeconomic opportunity cost and achievable carbon abatement,reasonable carbon price intervals are given for enhancing the robustness and liquidity of carbon market.Further,by decomposition and share-weighted methods,expected carbon abatement and energy price are measured and analyzed in details.Some results are meaningful for fundamental design of the future carbon market.Given constant energy utilization and carbon abatement technologies at the macro level,the higher the carbon price the more actual carbon abatement;the more gross domestic product loss,the less energy consumption.Accwding to the overall situation estimated for 2007 in China,the advice given is to introduce a carbon abatement target rate(R_c)of-10%,which is helpful to make carbon market stable against unexpected carbon price shocks between[6.9,35]/tC with less economic loss.According to Kaya decomposition,after introduction of carbon pricing,carbon abatement is mainly contributed by the effects of energy intensity(EI)and technical progress.Further,CT may help reduce energy consumption and induce transformation to a low-carbon energy structure.At the sector level,the introduction of CT could induce economic recession in all sectors,especially energy.However,the overall economic structure remains unchanged to some extent.CT will help reduce energy consumption in all sectors,especially energy.Overall utilization costs of the energy composite can be divided in two,market price and carbonrelated costs.Carbon-related costs mainly contribute to variation in the utilization cos of the energy composite;carbon pricing may help non-energy sectors achieve sufficient carbon abatement by pushing up energy utilization cost.However,despite achievable carbon abatement by the energy sector being relatively high,induced by carbon pricing,there is still significant potential for other incentive policies to stimulate further abatement,such as energy resources taxation and transportation fuel taxation,especially in the sectors of coal and transportation.Finally,some advice is proposed in regard to policy decisions and further research.  相似文献   

8.
碳标识属于一种环境标志,中国碳标识标注内容的规范需要在参考国际环境标准体系包含的Ⅰ型、Ⅱ型、Ⅲ型标志的基础上作出改进。基于立法学分析,碳标识标注内容的规范原则包括信息量化原则、描述和评价结合原则、包容原则。碳标识内容的制度设计思路包括:①采取先单行型、后分散型的立法模式,先单行规定碳标识内容的一般性规则,再分散规定碳标识内容在具体应用的行业领域中的规则;②基于信息量化原则借鉴Ⅲ型环境标志所涉标准体系,其中重点借鉴碳标识标准ISO 14067;③基于描述与评价结合原则借鉴并改进食品标签营养参考值内容之规范模式,建立碳排放参考值规范及与之配套的消费领域分类规范,并通过标准文件"推荐性/强制性"的切换契合碳标识内容规范在不同消费领域中规制强度需求不同的特点;④提倡基于Ⅰ型、Ⅱ型环境标志的碳标识应用,合理鼓励中国碳标识认证进行创新与竞争。由此,对碳标识内容的规范可通过进一步整合,完善中国绿色产品认证体系建设。同时,为确保碳标识内容规范的可操作性与社会效益,碳标识内容的规范化仍需要多学科的参与。  相似文献   

9.
The removal and transformation of natural organic matter were monitored in the different stages of the drinking water treatment train. Several methods to measure the quantity and quality of organic matter were used. The full-scale treatment sequence consisted of coagulation, flocculation, clarification by flotation, disinfection with chlorine dioxide, activated carbon filtration and post-chlorination. High-performance size-exclusion chromatography separation was used to determine the changes in the humic substances content during the purification process; in addition, a UV absorbance at wavelength 254 nm and total organic carbon amount were measured. A special aim was to study the performance and the capacity of the activated carbon filtration in the natural organic matter removal. Four of the activated carbon filters were monitored over the period of 1 year. Depending on the regeneration of the activated carbon filters, filtration was effective to a degree but did not significantly remove the smallest molar mass organic matter fraction. Activated carbon filtration was most effective in the removal of intermediate molar mass compounds (range 1,000-4,000 g/mol). Regeneration of the carbon improved the removal capacity considerably, but efficiency was returned to a normal level after few months.  相似文献   

10.
碳交易是为促进全球温室气体减排、减少全球二氧化碳排放所采用的市场机制。广东省作为中国七个碳交易试点之一,将碳交易的核心理念应用于促进居民生活减碳,首次提出碳普惠制创新。碳普惠制旨在将公众的低碳行为量化并予以激励,以此促进低碳生活实践,降低生活领域碳排放。本文以公共自行车交通系统为研究对象,借鉴CCER方法学,对公共自行车项目的个人减排量核算方法进行了设计,并参考文献统计数据举例说明个人减排量核算公式。公共自行车项目个人减排量核算的方法学设计中,减碳系数的计算考虑自行车可代替的所有出行方式,且在不同出行方式比例的统计中考虑出行距离的影响,设置随出行距离变化的减排系数,在减排量的计算中有效突出个人的减排贡献量。依据本方法学计算得到了城市公共自行车项目个人减排系数曲线及减排量核算公式。最后从数据收集的角度出发,提出相应的改进建议以提高方法学的科学性及适用性。本方法学能客观评估城市公共自行车出行的个人碳减排量,为碳普惠制的实施提供量化方法学参考,同时填补了目前个人碳减排核算研究领域的空白。  相似文献   

11.
Currently, the global carbon trading systems are fragmented and belong to different governments or are under the jurisdiction of different regions, resulting in a series of new problems, such as how to link dispersed trading systems, how to compare the emission reduction of various markets and other issues. Since the development of the international carbon market is relatively immature with uncertain life expectancy and volatility during its short history, and there is a lack of quantitative data on the long-term record, the market could provide few risk management tools. Meanwhile, with the launches of China’s regional carbon trading pilots in seven provinces since 2013 and combined with the national voluntary emission trading system, carbon trading will become an important mechanism for China in achieving its emission reduction target. In the first stage, the carbon finance market is at least faced with mechanism design risks, market supply risks and compliance risks. Therefore, to secure the development of the carbon market and for public interest, relevant government departments of China should identify the risks facing the market and should make the basic principles and goals, such as ensuring effective trading and pricing mechanisms to avoid fraud and price manipulation, and balancing transparency and confidentiality of information. Consequently, the governments should develop a comprehensive carbon finance regulatory system covering regulatory legislation, regulatory institutions and their authorities, regulatory scope as well as regulatory objects.  相似文献   

12.
在产品市场和碳交易市场均为完全竞争的市场结构中,碳交易机制是一种有效的环境政策,但在现实环境下,产品市场和碳交易市场往往都是不完全竞争的。本文采用复杂适应系统仿真的方法,构建基于SWARM的碳交易市场仿真模型,建立碳排放权交易市场仿真系统,研究产品市场和碳交易市场结构对碳交易市场的运行效率的综合影响,同时为了降低产品市场垄断企业对碳交易市场运行效率的影响,本文通过增加碳交易市场配额缺口和增加参与交易的中小控排企业数量两种方式,探寻如何在产品市场不完全竞争的环境中设计合适碳交易机制。研究发现:1产品市场垄断会导致碳交易市场流动性不稳定,出现波动聚集等现象。2在产品市场处于相同结构时,碳交易市场垄断会导致成交量和成交额减少,流动性降低。3不同市场结构对碳交易市场的价格波动没有显著影响。4产品市场的市场结构会影响碳交易市场运行的有效性,完全竞争的产品市场下,碳交易市场的收益波动符合随机游走,而垄断力会改变这一特征。5市场流动性随着碳配额缺口的扩大发生显著变化,成交量和成交额随之显著增加,在产品市场垄断的市场结构中,通过加紧配额供给,可以增加碳交易市场的流动性,改变碳交易市场低迷的交易状况。6鼓励小企业参与市场交易对碳交易市场的流动性没有产生显著影响,但会在一定程度上降低垄断企业在碳交易市场上的支配力,从而改善碳交易市场的有效性。  相似文献   

13.
The concentrations of total, inorganic and organic carbon in the surface sediment of the central part of the Venice lagoon (31-55 stations) during the month of June in 1987, 1993 and 1998 were recorded. In two stations: San Giuliano and Lido, samples were collected on a monthly basis for 1 year also in different periods. On an average, by considering the whole central lagoon, inorganic carbon (IC) and total carbon (TC) did not show significant changes. In contrast organic carbon (OC) had alternating trends showing a decrease from 1987 to 1993, due to the almost complete disappearance of huge macroalgal biomasses, and a marked increase from 1993 to 1998, because of the high sediment disturbance caused by the catching of the clam Tapes philippinarum Adams & Reeve which had colonised the sediment free of macrophytes. The carbon changes monitored in the two stations studied on a seasonal basis during different years not only confirmed such results, but also enhanced the effects of fishing activities at Lido station and those depending on the disappearance of macroalgae at S. Giuliano. Moreover, this paper underlines the importance of seagrass beds. In fact in the areas colonised by those plants the percentage of fine sediments and organic matter is on the increase, while erosive processes are contrasted.  相似文献   

14.
This contribution deals with the controversy between certain scientists on the role of terrestrial vegetation and soils in the global carbon cycle. The hypothesis of a significant net release from the vegetation, is rejected by geochemists because of the limited capacity of the ocean to take up this excess carbon dioxide. As for the man-influenced tropics, a comparison of the figures for the potential and the current phytomass, as well as plausible demographic arguments, support the assertion put forward by ecologists that the carbon budget of this zone cannot be balanced. The tropics lose about 1.7-3.9 × 1015 g/yr of carbon to the atmosphere; however, for several reasons, 0.5-2.8 × 1015 g/yr may be returned to land ecosystem, mostly in other climatic zones. Thus, a balance is achieved on combining low estimates for the losses with high estimates for the gains. From an ecological perspective, this solution is not a very probable one; nevertheless, it cannot conclusively be eliminated.  相似文献   

15.
Climate change is one of the focuses to mitigate greenhouse effect and reduce carbon dioxide emissions.First,the paper summarizes on the carbon dioxide emission factors and methods suitable to the situation in China.Second,it analyzes the primary energy-related carbon dioxide emissions during the period between 1995 and 2005 from different fossil fuels and different zones.The trend of primary energy-related carbon dioxide emissions from 1995 to 2005 is"first decreasing and later increasing."Seven regions-Liaoning,Shanxi,Hebei,Shandong,Henan,and Jiangsu-and most of the provinces(cities or regions)were found to have similar trends regarding total carbon dioxide emissions in China.The annual carbon dioxide emissions and the growth ratio of these seven regions are much higher compared to those of the other 24 provinces(cities or regions).Finally,this paper puts forward some suggestions to reduce carbon dioxide.  相似文献   

16.
As part of a larger study to quantify and map ecosystem services in southeast Australia, we estimated carbon stored in biomass and soils and the net ecosystem carbon exchange between the land surface and the atmosphere in the Australian Capital Region (ACR). Our aim was to understand and quantify how different human-modified landscapes provide an essential ecosystem service: the exchange and storage of carbon in the landscape. Using a remote sensing based modelling methodology, we obtained values of Net Primary Productivity (NPP), total carbon in soil and biomass and carbon turnover from meteorological and terrain inputs and vegetation attributes. We obtained a set of maps of NPP, total carbon (C) storage and C-turnover for the ACR. We superimposed a land use/cover map to assign the uptake, storage and release of carbon to different land use/cover types. Our results support the hypothesis that human-intensive land uses significantly affect the ability of terrestrial ecosystems to provide an important ecosystem service in the form of carbon storage.  相似文献   

17.
This study investigates the nature of the empirical link between an individual’s well-being and their carbon footprint. It employs a novel approach matching data from the Household, Income and Labour Dynamics in Australia survey, to household expenditure and greenhouse gas-based carbon footprints. The carbon footprints are calculated using environmental factor multipliers from the detailed and globally integrated multi-regional input–output (MRIO) tables provided by the Eora MRIO database. The results indicate that higher carbon footprints are associated with marginally lower levels of well-being. This relationship appears to be linear. Furthermore, this relationship does not differ greatly for individuals across the well-being distribution. The findings of this study both: (1) add to the body of knowledge on the link between carbon footprints and well-being; and (2) provide policy makers with evidence and strategic guidance on the well-being implications of mitigating carbon footprints.  相似文献   

18.
石化行业作为中国八大典型高碳排放产业之一,也是碳市场参与的重要行业.在国家2020年碳排放强度目标的约束下,客观评价其行业减碳的压力,对于政府部门科学制定各个行业碳排放配额的分配方案具有重要支撑作用.同时,亦对于通过低碳转型升级实现行业的可持续发展和支撑国家的工业减排目标具有理论和现实意义.本文针对石化行业9个子部门,结合我国经济发展的总体背景和趋势以及石化行业的相关数据,以2010年为基准情景,在2020年国家碳排放强度分别下降45%和50%的减排约束目标下,构建了一个动态CGE模型——PCCGE,借助GAMS软件模拟分析,预测了到2020年国家和石化行业经济总量、能源消费结构和碳排放量及碳强度等的变化趋势.研究结果表明,相比基准情景,在45%、50%的碳强度减排目标下,国家和石化行业的经济增长、能源消费结构和碳排放强度等指标分别受到一定程度影响,其中,50%的减排目标对国家整体经济增速影响更为明显;对煤炭、石油这两种高碳能源的需求产生了较显著的约束效应;相比国家45%-50%的低碳发展目标,石化行业减碳承受压力达到60.63%至64.78%,面临着艰巨的减排任务与挑战.最后,文章结合低碳市场化背景提出了如下建议:科学预测典型离碳行业的减碳潜力,谨慎应对石化等行业企业参与碳市场交易过程中碳配额指标的制定与分配;充分利用技术创新和能源结构调整等战略,提高可再生能源的使用规模,促进能源消耗结构的优化和调整;构建石化行业节能低碳技术产学研协同创新体系,解决共性节能技术瓶颈;实施石化行业企业低碳发展战略,建设完善碳排放管理体系是行业节能减碳的重要手段.  相似文献   

19.
总量控制下的碳市场在减少温室气体排放的同时,会增加企业的碳排放成本,进而可能降低企业的贸易竞争力。本文选择全国碳市场覆盖的6个能源密集型和贸易暴露型行业,以行业贸易竞争力指数、行业出口值和出口竞争力指数作为贸易竞争力的衡量指标,研究了碳价格对它们贸易竞争力的影响。由于缺乏全国碳价格数据,本文选用能源成本作为碳价格的代理变量,先研究能源成本对覆盖行业贸易竞争力的影响,通过碳价格向能源成本的映射关系,再研究碳价格对覆盖行业贸易竞争力的影响。首先,本文设定(对数)线性模型,研究了行业能源成本对行业贸易竞争力的影响。结果显示,行业能源成本每提升100元,行业贸易竞争力指数约下降0.0136;行业能源成本每提升100%,行业出口值和行业出口竞争力指数分别下降约22.97%和12.26%。然后,本文研究了行业能源消费和二氧化碳排放之间的关系,建立碳价格向行业能源成本的映射。由于短期内行业能源消费结构比较稳定,每消费1单位能源,行业排放二氧化碳的量就相对固定,但又因行业间的能源结构存在差异,相同的碳价格映射到各行业的能源成本也就不同。之后,本文构建存在全国碳价格的反事实情景,通过映射关系研究了不同水平碳价格对覆盖行业贸易竞争力的边际影响和累积影响。结果显示,碳价格对覆盖行业的贸易竞争力的边际影响递减。由于行业能源成本、映射系数及出口规模的不同,碳价格对覆盖行业出口值的影响规模存在一定的差异。最后,本文根据研究结果提出相关政策建议。  相似文献   

20.
The dynamics of carbon pools in the live phytomass, necromass, and soil reservoirs have been analyzed in fallow arable lands of Novgorod oblast. The results show that the amounts of above- and belowground necromass increase with the age of fallows, while the dynamics of live phytomass have no distinct trend. Comparisons with archival data show that the stocks of soil organic carbon in the studied ecosystems have decreased by 1.39 t C/ha since 1983, which is equivalent to an annual loss of 0.03 t C/ha. The main factors accounting for changes in the carbon stocks of fallow soils are the initial organic carbon contents in topsoil, the intensity of agromeliorative measures taken during the period of agricultural land use, and carbon contents in soils of meadow communities typical for a given region (zone).  相似文献   

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