退耕还林地桦木林生态系统碳素密度、贮量与空间分布

对退耕还林5年生的桦木林生物量、碳素密度、碳贮量及其空间分布进行测定。结果表明,桦木各器官的碳素密度在0.4519~0.5137gC.g-1,排列顺序为枝>干>叶>根颈>粗根>中根>细根;死地被物层的碳素含量为0.3953gC.g-1,土壤平均碳素密度为0.0150gC.g-1,随土层深度的增加,各层次土壤碳素密度呈逐渐减少的趋势;桦木林生态系统总的碳贮量为127.9298tC.hm-2,其中乔木层为21.9282tC.hm-2,占整个生态系统的17.14%,死地被物为0.3401tC.hm-2,占0.27%,林地土壤(0~60cm)为105.6615tC.hm-2,占82.59%;桦木各器官的碳贮量与其生物量成正比例的关系,树干的生物量最大,其碳贮量也最大,占乔木层碳贮量的57.33%;5年生桦木林年净生产力为8.9912t.hm-2.a-1,有机碳年固定量为4.4537tC.hm-2.a-1。较之退耕前,桦木林生态系统碳贮量增加15.4797t.hm-2。     

广西大青山南亚热带马尾松、杉木混交林生态系统碳素积累和分配特征

选取广西大青山3个13年生马尾松、杉木混交林样区,研究其生态系统的碳素积累和分配特征。结果表明,混交林中两个树种的碳素含量各异。马尾松干、根、枝的碳素含量较高,分别为58·6%、56·3%、51·2%,叶和皮含量较低,变化幅度为46·8%~56·3%。各器官中按碳素含量的高低排列顺序为:干>根>枝>皮>叶;杉木皮、叶、干的碳素含量较高,分别为52·2%、51·8%、50·2%,碳素含量从高到低依次为:皮>叶>干>根>枝。从两个树种各器官碳总含量来看,马尾松要高于杉木。灌木层、草本层及地表凋落物层碳素平均含量分别为44·1%、33·0%及48·3%。土壤3个层次(60cm深)碳素含量为1·45%~1·84%,各层次碳素含量分布不均,表层(0~20cm)土壤碳素含量较高。针叶混交林乔木层生物量(t·hm-2)为85·35~101·35,平均为93·83,且均以马尾松生物量居多(占75·7%~82·6%)。混交林生态系统碳库的空间分布序列为土壤层>植被层>凋落物层。植被层的碳贮量平均为51·91t·hm-2,占整个生态系统碳总贮量的29·03%;乔木层碳贮量占整个生态系统的23·90%,占植被层碳贮量的97·7%。乔木层碳贮量中,马尾松占的比例较大,为65·39%。碳贮量在两个树种各器官中的分配,基本与各自的生物量成正比例关系,树干的碳贮量均最高,马尾松、杉木的树干碳贮量分别占各自碳贮量的53·23%、55·57%,树干的碳总贮量占乔木层碳总贮量的54%。其次,两个树种根也占较大比例,树根碳总贮量占乔木层碳总贮量的19·22%。马尾松、杉木枝、皮在各自碳的贮量中分配不同,马尾松枝占的比例要大于皮,而杉木则相反;凋落物层碳贮量平均为3·25t·hm-2,仅占1·82%;林地土壤层(0~60cm)碳贮量是相当可观的,平均为123·43t·hm-2,占69·02%。马尾松、杉木混交林年净生产力为11·46t·hm-2·a-1,有机碳年净固定量为5·96t·hm-2·a-1,折合成CO2的量为21·88t·hm-2·a-1。     

毛竹(Phyllostachy pubescens)、杉木(Cunninghamia lanceolata)人工林生态系统碳贮量及其分配特征

研究比较了湖南会同林区毛竹、杉木人工林生态系统碳含量和碳贮量分配特征,结果表明,15年生杉木各器官碳含量在47.15%～50.43%之间,不同器官碳含量高低依次为树干、树叶、树皮、树枝、树根;毛竹不同器官碳含量波动在44.51%～49.91%,各器官碳含量高低依次为竹鞭、竹枝、竹叶、竹干、竹蔸、竹根,但是毛竹不同器官碳含量与年龄之间没有明显变化规律。林地土壤3个层次(60cm深)碳素含量为0.746%～2.390%,各层次碳素含量分布不均,表层(0～20cm)土壤碳素含量和碳贮量最高。毛竹、杉木人工林生态系统碳贮量分别为166.34tC·hm-2和150.19tC·hm-2,并且其碳贮量空间分布格局基本一致,土壤层是主要部分,其次为乔木层,林下植被层和凋落物层所占比例最小。其中,毛竹林土壤层有机碳贮量占83.92%,乔木层占15.38%,林下植被和凋落物层分别占0.38%和0.32%;杉木人工林土壤层碳贮量占62.03%,乔木层占34.99%,林下植被和凋落物层分别占0.70%和2.28%。另外,碳贮量在两个树种各器官中的分配,基本与各自的生物量成正比例关系。从植被年固定碳量来看,毛竹林为9.94tC·hm-2·a-1,相当于年固定CO2量为36.44tCO2·hm-2·a-1,是杉木林的1.39倍。     

湖南会同不同退耕还林模式初期碳密度、碳贮量及其空间分布特征

对湖南会同5种退耕还林模式初期森林生态系统碳密度、碳贮量及其空间分布特征进行了研究。结果表明:主要造林树种马尾松、樟树、杜英、乐昌含笑、红花木莲不同器官的平均碳密度分别为:0.5296、0.5188、0.5178、0.5376、0.5355gC/g,树种间同一器官的平均碳密度排序为:树干树根树叶树枝树皮;5种退耕还林模式中活地被物层、死地被物层碳密度分别介于0.4380—0.5380gC/g、0.5060—0.5200gC/g之间,土壤层(0—60cm,下同)平均有机碳密度介于0.00786—0.01485gC/g之间;退耕还林3a后,乐昌含笑×红花木莲混交林、杜英×乐昌含笑混交林、杜英×樟树混交林、樟树林土壤层有机碳密度比原坡耕地分别提高了53.57%、39.19%、38.57%、24.82%,而马尾松林地下降了18.72%。林木不同器官中的碳贮量基本上与各器官的生物量成正比例,同一造林时间的4种模式中,以杜英×樟树混交林各器官的碳贮量最大,为1.219tC/hm2,杜英×乐昌含笑混交林最小,仅为0.199tC/hm2,均以干根碳贮量为最大,占其各器官碳贮量的57.50%以上。5种退耕还林模式恢复初期的生态系统中,土壤层碳贮量最大,为74.518—119.312tC/hm2,占96.180%以上,植被层为其次,在0.633—2.960tC/hm2之间,仅占0.642%—3.820%,死地被物层为最小。退耕后,樟树林、杜英×樟树混交林、乐昌含笑×红花木莲混交林、杜英×乐昌含笑混交林生态系统碳贮量分别增加了19.477、27.722、41.643、26.821tC/hm2,马尾松林下降了1.675tC/hm2。     

四川西北部亚高山云杉天然林生态系统碳密度、净生产量和碳贮量的初步研究

该文利用野外实际调查数据对四川西北部亚高山云杉(Picea asperata)天然林碳密度、净生产量、碳贮量及其分布进行了分析,结果表明,在调查区域,云杉天然林分平均生物量为230.37×10³ kg·hm^-2,其中乔木层为212.77×10³ kg·hm^-2,占林分生物量的92.30%。云杉天然林生态系统各组分的平均碳密度为树干57.85%,树皮47.12%,树枝51.22%,树叶48.27%和树根52.39%,灌木层平均碳密度49.91%,草本层平均碳密度46.34%,地被层平均碳密度43.21%,枯落物层平均碳密度39.44%,土壤碳密度平均值为1.41%,随土层深度增加各层次土壤碳密度逐渐减少。云杉林平均生态系统总碳贮量为273.79×10³ kg·hm^-2,其中乔木层109.30×10³ kg·hm^-2,占云杉林生态系统总碳贮量的39.92%,灌木层5.69×10³ kg·hm^-2,占2.08%,草本层1.26×10³ kg·hm^-2,占0.46%,地被物层0.60×10³ kg·hm^-2,占0.22%,枯落物层0.83×10³ kg·hm^-2,占0.30%,林内土壤(0~100 cm)碳贮量为156.11×10³ kg·hm^-2,占57.01%。云杉林的碳库分布序列为土壤(0~100 cm)>乔木层>灌木层>草本层>枯落物层>地被物层。云杉天然林分平均净生产总量为6 838.5 kg·hm^-2·a^-1,碳素年总净固量平均为3 584.98 kg·hm^-2·a^-1,其中乔木层净生产量为4 676 kg·hm^-2·a^-1,占林分总量的68.38%,碳素年平均固定量2 552.99 kg·hm^-2·a^-1,占林分总量的71.21%。     

米老排人工林碳素积累特征及其分配格局

在生物量调查的基础上,对桂西南地区28年生米老排人工林生态系统的碳素积累特征及分配格局进行了研究.结果表明:米老排各器官碳含量在522.8～560.2 g·kg-1,大小排序为:树叶(560.2 g·kg-1)＞树干(542.8 g·kg-1)＞树根(530.9 g·kg-1)＞树皮(530.8 g·kg-1)＞树枝(522.8 g·kg-1);土壤碳含量以表土层最高,且随土层深度的增加而降低;米老排人工林乔木层碳贮量为147.90 t·hm-2,其中,树干占乔木层碳贮量的63.72％;米老排人工林生态系统碳贮量为285.36 t·hm-2,各组分的分配顺序为乔木层＞土壤层＞凋落物层＞灌木层＞草本层;植被层碳贮量为土壤层(0～100 cm)的1.1倍.     

鼎湖山马尾松林生态系统碳素分配和贮量的研究

鼎湖山马尾松林中 ,马尾松各器官碳含量平均为 5 4.46%,灌木层植物 48.1 0 %,草本层植物40 .2 1 %,地表现存凋落物层 5 4.40 %,以上各组分总平均为 49.2 9%。土壤碳密度为 7.3 7kg· m- 2 (深 1 0 0cm)。生态系统各组分碳贮量分别为 :乔木层 68.876t·hm- 2 ,林下植物层 6.0 3 0 t· hm- 2 ,凋落物层 5 .892 t·hm- 2 ,土壤层 73 .70 5 t· hm- 2。根据研究结果 ,还对广东省马尾松林的现有碳贮量和碳吸存潜力进行了估算和讨论。     

山西油松人工林生态系统生物量、碳积累及其分布

油松是我国北方主要的造林树种之一,准确估计油松人工林生态系统的生物量及碳储存对研究区域人工林的碳储功能具有重要意义。本研究采用固定样地方法对38年生油松人工林的生物量、碳贮量及其空间分布进行测定,并估算了其净生产力与年净碳固定量。结果表明:(1)油松单木生物量与胸径和树高之间均存在着紧密的相关关系。林分平均生物量为145.35t.hm-2,其中乔木层为123.98t.hm-2,占林分生物量的85.30%。(2)油松人工林生态系统各组分碳含量为:树干0.5032gC.g-1,树皮0.4887gC.g-1,树枝0.5414gC.g-1,树叶0.4774gC.g-1,树根0.4862gC.g-1;灌木层0.4468gC.g-1;草本层0.4417gC.g-1;枯落物层0.4112gC.g-1;土壤层(0～100cm)0.0090gC.g-1,随土层深度增加各层次土壤碳含量逐渐减少。(3)油松人工林生态系统总碳贮量为172.95t.hm-2,各层碳贮量的大小顺序为土壤(0～100cm)(102.07t.hm-2)>乔木层(62.08t.hm-2)>枯落物层(7.75t.hm-2)>灌木层(0.58t.hm-2)>草本层(0.47t.hm-2)。油松各器官的碳贮量与其生物量呈正比,树干的生物量最大,其碳贮量也最大,占乔木层碳贮量的58.80%。(4)油松人工林年净生产力为10.19t.hm-2.a-1,有机碳年固定量为5.03tC.hm-2.a-1。     

东灵山暖温带落叶阔叶林生物量和能量密度研究

研究了辽东栎 (Quercusliaotungensis)林生物量、能量分配和能量密度过程 ,结果表明 ,辽东栎林的生物量在60～ 2 0 0t·hm- 2 之间 ,乔木层的生物量在 50～ 1 60t·hm- 2 之间 ,在林分中所占比例为 80 %～ 98% ,辽东栎生物量在林分中所占比例从 40 %到 1 0 0 % ,净初级生产力从 5t·hm- 2 ·a- 1 到 2 4t·hm- 2 ·a- 1 。辽东栎群落能量现存密度为 830 0 0kcal·m- 2 ,其中乔木层占 96 .65 %、灌木层占 3 .1 2 %、草本层占 0 .2 3 %。乔木层中各器官能量密度排列顺序是树干 >树根 >树枝 >树叶 ,比例是 4 :3 :2 :1 ,灌木层中 ,各器官能量密度顺序是干 >枝 >根 >叶。最后给出了该类森林生态系统变化的生物量和能量概念模式 ,为下一步建立抽象的数学模型 ,建立可操作能实用的计算机模拟模型打下了基础。     

毛竹(Phyllostachy pubescens)、杉木(Cunninghamialanceolata)人工林生态系统碳贮量及其分配特征

研究比较了湖南会同林区毛竹、杉木人工林生态系统碳含量和碳贮量分配特征,结果表明, 15年生杉木各器官碳含量在47.15%～50.43%之间,不同器官碳含量高低依次为树干、树叶、树皮、树枝、树根;毛竹不同器官碳含量波动在44.51%～4991%,各器官碳含量高低依次为竹鞭、竹枝、 竹叶、竹干、竹蔸、竹根,但是毛竹不同器官碳含量与年龄之间没有明显变化规律。林地土壤3个层次(60cm深)碳素含量为0.746%～2.390%,各层次碳素含量分布不均,表层（0～20cm）土壤碳素含量和碳贮量最高。毛竹、杉木人工林生态系统碳贮量分别为166.34tC•hm^-2和150.19tC•hm^-2,并且其碳贮量空间分布格局基本一致, 土壤层是主要部分,其次为乔木层,林下植被层和凋落物层所占比例最小。其中,毛竹林土壤层有机碳贮量占83.92%,乔木层占15.38%,林下植被和凋落物层分别占0.38%和0.32%;杉木人工林土壤层碳贮量占62.03%,乔木层占34.99%,林下植被和凋落物层分别占0.70%和2.28%。另外,碳贮量在两个树种各器官中的分配,基本与各自的生物量成正比例关系。从植被年固定碳量来看,毛竹林为9.94 tC•hm^-2•a^-1,相当于年固定CO2量为36.44 tCO2•hm^-2•a^-1,是杉木林的1.39倍。     

我国主要森林生态系统碳贮量和碳平衡

在广泛收集资料的基础上,估算了我国主要森林生态系统的碳贮量和碳平衡通量,分析了它们的区域特征。主要结果如下：1)我国森林生态系统的平均碳密度是258.83t·hm^-2,基本趋势是随纬度的增加而增加;其中植被的平均碳密度是57.07t·hm^-2,随纬度的增加而减小;土壤碳密度约是植被碳密度的3．4倍,其区域特点与植被碳密度呈相反趋势,随纬度升高而增加;凋落物层平均碳密度是8.21t·hm^-2,随水热因子的改善而减小。2)森林生态系统有机碳库包括植被、土壤和凋落物层3个部分,采用林业部调查规划设计院1989～1993年最新统计的我国森林资源清查资料,估算我国主要森林生态系统碳贮量为281.16×10⁸t,其中植被碳库、土壤碳库、凋落物层碳库分别为62.00×10⁸t、210.23×10⁸t、8.92×10⁸t。落叶阔叶林、暖性针叶林、常绿落叶阔叶林、云冷杉(Picea-Abies)林、落叶松(Larix)林占森林总碳贮量的87％,是我国森林主要的碳库。3)我国森林生态系统在与大气的气体交换中表现为碳汇,年通量为4.80×10⁸t·a^-1,基本规律是从热带向寒带,碳汇功能下降,这取决于系统碳收支的各个通量之间的动态平衡;阔叶林的固碳能力大于针叶林。我国森林生态系统可以吸收生物物质、化石燃料燃烧和人口呼吸释放总碳量(9.87×10⁸t·a^-1)的48.7％。     

Ecological Footprint: Refining the carbon Footprint calculation

Within the Ecological Footprint methodology, the carbon Footprint component is defined as the regenerative forest capacity required to sequester the anthropogenic carbon dioxide emissions that is not absorbed by oceans. A key parameter of the carbon Footprint is the Average Forest Carbon Sequestration (AFCS), which is calculated from the net carbon sequestration capacity of forests ecosystems.The aim of this paper is to increase the clarity and transparency of the Ecological Footprint by reviewing the rationale and methodology behind the carbon Footprint component, and updating a key factor in its calculation, the AFCS. Multiple calculation options have been set to capture different rates of carbon sequestration depending on the degree of human management of three types of forest considered (primary forests, other naturally regenerated forests and planted forests). Carbon emissions related to forest wildfires and soil as well as harvested wood product have been included for the first time in this update of the AFCS calculation. Overall, a AFCS value range of 0.73 ± 0.37 t C ha⁻¹ yr⁻¹ has been identified. The resulting carbon Footprint and Ecological Footprint values have then been evaluated based on this value range. Results confirm that human demand for ecosystem services is beyond the biosphere's natural capacity to provide them.     

Are Swedish forest soils sinks or sources for CO<Subscript>2</Subscript>—model analyses based on forest inventory data

Forests soils should be neither sinks nor sources of carbon in a long-term perspective. From a Swedish perspective the time since the last glaciation has probably not been long enough to reach a steady state, although changes are currently very slow. In a shorter perspective, climatic and management changes over the past 100 years have probably created imbalances between litter input to soils and organic carbon mineralisation. Using extant data on forest inventories, we applied models to analyse possible changes in the carbon stocks of Swedish forest soils. The models use tree stocks to provide estimates of tree litter production, which are fed to models of litter decomposition and from which carbon stocks are calculated. National soil carbon stocks were estimated to have increased by 3 Tg yr⁻¹ or 12–13 g m⁻² yr⁻¹ in the period 1926–2000 and this increase will continue because soil stocks are far from equilibrium with current litter inputs. The figure obtained is likely to be an underestimation because wet sites store more carbon than predicted here and the inhibitory effect of nitrogen deposition on soil carbon mineralisation was neglected. Knowledge about site history prior to the calculation period determines the accuracy of current soil carbon stocks estimates, although changes can be more accurately estimated. This article has previously been published in issue 82/3, under DOI .     

中国森林C汇功能基本估计

根据森林资源消长状况和未来变化趋势,对中国森林因Ｃ的现状和潜力进行了估计和预测．结果表明,中国森林目前Ｃ积累高于Ｃ释放,年平均净固Ｃ量为０．８６２７×１０８ｔ·ａ－１,在未来２０年内中国森林净固Ｃ能力约增加７７３×１０４ｔ·ａ－１．到２０００年,中国森林固Ｃ能力将达到１．４６９７×１０８ｔ·ａ－１．     

Present status and rate of carbon sequestration of forest vegetation in Jilin Province,Northeast China北大核心CSCD

Aims Forests represent the most important component of the terrestrial biological carbon pool and play an important role in the global carbon cycle. The regional scale estimation of carbon budgets of forest ecosystems, however, have high uncertainties because of the different data sources, estimation methods and so on. Our objective was to accurately estimate the carbon storage, density and sequestration rate in forest vegetation in Jilin Province of China, in order to understand the role of the carbon sink and to better manage forest ecosystems. Methods Vegetation survey data were used to determine forest distribution, size of area and vegetation types regionally. In our study, 561 plots were investigated to build volume-biomass models; 288 plots of shrubs and herbs were harvested to calculate the biomass of understory vegetation, and samples of trees, shrubs and herbs were collected to analyze carbon content. Carbon storage, density and sequestration rate were estimated by two forest inventory data (2009 and 2014), combined with volume-biomass models, the average biomass of understory vegetation and carbon content of vegetation. Finally, the distribution patterns of carbon pools were presented using ArcGIS soft ware. Important findings Understory vegetation biomass overall was less than 3% of the tree layer biomass, varying greatly among different forest types and even among the similar types. The carbon content of trees was between 45.80% 52.97%, and that of the coniferous forests was higher than that of the broadleaf forests. The carbon content of shrub and herb layers was about 39.79% 47.25% and 40%, respectively. Therefore, the vegetation carbon conversion coefficient was 0.47 or 0.48 in Jilin Province, and the conventional use of 0.50 or 0.45 would cause deviation of ±5.26%. The vegetation carbon pool of Jilin Province was at the upper range of regional carbon pool and had higher capacity of carbon sequestration. The value in 2009 and 2014 was 471.29 Tg C and 505.76 Tg C, respectively, and the total increase was 34.47 Tg C with average annual growth of 6.89 Tg C•a1. The corresponding carbon sequestration rate was 0.92 t•hm 2•a1. The carbon density rose from 64.58 t•hm 2 in 2009 to 66.68 t•hm2 in 2014, with an average increase of 2.10 t•hm2. In addition, the carbon storage of the Quercus mongolica forests and broadleaved mixed forests, accounted for 90.34% of that of all forests. The carbon increment followed the order of young > over-mature > near mature > middle-aged > mature forests. The carbon sequestration rate of followed the order of over-mature > young > near mature > middle-aged > mature forests. Both the carbon increment and the carbon sequestration rate of mature forests were negative. Furthermore, spatially the carbon storage and density were higher in the east than in the west of Jilin province, while the carbon increment was higher in northeast and middle east than in the west. The carbon sequestration rate was higher in Tonghua and Baishan in the south, followed by Jinlin in the middle and Yanbian in the east, while Baicheng and Songyuan, etc. in west showed negative values.     

Are Swedish forest soils sinks or sources for CO<Subscript>2</Subscript>—model analyses based on forest inventory data

Forests soils should be neither sinks nor sources of carbon in a long-term perspective. From a Swedish perspective the time since the last glaciation has probably not been long enough to reach a steady state, although changes are currently very slow. In a shorter perspective, climatic and management changes over the past 100 years have probably created imbalances between litter input to soils and organic carbon mineralisation. Using extant data on forest inventories, we applied models to analyse possible changes in the carbon stocks of Swedish forest soils. The models use tree stocks to provide estimates of tree litter production, which are fed to models of litter decomposition and from which carbon stocks are calculated. National soil carbon stocks were estimated to have increased by 3 Tg yr⁻¹ or 12–13 g m⁻² yr⁻¹ in the period 1926–2000 and this increase will continue because soil stocks are far from equilibrium with current litter inputs. The figure obtained is likely to be an underestimation because wet sites store more carbon than predicted here and the inhibitory effect of nitrogen deposition on soil carbon mineralisation was neglected. Knowledge about site history prior to the calculation period determines the accuracy of current soil carbon stocks estimates, although changes can be more accurately estimated.     

陆地植被的固碳功能与适用于碳贸易的生物固碳方式

碳贸易的核心问题是要有足够的碳封存量在抵消CO₂的排放之后还能有碳额度进入市场买卖。该文结合固碳概念,从固碳技术、减量成本、对生态系统碳汇功能的影响等多方面对目前存在的和有潜力的各种减排与固碳途径进行了比较分析,认为陆地植被对CO₂的吸收是最安全有效的固碳过程,它们能够在一定的浓度范围内吸收CO₂,从而节省分离、提纯等技术的费用。进而该文分别对森林、草地、农田等3种陆地植被的固碳功能与不同固碳策略对固碳效果的影响两个方面进行详细具体的比较分析,得出森林生态系统具有强大的碳吸收能力,草地与农田土壤有机碳库在固碳方面的作用也十分显著。最后结合我国实际,提出4项适用于碳贸易的生物固碳方式,即保护天然林,推广种植速生丰产人工林;保育天然草地、建设人工草地;建立规模化沼气产业链;注重利用边际土地种植生物质能源,促进生物质能源的开发。     

Current stocks and potential of carbon sequestration of the forest tree layer in Qinghai Province,China北大核心CSCD

Aims Our objective was to estimate the carbon storage in the forest tree layer in Qinghai Province, China. Methods Based on forest resource inventory data and field investigation data, we estimated the carbon storage, sequestration rate and potentials in the forest tree layer in the Qinghai Province. Important findings The carbon density and total carbon storage of forest tree layer in Qinghai Province was 76.54 Mg·hm-2 and 27.38 Tg, respectively, of which four forest types (Picea spp. forest, Cupressus funebris forest, Betula spp. forest and Populus spp. forest) accounted for 86.67% while their areas were 96.23% of total forest areas in Qinghai. The carbon density and carbon storage of Picea spp. forest was 106.93 Mg·hm-2 and 14.78 Tg, respectively, which was the largest among all forest types. The carbon storage of the forest tree layer at different stand ages followed the sequence of over-mature forest > middle-aged forest > mature forest > near-mature forest > young forest. In addition, the carbon storage of forest tree layer in the province increased from 23.30 Tg in 2003 to 27.38 Tg in 2011. The average annual growth of carbon and carbon sequestration rate were 0.51 Tg and 1.06 Mg·hm-2·a-1, respectively. The maximum and minimum of carbon sequestration rate were respectively found in Cupressus funebris forest (0.44 Mg·hm-2·a-1) and Betula spp. forest (-1.06 Mg·hm-2·a-1). The mean carbon sequestration potential reached 8.50 Tg in 2011, with the highest value found in Picea spp. forest (3.40 Tg). These findings suggested high carbon sequestration potential of forest tree layer in Qinghai Province. Therefore, the carbon storage in Qinghai Province could be increased through better forest management and utilization. © 2018 Editorial Office of Chinese Journal of Plant Ecology. All rights reserved.     

紫色土人工林生态系统碳库与碳吸存变化

采用时空代换法,以福建省宁化县严重退化紫色土人工林生态系统为对象,按侵蚀强度由强到弱选取4种生态恢复措施Ⅰ、Ⅱ、Ⅲ、Ⅳ,对比研究了碳库与碳吸存能力．结果表明,随着恢复程度的提高,生态系统的碳吸存能力逐渐增加,即Ⅰ<Ⅱ<Ⅲ<Ⅳ,4种措施生态系统碳库分别为1．4、8．5、25．6和37．6t·hm^-2;CO2年同化量分别是712．87、1458．01、9718．10和11109．56k·hm^-2．可见,恢复过程中的生态系统是本地区重要的碳汇之一．水土保持工程措施与生物措施相结合应是退化生态系统生态恢复的重要手段,但是减少人为干扰才是目前较为合理的恢复策略,使森林生态系统成为大气中CO2的一个重要的碳汇．     

Development and validation of a liquid chromatographic method for Casiopeina IIIi in rat plasma

In order to measure changes in physiological CO concentrations in blood with good accuracy, a method was developed using gas chromatography with flame ionisation detection (250 degrees C). A nickel catalyst system was fitted to convert CO to methane at 375 degrees C after separation with a molecular sieve column at 35 degrees C. Helium was used as carrier at 30 ml/min. Porcine or human blood (400 microl) was sampled in gastight tubes and treated with sulfuric acid and saponin (800 microl). Accuracy was 1.4% and 1.5% (RSD), respectively. Precision was 2.8% (porcine blood). Limit of detection was 0.01 nmol/ml gas and limit of quantification 12 nmol/ml blood. Calibration was made in the interval 12-514 nmol/ml blood (corresponding to 0.1-6% COHb). Samples were stable for at least a month at +4 degrees C. This paper describes a method with high sensitivity and good accuracy, suitable for analysis of low CO concentrations.