CO_2浓度升高对植物光合作用的影响

近年来大气中CO_2浓度急剧增加。CO_2作为植物光合作用的底物,其浓度的升高必然对植物生长产生影响。本文从植物叶片形态结构、光合色素含量和光合速率三个方面,阐述了大气CO_2浓度升高对植物光合作用产生的影响。     

大气CO2浓度升高与植物生态系统反应

植物生态系统是人类赖以生存与持续发展的生命支持系统，自工业革命以来，大气中CO2的浓度持续增加，导致了温度等气候因子的变化，对植物生态系统的维持与发展造成了巨大的影响，引起了人们的广泛关注。总结了CO2升高对植物生态系统的影响以及植物生态系统反馈作用，并分析了研究的局限性及其需要加强的一些研究领域。     

大气CO2浓度升高与植物生态系统反应

植物生态系统是人类赖以生存与持续发展的生命支持系统,自工业革命以来,大气中CO2的浓度持续增加,导致了温度等气候因子的变化,对植物生态系统的维持与发展造成了巨大的影响,引起了人们的广泛关注。总结了CO2升高对植物生态系统的影响以及植物生态系统反馈作用,并分析了研究的局限性及其需要加强的一些研究领域。     

空气CO2浓度升高对玉米产量的影响

玉米作为我国主要的农作物,其产量直接关系到种植户的利益与国家粮食安全,因此加强对玉米增产措施的研究具备现实操作的实际意义。本文以郑单958为研究对象,通过设置自然大气(CK)和大气CO_2浓度升高(OTC)分别与水肥管理雨养不施氮、雨养施氮以及覆膜与不覆膜四种模式相结合的办法测试。在深入分析结果的基础上,对种植户种植农作物提出了具体参考建议。     

土壤呼吸对大气CO2浓度升高的响应研究进展

土壤呼吸作为陆地生态系统碳循环的重要组成部分,其微小变化会直接影响碳循环过程。目前,土壤呼吸对全球大气CO₂浓度升高响应已引起广泛关注。本文初步总结了模拟土壤呼吸对CO₂浓度升高响应的研究进展,尤其关注CO₂浓度升高对土壤呼吸组分的影响差异和微生物调控机制等。深入认识CO₂浓度升高-微生物-土壤呼吸之间的关系,有利于在未来全球变化的背景下,提高土壤碳汇功能。在此基础上,指出了当前土壤呼吸对CO₂浓度升高的响应过程中存在的问题和不足,并对未来研究提出展望。     

大气CO2浓度升高对小叶章光合色素含量和光合参数的影响

研究了CO2升高对小叶章光合色素含量及相应光合参数的影响。实地条件下测定了净光合速率(PN)对光合有效辐射(PAR)的响应曲线,根据非直角双曲线模型,推算最大净光合速率(Amax)、暗呼吸速率(Rd)以及表观量子产量(AQE)等。结果表明CO2升高增加了小叶章叶片光合色素含量,但却降低了光合参数Amax、Rd以及AQE。光合色素含量和光合参数呈现不同的变化趋势。     

CO2浓度升高对湿地生态系统 凋落物分解的影响

凋落物分解是生态系统的重要过程之一。主要由生物因子(土壤微生物、土壤动物)与非生物因子(环境因子、凋落物质量)综合控制。CO_2浓度升高一方面会改变生态系统凋落物的种类组成、凋落物产量、凋落物质量从而来影响凋落物分解过程,另一方面通过影响土壤动物和土壤微生物的群落结构以及活性来调节凋落物分解。近年来,以全球变暖和CO_2浓度升高为主的全球变化对凋落物分解的影响受到广大学者的关注,但其研究结果具有很多不确定性,并且主要集中在森林和草原生态系统。湿地面积虽然仅占地球陆地面积的4%-6%,却储存着全球20%-30%的碳。因此,未来的研究重点应该集中在CO_2升高背景下研究湿地生态系统凋落物分解的内在机制,从而为未来全球变化大环境下湿地生态系统管理做出理论参考。     

沙漠蝗虫侵袭对萨赫勒地区的农业生产造成威胁

在萨赫勒地区，沙漠蝗虫今年正在对农业生产造成严重的影响。粮农组织最新沙漠蝗虫报告补充材料报道，在遍及毛里塔尼亚、塞内加尔、马里、尼日尔的萨赫勒地区范围内，今年9月份的前半个月沙漠蝗虫继续大范围繁殖，而在布基纳法索其程度则稍低一些。跳跃性蝗虫群体正在萨赫勒地区的所有发展中国家快速扩大。     

超临界CO2法制备食用调味花椒油的工艺

采用超临界CO2萃取技术提取食用调味花椒油,采用正交实验法对超临界CO2提取花椒油的工艺进行优化,以花椒油的提取率为指标,考察萃取压力、温度、CO2流量对花椒油收率的影响。最佳工艺条件为：萃取压力30MPa、萃取温度40℃、CO2流量19—20L／h、花椒油提取率13．4％。以超临界CO2提取花椒油收率高、提取时间短,产品符合国家有关食用调味油标准。     

Allocating provincial CO2 quotas for the Chinese national carbon program

In order to improve the efficiency of climate change initiatives China launched its national carbon market in December 2017. Initial CO2 quota allocations are a matter of significant concern. How should we allocate CO₂ emissions reduction responsibilities among Chinese provinces, assuming that provinces will not or cannot trade these responsibilities among themselves? In this paper, we allocate CO₂ quota from the perspective of cost minimisation. First, we estimate the national CO₂ marginal abatement cost (MAC) function and deduce the interprovincial MAC functions. Second, we build an allocation model with nonlinear programming for cost minimisation. Finally, we obtain the allocation results under the emissions reduction target by 2030. The results are as follows. (i) The national MAC was 134.3 Yuan/t (at the constant price of 1978) in 2011, with an overall upward trend from 1990 to 2011. (ii) The interprovincial MACs differ significantly and decline gradually from east to west. Hebei has the largest emissions reduction quota, and Shandong has the largest emissions quota by 2030. (iii) Compared with other criteria of per capita, gross domestic product (GDP), grandfathering and carbon intensity, the proposed approach is the most cost‐effective in achieving the reduction target, with cost savings of 37.7, 34.5, 47.9 and 33.87 per cent, respectively.     

Non‐Parametric Modelling of CO2 Emission Quota

Dutch glasshouse firms are facing the introduction of a system of tradable CO₂ emission quotas. This paper employs a non‐parametric method for modelling tradable CO₂ emissions of Dutch glasshouse firms. The method is capable of generating shifts in CO₂ emissions across the sample of firms. Moreover, changes in volumes of outputs produced and inputs used are computed. Results show that firms using a conventional heating technology will be net purchasers of CO₂ emissions, whereas firms using more advanced heating technologies will sell part of their emission quota.     

森林碳汇:后京都时代减排的重要途径

分析指出森林碳汇较其他减排措施具有潜力大、易操作、见效快、成本低、对经济增长影响小、居民福利高的独特优越性,必将受到国家气候变化应对措施选择的青睐。同时指出,森林碳汇不但包括换取排放中的造林和再造林的碳汇项目,而且包括抵消排放中的增加的森林碳库。分析国际气候变化谈判的焦点难点,指出森林碳汇必将成为后京都时代减排的重要途径之一。     

Technical efficiency and CO2 abatement policies in the Dutch glasshouse industry

This paper develops a short-run microeconomic simulation model of the Dutch glasshouse industry in order to investigate the relation between technical efficiency and marginal abatement costs of CO₂ emission. The model is also used to determine the effects of an emission tax and systems of tradable and non-tradable quota for groups of firms with different rates of technical efficiency. The results show that marginal abatement costs are very responsive to changes in technical efficiency. Furthermore, it is found that firms with a low technical efficiency are faced with a higher profit reduction under different abatement policies than firms with a high technical efficiency.     

The Impact of FDI on CO2 Emissions in Latin America

This paper uses panel Granger causality tests to study the relationship between sector-specific foreign direct investment (FDI) and CO₂ emissions. Using a sample of 18 Latin American countries for the period 1980–2007, we find causality running from FDI in pollution-intensive industries (“the dirty sector”) to CO₂ emissions per capita. This result is robust to controlling for other factors associated with CO₂ emissions and using the ratio of CO₂ emissions to GDP. For other sectors, we find no robust evidence that FDI causes CO₂ emissions.     

Evaluating the uncertainty in estimates of the economic impacts of Bovine-Leukosis virus in U.S. dairy cows

An examination of the economic impacts of Bovine‐Leukosis virus indicated that reduced milk production, attributed to the presence of Bovine‐Leukosis virus in dairy cows, reduced consumer surplus by 2.7 ± 2.3 billion US$ (bUS$), and resulted in a total partial equilibrium loss of 720 ± 560 million US$ (mUS$) to the U.S. economy in 1996. Most of the economic surplus lost by consumers was transferred to producers, whose economic surplus increased by 2.0 ± 1.8 bUS$ as a result of reduced milk production attributed to the presence of Bovine‐Leukosis virus in dairy cattle. Uncertainty analysis showed that an estimate of the milk‐production decline per percent increase in the prevalence of Bovine‐Leukosis virus in dairy cows accounted for most of the uncertainty in the economic‐impact estimates. If Bovine‐Leukosis virus had not been present in U.S. dairy cows, then milk production would have increased by 2.0 billion ± 1.5 billion kg, the price would have fallen by 3.8 ± 3.2 cents/kg, and the value of the milk produced would have decreased by 2.1 ± 1.9 bUS$. Guidelines delineated by the International Organization for Standardization, for evaluating and expressing uncertainty in measurement, are discussed and proposed for use in the context of broad national estimates, for which the economic impacts of Bovine‐Leukosis virus serve as an example. The principal advantages of the methodology are the clarity and transparency of results, and the ability clearly to identify major uncertainty contributors.     

恢复干扰技术对盐碱化草地植被与土壤碳排放的影响

针对松嫩平原盐碱化草地生态退化现状,研究运用不同干扰程度的围栏封育、震动深松、浅翻轻耙、施肥(沼气化废弃物)和人工草地等草地植被恢复技术进行生态恢复,通过监测结果表明各种恢复技术对盐碱化草地植被恢复具有明显促进作用,植被盖度、高度和生产力大幅度提高。同时,人为扰动改善了土壤结构,植被凋落物增加,导致土壤呼吸作用加强,CO2排放通量增加,但由于植被碳固定的增加率远高于土壤CO2排放通量增加率,因此,生态恢复技术的实施增强了盐碱化草地碳"汇"功能,并且随着生态恢复技术中人为干扰强度的增加,这种增加趋势更加明显。     

Impact of foreign direct investment on greenhouse gas emissions in agriculture of developing countries

This research analyses the impact of foreign direct investment on greenhouse gas emissions in the agriculture sector of developing countries. Panel data from 63 developing countries for the period 2005 to 2014 was used to estimate a dynamic econometric model by applying a system‐generalised method of moments. The empirical results indicate a positive impact of foreign direct investment in agriculture on the carbon dioxide equivalent emission intensity in developing countries. The results provide weak support for the pollution havens hypothesis and imply the importance of coordination between foreign direct investment and environmental policies.     

黑龙江省采矿业能源消费碳排放影响因素研究

本文对黑龙江省采矿业2005年至2012年的能源消费碳排放量进行估算,并对碳排放现状进行分析。运用改进的STIRPAT模型对黑龙江省采矿业碳排放的影响因素进行分析,得出影响采矿业碳排放的影响因子,运用计量经济学软件采用面板固定效应对数据进行回归分析,得出影响因子对于碳排放量的影响系数,根据黑龙江省采矿业分行业二氧化碳排放影响因素实证分析结果,提出黑龙江省采矿业碳减排的对策与建议。