黑碳气溶胶排放量测算及空间分布研究

 基于统计学方法计算了中国大陆省域2012年黑碳气溶胶排放清单。研究表明,2012年中国大陆黑碳排放总量为188.676×10⁴ t,其中居民生活源排放量为81.800×10⁴ t,占黑碳排放总量的43.3%,位居首位。工业在生产和最终消费中排放黑碳80.914×10⁴ t,占全国排放的42.9%,工业源和居民生活源排放量占总量的86.2%,是中国黑碳最主要的排放源。交通运输和生物质燃烧放排放量分别为17.809×10⁴和6.667×10⁴ t,分别占总量的9.4%和3.5%。火电和供暖行业排放量较小,仅占到排放总量的0.8%。从能源类型看,黑碳主要来源于煤炭和生物燃料燃烧,分别占54%和31.6%。黑碳排放省域空间分布不均匀,呈东高西低的趋势,与区域经济发展情况和农村人口密度一致;从各个地区来看,山西省在全国黑碳排放量中位居首位,河北、山东、河南、内蒙古依次位列前5,这5个省份贡献了全国约37%的排放量。山西省的主要排放源来自工业,占全省排放的82.4%。山西是煤炭大省,炼焦行业发达,煤炭的大量使用造成该省较高的黑碳排放。河北、山东的排放源主要贡献也来自工业,分别占本省排放量的61.5%和57.5%,同时居民消费也占有一定比例。河南省农村人口密度较高,居民生活源黑碳排放占总量的50%,内蒙古则由工业源和生活源共同贡献,两者贡献比例各占45%左右。     

中国主要树种人工乔木林碳储量测算及固碳潜力分析

【目的】森林碳储量在陆地生态系统碳库中占主体地位,通过确定人工乔木林碳密度和植被固碳增值碳储量,预测人工乔木林碳汇潜力,为改善人工乔木林的林龄和树种结构、提高森林可持续经营水平,进而为提高人工乔木林单位面积蓄积量提供科学依据,助力我国实现增汇减排的目标。【方法】比较分析我国第8次(2009—2013)和第9次(2014—2018年)森林资源清查中各优势树种人工林的面积和蓄积量数据,采用联合国政府间气候变化专门委员会(IPCC)材积源-生物量法(volume-biomass methods)分别估算并对比我国6种主要树种人工乔木林的碳储量和碳密度,分析人工乔木林碳储量和碳密度在两次森林资源清查期间增值部分的碳贡献率,综合评价我国不同林龄结构人工乔木林的固碳功能;采用拟合的单位面积蓄积-林龄的Logistic回归生长方程,结合IPCC材积源-生物量法,预测不同龄级各优势树种的蓄积量,估算我国现有人工乔木林未来15年及至2035年的碳汇增值潜力。【结果】两次森林资源清查期间,我国主要人工乔木林总碳储量增加了498.81 Tg,年均增加量99.76 Tg。第9次资源清查结束时,6个主要树种不同林龄(组)人工乔木林的碳储量由大到小依次为过熟林(439.19 Tg)>成熟林(426.43 Tg)>近熟林(359.75 Tg)>中龄林(292.34 Tg)>幼龄林(105.15 Tg),分别占人工乔木林总碳储量的27.07%、26.28%、22.17%、18.02%和6.47%;不同龄组的碳密度从小到大依次为过熟林(59.17 Mg/hm²)<幼龄林(169.12 Mg/hm²)<成熟林(178.13 Mg/hm²)<近熟林(190.38 Mg/hm²)<中龄林(348.09 Mg/hm²)。到2035年,我国主要树种人工乔木林碳储量和平均碳密度将分别达到1 716.27 Tg和36.51 Mg/hm²,与2015年相比分别增加92.92%和93.17%。【结论】两次森林资源清算结果相比,6种主要树种人工乔木林的碳储量均有显著增加,随着林分的不断成熟,碳储量呈现出线性正向增加的趋势,而碳密度受蓄积量与面积比的影响其增幅各不相同;至2035年人工乔木林碳储量约占乔木林总碳储量的20%,可以预见中国人工乔木林碳储量有很大的增加潜力。     

云南主要森林植被碳储量及固碳潜力模拟研究

使用日本对地观测卫星(advanced land observing satellite,ALOS)2008—2011年的影像数据,解译云南现状植被分布.使用分类回归树模型(classification and regression trees,CART)预测云南主要森林植被的潜在分布区,估算云南森林植被的碳储量和固碳潜力.结果显示:云南省林地总面积是2.0×107hm2,森林覆盖率为52.49%,主要森林植被碳储量为871.14 Tg;不同森林植被碳储量及固碳潜力不同,碳储量较高的是季风常绿阔叶林、暖温性针叶林和暖热性针叶林,分别为205.42、172.72 Tg和137.78 Tg,而固碳潜力较大的是暖热性针叶林、暖温性针叶林和温凉性针叶林,分别为788.53、119.00 Tg和156.78 Tg,分别是现实碳储量的5.7倍、2.1倍和0.91倍;云南主要森林植被总固碳潜力为1 321.52 Tg,约为现实碳储量的1.52倍.总体上,云南省针叶林的固碳潜力远大于阔叶林,适当的人为干扰可提高暖热性针叶林的固碳潜力,暖热性针叶林具有较强的清洁发展机制(clean development mechanism,CDM)潜力,云南省主要森林植被在整体上是一个碳汇.     

甘肃省白银地区草地资源特征与草地生态变化

天然草地的组成类型及退化特征,对草地资源的合理利用和退化草地生态的恢复治理具有重要的生态学意义.对白银地区天然草地资源组成、草地类型结构以及退化草地植被特征进行了系统调查与分析,研究了不同退化演替时期草地植物生态型、生产力的构成变化规律.随草地退化程度的加剧,从初期到后期,高位芽植物最先消失,草地植物群落物种数和优势种密度急剧下降,群落盖度、生物量比、鲜草产量与可食草产量百分数均呈逐渐下降趋势.提出了天然草地永续利用的对策.     

天然温带典型草原N2O和CH4通量的时间变化特征

以内蒙古温带半干旱典型草原类型羊草草原土壤为主要研究对象,利用静态箱技术在野外连续多年原位观测草地N2O和CH4排放通量.通过对1995,1998,1999,2001,2002和2003年的野外观测资料的数据分析,发现温带半干旱典型草原N2O通量的日变化特征明显,草原植物的不同生长阶段对其具有显著的影响;CH4通量的日变化没有明显的规律性特征,植物生长状态对其影响不明显,但对于草地吸收CH4的日较差有显著的影响.多年观测资料显示:我国温带草地N2O通量的排放峰值在四季中均有可能出现,低值通常出现在冬季,不同实验年份,不同季节都有出现N2O吸收通量的可能性,N2O季节通量的变化形式多样,通常是春、夏季较高,冬季最低.CH4通量季节变化规律相对明显,其峰值主要出现在春季,冬季较低.在不同的季节都观测到CH4的排放通量,这同草地出现N2O的吸收通量一样不影响温带草地作为N2O源和CH4汇的功能.N2O较CH4通量的年际变化显著,两者年通量的变异系数分别是71.6%和18.7%,5个实验观测年(跨9个年度),N2O和CH4年通量的平均值分别是:(1.14±0.82)kg·hm-2·a-1和(-3.52±0.66)kg·hm-2·a-1.统计分析结果表明:只有CH4的季节通量与降雨量之间存在显著线性关系.以此估算我国温带草地N2O和CH4年排放总量分别是:以氮计0.23 Tg和以碳计-0.83Tg,分别是全球温带草地N2O排放总量的23%以及全球土壤吸收CH4总量的11%.     

不同施肥处理对高寒草地的影响

为了探究施肥对青藏高原高寒草地生态系统的影响,以色达县天然草地为对象,研究氮肥(尿素)、液体肥(农肥)对高寒草地植被特征及土壤物理性状的影响,结果表明:1)施氮肥(K2)处理下地上生物量高于其他处理组(P0.05);2)物种丰富度指数、多样性指数和禾本科植物的多样性在K2处理组下有显著的增加(P0.05);3)植被高度、盖度、土壤含水率、土壤容重及植被鲜干比无显著性差异(P 0.05).说明相较于农肥,施氮肥对高寒草地的促进作用更加显著.该结果为促进青藏高原高寒草地恢复提供了科学的理论依据.     

三角城种羊场三种植被类型生物量及土壤碳氮含量比较

以位于青海湖北岸的青海省三角城种羊场为研究区域,选取芨芨草草地、金露梅灌丛和冷地早熟禾草地为研究对象,对3个样地地上和地下生物量、土壤基本理化性质、0～30 cm土体土壤有机碳和全氮储量分别进行了比较研究。结果显示:3种不同植被类型样地相比较,地上生物量从高到低表现为:金露梅灌丛>芨芨草草地>冷地早熟禾草地,其中芨芨草草地和冷地早熟禾草地之间差异不显著(P>0.05),但都显著低于金露梅灌丛(P<0.05);0～30 cm土体总地下生物量从高到低亦表现为:金露梅灌丛>芨芨草草地>冷地早熟禾草地,其中金露梅灌丛与其他2种植被类型间差异显著(P<0.05)。所测样地土壤均呈偏碱性;土壤含水量介于13.94%～56.10%之间,3种植被类型0～30 cm土层平均土壤含水量以金露梅灌丛最高;不同植被类型下土壤容重的垂直变化规律均不相同。30 cm深度单位面积土壤有机碳和全氮储量从高到低均表现为:金露梅灌丛>芨芨草草地>冷地早熟禾草地,其值分别为12.12、7.83、5.87 kg/m2和1.11、0.93、0.62 kg/m2,金露梅灌丛与芨芨草草地、冷地早熟禾草地间差异显著(P<0.05)。     

黑河市森林火灾碳排放的计量估算研究

根据黑河市森林调查的实测数据和1971—2011年间森林火灾的统计资料,采用地理信息系统(GIS)技术,通过大量野外火烧迹地的调查,结合实验室的控制实验,确定森林火灾碳排放的各计量参数,并利用排放因子的方法,估算了黑河市41年间森林火灾碳排放量和含碳气体排放量。结果表明:41年间黑河市森林火灾碳排放量为4.00×10⁷ t,年均排放量为9.76×10⁵ t,约占全国年均森林火灾碳排放量的8.63%; 含碳气体CO₂、CO、CH₄和非甲烷烃(NMHC)的排放量分别为1.24×10⁸、6.51×10⁶、4.30×10⁵和3.47×10⁵ t,年均排放量分别为3.01×10⁶、1.59×10⁵、1.05×10⁴和8.46×10³ t,分别占全国年均森林火灾各含碳气体排放量的7.42%、5.86%、9.37%和7.49%。研究发现针阔混交林型的森林火灾面积占总过火林地面积的42.73%,由于该林型燃烧效率较低,其森林火灾中的碳排放量仅占排放总量的29.61%,且CO₂的排放因子较低,其CO₂排放量仅占CO₂总排放量的30.11%。同时研究表明,黑河市年均碳排放对该市的碳循环与碳平衡产生重要影响,针对研究结果提出了合理的林火管理路径。     

火电厂排放源对张家港市冬季空气质量的影响

为了解张家港市火电厂排放源对空气质量的影响程度,利用WRF-Chem空气质量模式分别模拟了采用2013年火电厂排放源和2016年预测情景排放源的张家港市冬季各污染物的浓度,分析了现状以及预测排放情景下火电厂对污染物浓度的贡献。结果表明:2013年张家港市火电厂排放源对冬季SO_2,NO_x,PM_(2.5),PM_(10)的小时浓度贡献为60%,50%,14%,20%,火电厂排放源的水平影响范围为5~10km,垂直高度可延伸至2km,受烟流抬升高度的影响,电厂源对100~200m高度污染物浓度的贡献率最大,数值可以达到地面浓度贡献率的1.5倍;2016年采取减排措施后的预测情景表明,各污染物浓度明显减小,火电厂排放源对SO_2,NO_x,PM_(2.5),PM_(10)的小时浓度贡献最大值分别降低到25%,25%,5%,8%,而在垂直高度上,各污染物浓度下降比例最高为18.0%,15.5%,2.1%,3.8%。     

基于饮水点放牧半径的高寒植被演替过程研究

为了解大通河上游夏季牧场基于饮水点放牧半径范围的高寒植被演替过程,在祁连县默勒镇瓦日尕村夏季草场采用扣笼法进行调查。结果表明:随着饮水半径的缩小,草地植物由34种下降到25种,植物多样性显著下降(P0.05);草地优势种植物的株高、盖度、植物量、优势度均显著下降(P0.05);美丽风毛菊等阔叶杂类草的盖度、植物量、优势度均显著增加(P0.05);草地优良牧草比例显著下降(P0.05),杂类草比例逐渐增高。因此,草地植物种类、植被特征和群落组成均有一定变化,草地出现明显的退化趋势。     

Methane emissions from terrestrial plants over China and their effects on methane concentrations in lower troposphere

Methane (CH₄) is the most important greenhouse gas and reactive trace gas in the atmosphere. Recently, it has been reported that terrestrial plants can emit CH₄ under aerobic conditions, which may call for reevaluation of the inventory of CH₄ emissions in China. In this paper, those emissions over China and their effects on CH₄ concentrations in lower troposphere were investigated. Firstly, based on the work of Keppler et al., the aerobic plant CH₄ emission model (PLANTCH4) for China was established. And by using the database of normalized difference vegetation index (NDVI) derived from NOAA/AVHRR, the distribution of net primary productivity (NPP) over China was simulated, and thereby, for the first time, the amount and distribution of the newly identified source in China were estimated. Secondly, with the aid of the three-dimensional atmospheric chemistry model system (MM5-CALGRID), the effects of the emissions were studied. The results show that the annual aerobic plant CH4 emissions over China amount to 11.83 Tg, i.e. nearly 24% of Chinese total CH₄ emissions. And the major fraction (about 43%) comes from forests. When those emissions are considered in modeling, computed countrywide mean surface concentration of CH₄ is 29.9% higher than without them, with a maximum increase of 69.61 μg·m⁻³ in the south of Yunnan Province. In conclusion, to study CH₄ emissions from terrestrial plants over China may have important implications for correctly estimating the contribution of China to global CH₄ budget, and may call for a reconsideration of the role of CH₄ in global and regional environment and climate change. Supported by National High-Tech Research & Development Program of China (Grant No. 2006AA06A307), National Basic Research Program of China (Grant Nos. 2006CB403706 and 2006CB403703), and the Program for New Century Excellent Talents in University, and Nanjing University Talent Development Foundation     

Spatial distribution of black carbon emissions in China

Based on the official statistics, locally measured emission factors, and the vehicular emission factor model most suitable for China, we developed a black carbon (BC) emission inventory for 2008 in China and at a spatial resolution of 0.5°×0.5°. In 2008, the total BC emissions in China were 1604.94 Gg. Industry and the residential sector were the dominant contributors, estimated at 695.03 Gg and 636.02 Gg of BC, respectively. Together, these two source types contributed 82.9% of the total emissions. Emissions from transportation were 194.63 Gg, accounting for 12.1% of the total. Since emission contributions from different sectors showed significant spatial diversity among the 31 administrative districts, we divided the districts into four categories: industry contribution district, residential contribution district, industry and residential contribution district, and transportation contribution district. As for energy consumption, coal and biofuel contributed 51.0% and 32.2%, respectively, of the total emissions. Spatially, BC emissions in China were unevenly distributed, higher in the east and lower in the west, corresponding to regional economic development and rural population density. High emission districts, covering 5.7% of the territory, contributed 41.2% of the total emissions. Shanxi, Hebei, Shandong, Henan, and Sichuan were the largest contributors to national BC emissions.     

Estimation of emissions from field burning of crop straw in China

Emissions resulting from crop straw field burning in China, which have caused serious environmental problems in China, are estimated in this paper. From the county-level data of crop production in 2000-2003 from the government statistics, taking into account the ratio of residue and grain, the total amount of crop straw production is estimated to be about 600 Tg per year, 76% of which are rice, wheat and corn straw. With reference to the data of living standards, the percentage of crop straw burnt in fields for counties are obtained and consequently the total amount of burnt straws is approximately 140 Tg/year. With the emission factors from literature and experiments, appropriate emission factors have been obtained. The total amounts of PM, SO2, NOx3, NH3, CH4, BC, OC, VOC, CO, CO2 emissions from field burning of crop straw in China are estimated. All emissions are presented at county level. Some pollutants, such as BC, VOC, OC, CO and CO2, are contributing a major portion to the total emissions of China. This paper uses a map with resolution of 0.2°×0.2°to present the PM emissions distribution from crop straw burnt in 2003. The results show a significant regional unevenness of emissions, with larger amounts of pollutions coming from the provinces in eastern and northeast China. The regions with higher emissions per unit area are located as a belt stretching from northeast China to eastern China.     

云南糯扎渡保护区电站建设水淹区植被资源调查

为了掌握水电站建设水淹区的植被资源决策数据和信息，利用3S技术对糯扎渡省级自然保护区水淹区的植被资源进行调查。结果表明，被淹没的植被类型和面积分别为：季风常绿阔叶林313hm^2，占保护区面积的2．8％；落叶季雨林443hm^2，占33．5％；思茅松林10hm^2，占0．2％；竹林385hm^2，占41．2％；干热河谷稀树草丛73hm^2，占65．2％；灌木林9hm^2，占2．2％。在水电站建设水淹区的植被资源调查中3S技术展现了速度快、精度高且经济的特点。     

新疆喀纳斯保护区森林碳储量及碳密度研究

基于森林资源二类清查数据资料,利用材积源生物量法和平均生物量法,计算新疆喀纳斯国家自然保护区内森林植被的碳储量及其空间分布。结果表明:保护区内森林植被碳储量为3.004 7 Tg,平均碳密度为49.58 Mg/hm²。不同植被类型碳储量从大到小排序为:乔木林地、灌木林地、疏林地、散生木,其中乔木林地碳储量占到森林植被总碳储量的90.18%,各乔木林地的平均碳密度为68.87 Mg/hm²。区域分布上,林分碳储量、碳密度的空间分布呈现出西南高东北低的趋势; 而保护区内成、过熟林分的碳储量共占乔木林地碳储量的79.89%,若对现有森林采取合理的经营管理,可增加其碳汇能力。     

中国短链氯化石蜡排放清单和预测

通过对氯化石蜡(CPs)生产和消费行业的调查和文献调研, 将短链氯化石蜡(SCCPs)的排放按生产、增塑剂、阻燃剂和金属切削液4个行业进行测算, 给出中国SCCPs排放清单和2007?2011年SCCPs年排放 量。中国2011年SCCPs的排放总量为1788.67吨, 其中对大气的排放量达到498.32吨, 对水体的排放达到1290.35吨; 排放量最大的是金属切削液的使用过程。若不采取控制措施, 到2016年SCCPs的年排放量将达到 2562.51吨, 对生态环境和人体健康存在巨大威胁。     

Estimated HCFC-142b emissions in China: 2000–2050

1-Chloro-1,1-difluoroethane(HCFC-142b)was both ozone depleting substance under restriction of the Montreal Protocol on Substances that Deplete the Ozone Layer(Montreal Protocol)and potent greenhouse gas with high GWP.Controlling its emissions in China will contribute to both mitigating climate change and protecting ozone.A national emission inventory of HCFC-142b for China during 2000–2012 was established and projected to2050 based on the 2006 IPCC Guidelines for National Greenhouse Gas Inventories and the Montreal Protocol,showing that(i)in contrast to the downward trend revealed by existing researches,HCFC-142b emissions kept increasing from 0.1 kt/y in 2000 to the peak of 14.4 kt/y in2012,making China a crucial contributor to global HCFC-142b emissions and(ii)for future emission projections,a continuous increase from 14.9 kt/y in 2013 to 97.2 kt/y in2050 was anticipated under the business-as-usual(BAU)scenarios,while a reduction of about 90%of the projected BAU emissions would be obtained by fulfilling the Montreal Protocol,namely an accumulative mitigation of 1578kt HCFC-142b from 2013 to 2050,equal to 103 kt ODP and 3504 Tg CO2emissions.Emissions from each province in 2012 were also estimated to identify key emission areas.Among the 31 mainland provinces in China(Hong Kong,Macao,and Taiwan were not included),Jiangsu,Zhejiang,Shandong,and Guangdong had the highest emission ratesin 2012(2.06,1.85,1.52,and 1.04 kt/y,respectively);Zhejiang,Jiangsu,and Shanghai exhibit the strongest emission strength(0.83,0.59,and 0.54 t/km2,respectively),much higher than the average national level of 0.33t/km2.     

北京地区甲烷排放的变化趋势和分布特征

依据国际上编制国家甲烷清单的方法,建立了北京城市尺度的甲烷排放清单,分析了北京地区甲烷排放的分布规律,并按10km×10km网格给出了北京地区甲烷排放强度的分布状况。1999年北京地区甲烷排放总量为296.29Gg,大约占全国排放总量的0.9%。其中,最主要的甲烷排放源为城市垃圾和化石燃料。城市垃圾源强为161.60Gg,占北京地区甲烷排放总量的54.6%;化石燃料源强为96.08Gg,占排放总量的32.4%。这充分反映了北京作为一特大城市甲烷排放受人为源干预强的特征。