土地利用方式对土壤有机碳和碳库管理指数的影响

土壤碳库管理指数反映土壤管理的科学性.对比研究了干热河谷新银合欢林、苏门答腊金合欢林、大叶相思林、印楝林、荒地和旱耕地土壤有机碳(SOC)、易氧化有机碳(ROC)含量和土壤碳库管理指数.结果表明:6种土地利用方式下SOC和ROC含量范围分别为4.22～5.92 g·kg-1和1.34～2.33 g·kg-1.各利用方式...     

Dynamics of soil carbon stock,total nitrogen,and associated soil properties since the conversion of Acacia woodland to managed pastureland,parkland agroforestry,and treeless cropland in the Jido Komolcha District,southern Ethiopia

ABSTRACT

In the arid, low biomass producing areas of Ethiopia, Acacia woodlands suffered a severe degradation due to exploitation for various uses, and conversion to grazing and cultivated lands. However, little is known on the impact of agricultural land uses on soil organic carbon (SOC), total nitrogen (TN) stocks, and other soil quality indicators. This study was planned to evaluate SOC and TN stock changes under parkland agroforestry (PAF), managed pastureland (MPL), and treeless cropland (TLCL) regimes by considering the remnant protected woodland (PWL) as a reference. We found that SOC and TN stocks were significantly higher in PWL and MPL areas. Conversion of Acacia woodlands to MPL, PAF, and TLCL resulted in the loss of SOC stock by 23, 50, and 56%, respectively. Higher SOC and TN stocks were found under PWL (144.3 Mg ha^?1) and MPL (108.2 Mg ha^?1). Significant changes in available phosphorous (P), exchangeable cations, and cation exchangeable capacity were observed following the woodland conversion to different land use types. Available P was the highest in MPL compared with the other land use regimes. Within the study area, the MPL land use type was the best land management option for protecting SOC and TN soil stocks.     

不同改造措施对马尾松低效林土壤活性有机碳的影响

通过马尾松低效林改造试验,研究了不同改造措施(全砍重造(QKCZ)、封山育林(FSYL)和补植混交(BZHJ))对土壤有机碳和活性有机碳的影响.结果表明:马尾松低效林改造后土壤有机碳(SOC)、微生物量碳(MBC)、水溶性有机碳(DOC)和易氧化碳(EOC)含量分别比未改造的马尾松低效林(对照,CK)增加了1.06～3.30 g·kg-1、16.81～142.29 mg·kg-1 (P ＜0.05)、12.83～43.71 mg· kg-1(P＜0.05)和0.16 g～0.54 g·kg-1(P＜0.05);不同改造措施马尾松林土壤活性有机碳占土壤有机碳的比例大小顺序,微生物量碳/有机碳(MBC/SOC)为FSYL＞ CK＞ QKCZ＞ BZHJ,易氧化碳/有机碳(EOC/SOC)为CK＞ BZHJ＞ FSYL＞ QKCZ,水溶性有机碳/有机碳(DOC/SOC)为BZHJ＞ CK＞ FSYL＞ QKCZ.说明3种马尾松低效林改造措施中QKCZ的土壤有机碳稳定性最好,更有利于土壤有机碳固存.     

几种人工林土壤碳储量研究

对鹤山几种不同人工林的土壤碳的研究 ,结果表明不同植被作用下的土壤碳储量存在差异。人工林地、草地土壤有机碳含量均随土壤深度增加而减少。在同一深度不同人工林有机碳含量比较 :木荷林土壤最高 ,大叶相思林土壤最低。全氮的变化趋势也与有机碳一样 ,随土壤深度增加而递减。土壤有机碳储量的计算结果为 :柠檬桉 10 5 6 7t·hm-2 ,湿地松10 4 6 1t·hm-2 ,马占相思 114 6 2t·hm-2 ,大叶相思 71 4 9t·hm-2 ,木荷 12 7 6 6t·hm-2 ,草地 89 31t·hm-2 。据此认为 ,植树造林是增加土壤有机碳积累的有效措施 ,其中以营造乡土树种木荷林效果最好     

西藏色季拉山西坡不同海拔梯度表层土壤碳氮变化特性的研究

为探讨海拔梯度变化对表层土壤(0～20 cm)全量养分的影响,以西藏色季拉山西坡的高山灌丛(AS)、杜鹃林(RF)、急尖长苞冷杉林(AGSF1-6)和林芝云杉林(PLLF)为试验对象,研究了林地土壤有机碳(SOC)、全氮(TN)、微生物生物量碳(MBC)、微生物生物量氮(MBN)、易氧化态碳(ROC)和颗粒有机碳(POC)的变化特征.结果表明:在色季拉山西坡,高海拔植被类型具有较高的土壤活性有机碳含量和分配比例.表层土壤SOC随着海拔的升高而增大.SOC最大的是AS,为77.167 g·kg-1,PLLF最低为22.351 g·kg-1.表层土壤TN随着海拔的升高而增大.TN最大的是AS,为2.430g·kg-1,PLLF最低为0.830 g·kg-1.表层土壤C/N最大者为AGSF4,达到了43.57,最小者是PLLF为26.93.海拔和林分对土壤MBC和MBN含量具有显著的影响.随着海拔高度的降低,POC占TOC含量的比率从44.81％降至19.32％,ROC占TOC含量的比率从41.72％降至7.07％.不同林地POC和ROC含量与SOC含量具有正相关关系.土壤活性有机碳与土壤总有机碳显著相关,土壤易氧化有机碳与颗粒有机碳的相关性也比较显著(p＜0.05).     

Carbon pools and temporal dynamics along a rotation period in Quercus dominated high forest and coppice with standards stands

Carbon pools in two Quercus petraea (sessile oak) dominated chronosequences under different forest management (high forest and coppice with standards) were investigated. The objective was to study temporal carbon dynamics, in particular carbon sequestration in the soil and woody biomass production, in common forest management systems in eastern Austria along with stand development. The chronosequence approach was used to substitute time-for-space to enable coverage of a full rotation period in each system. Carbon content was determined in the following compartments: aboveground biomass, litter, soil to a depth of 50 cm, living root biomass and decomposing residues in the mineral soil horizons. Biomass carbon pools, except fine roots and residues, were estimated using species-specific allometric functions. Total carbon pools were on average 143 Mg ha⁻¹ in the high forest stand (HF) and 213 Mg ha⁻¹ in the coppice with standards stand (CS). The mean share of the total organic carbon pool (TOC) which is soil organic carbon (SOC) differs only marginally between HF (43.4%) and CS (42.1%), indicating the dominance of site factors, particularly climate, in controlling this ratio. While there was no significant change in O-layer and SOC stores over stand development, we found clear relationships between living biomass (aboveground and belowground) pools and C:N ratio in topsoil horizons with stand age. SOC pools seem to be very stable and an impact of silvicultural interventions was not detected with the applied method. Rapid decomposition and mineralization of litter, indicated by low O-horizon pools with wide C:N ratios of residual woody debris at the end of the vegetation period, suggests high rates of turnover in this fraction. CS, in contrast to HF benefits from rapid resprouting after coppicing and hence seems less vulnerable to conditions of low rainfall and drying topsoil.     

亚热带日本落叶松人工林生态系统的碳素含量研究

基于35块样地调查数据,对亚热带日本落叶松人工林生态系统的碳素含量进行了分析。结果表明:(1)日本落叶松人工林生态系统碳素含量包括植被、凋落物与土壤三部分,其中乔木层601.896 1±29.562 4g/kg,灌木层537.958 0±34.783 9 g/kg,草本层416.107 5 g/kg,凋落物层550.927 8±30.566 4 g/kg,土壤层30.477 1±1.848 0 g/kg,表现规律为:乔木层凋落层灌木层草本层,地上部分地下部分,且乔木层、凋落物层和土壤层的碳素含量随着林分年龄和坡向的不同而变化。(2)日本落叶松植被层的碳素含量平均值为0.518 7 g/g,略高于国际上通用的转换率0.50 g/g,如果采用0.50 g/g来估算日本落叶松植被层的碳贮量与碳密度,会使得估算结果偏小。(3)日本落叶松乔木层不同器官碳素含量变化范围为561.499 3~645.106 8 g/kg,其高低顺序大致排列为:树干树枝树皮树根树叶,且随着林分年龄和坡向的不同而变化。     

长潭自然保护区不同功能区森林土壤有机碳分布规律

在分析长潭自然保护区不同功能区土壤有机碳分布时,本研究发现,不同功能区土壤有机碳差异显著（P〈0．05）,土壤有机碳含量为实验区〉缓冲区〉核心区;不同功能区各层土壤有机碳含量为：0～50cm土层土壤有机碳含量为实验区〉缓冲区〉核心区．50～100cm土层土壤有机碳含量为缓冲区〉实验区〉核心区,缓冲区土壤有机碳含量变化大于核心区与实验区。     

碳汇林业—兼论山东省碳汇造林

对碳汇林业的背景、相关概念、碳汇造林国内外现状、CDM造林再造林项目运行程序及设计书内容、造林再造林碳汇项目涉及的几个技术问题进行了综述,建议:山东具有碳汇造林的条件、积极争取碳汇造林项目、强化农用林和经济林的碳汇作用、加强干瘠山地、盐碱地及沿海防护林碳汇造林、加强中幼林的可持续经营管理、加紧实施山东森林碳汇储量与潜力研究、科学研究、人才培养及技术培训等。     

小兴安岭典型林分类型土壤有机碳含量状况比较分析

对3种典型林型（原始红松林、蒙古栎林、云冷杉林）的林下土壤有机碳含量及相关物理状况进行分析测定,并进行比较的结果表明：蒙古栎林容重最小,孔隙度最高,含水率最高,对土壤物理性质改良效果好;3种林分类型土壤有机碳含量平均值依次为：原始红松林〉云冷杉林〉蒙古栎林,差异极显著（P〈0．01）,原始红松林土壤有机碳含量最高,表层（0～10cm）土壤有机碳含量迭（26．73±3．15）g/kg;3种林型样地表层有机碳含量占总有机碳含量的质量分数比重很大,为41．22％～45．01％,而人类各种活动主要作用于土壤表层,可见减少人为对森林生态系统的干扰活动,可提高森林生态系统固碳能力。     

黄土区人工与天然植被对凋落物量和土壤有机碳变化的影响

在黄土丘陵区选择从耕地、草地、灌木林到乔木林样地,不同样地内设立1 m × 1 m(乔木10 m×10 m)的样方,分析样方内凋落物积累量、碳氮含量、土壤有机碳(SOC)和可溶性碳(DOC)含量变化.结果表明:天然草地、灌木林、乔木林凋落物积累量依次为5.3,12.1和32.4 t·hm-2;但人工灌木林和乔木林的凋落物积累量分别为6.7和11.4 t·hm-2,分别是天然灌木林和乔木林的1/2和1/3.随着植被的恢复,天然植被凋落物的C/N高于人工植被(刺槐林除外).与耕地SOC(4.67 g·kg-1)相比,天然灌木林地SOC提高5.9倍,人工灌木林地提高1.8倍;天然乔木林地提高8.0倍,而人工乔木林地仅提高4.0倍.凋落物积累量与0～20 cm土层土壤有机碳存在显著线性相关关系(R2>0.83),但20 cm以下线性相关关系不显著.凋落物积累量与0～10 cm土壤可溶性碳含量存在显著线性相关关系(R2>0.893),与10～60 cm土层线性相关关系不显著,与80～100 cm土壤可溶性碳存在显著线性负相关关系.     

Soil Carbon and Nitrogen Stocks Under Plantations in Gambo District,Southern Ethiopia

The effect of six plantation species in comparison to natural forest (NF) on soil organic carbon (SOC) and total nitrogen (TN) stocks, depth-wise distribution, biomass carbon (C), and N was investigated on plantations and cultivated lands on an Andic paleudalf soil in Southern Ethiopia. The SOC, N, and bulk density were determined from samples taken in 4 replicates from 10-, 20-, 40-, 60-, and 100-cm depth under each site. Similarly, the biomass C and N of the plantation species and understory vegetation were also determined. The SOC and N were concentrated in the 0- to 10-cm depth and decreased progressively to the 1-m depth. Next to the NF, Juniperous procera accrued higher SOC and N in all depths than the corresponding plantations. No evidence of significant difference on SOC and N distribution among plantations was observed below the 10-cm depth with minor exceptions. The plantations accrue from 133.62 to 213.73 Mg ha^–1 or 59.1 to 94.5% SOC, 230.4 to 497.3 Mg ha^–1 or 6.9 to 14.9% TBC and 420.37 to 672.80 Mg ha^–1 or 12.5 to 20% total C-pool of that under the NF. The N stock under Juniperous procera was the highest, while the lowest was under Eucalyptus globulus and Cupressus lusitanica. We suggest that SOC and N sequestration can be enhanced through mixed cropping and because the performance of the native species Juniperous procera is encouraging, it should be planted to restock its habitat.     

柳杉人工林皆伐后初期土壤有机碳和微生物量碳动态

本文研究了华西雨屏区柳杉人工林皆伐后1年内土壤有机碳和微生物量碳动态。结果表明:柳杉人工林皆伐林地土壤平均有机碳含量比对照(未皆伐林地)减小2.01 gC.kg-1,但差异不显著,而土壤平均有机碳储量及微生物量碳分别比对照减少20.97 tC.hm-2、6.68 mg.kg-1(P0.05);皆伐林地土壤有机碳含量及微生物量碳均随季节的变化而逐渐降低,但有机碳储量随季节的变化无明显减少趋势;皆伐林地土壤四季的有机碳含量、碳储量和微生物量碳差异不显著。皆伐对柳杉人工林土壤有机碳储量的影响主要表现在0~20 cm土层(P0.05);皆伐林地和对照在0~40 cm土层的微生物量碳和有机碳含量都表现出显著相关性(P0.05),但对照的相关性高于皆伐林地。总之,柳杉人工林转变为采伐迹地后,其初期土壤有机碳储量和微生物量碳都明显减少。     

北亚热带土地利用变化对土壤有机碳垂直分布特征及储量的影响

利用野外调查的方法,研究了北亚热带地区土地利用变化对土壤有机碳的垂直分布特征及储量的影响.研究结果表明:(1)除茶园土壤外,不同林分土壤有机碳含量均以0～10cm土层最大,随着土层深度的增加,含量总体表现为下降的趋势;茶园土壤有机碳含量在0～30cm土层范围内增加,30cm以后表现下降的趋势;(2)次生林转变成农耕地以后土壤有机碳含量平均下降21.1%,而转变成集约经营早竹林后,土壤有机碳含量平均下降近48.5%;1m深度以内,土壤有机碳平均含量由高到低的顺序为:茶园、灌木林、次生林、粗放经营毛竹林、集约经营毛竹林、马尾松林、农耕地、杉木林和早竹林;(3)土壤有机碳储量随土层深度变化的趋势和土壤有机碳含量变化趋势基本一致;次生林转变成长期经营的农耕地后,土壤有机碳储量下降22.5%,而转变成长期集约经营早竹林后土壤有机碳储量则下降51.4%9种土地利用类型中,土壤有机碳储量由高到低的顺序为:茶园、灌木林、次生林、粗放经营毛竹林、马尾松林、农耕地、集约经营毛竹林、杉木林和早竹林.     

蕉岭长潭省级自然保护区表土有机碳的研究

基于UTM公里网格方法划分的66个网格的土壤剖面数据,分析了蕉岭长潭自然保护区5种典型植被类型（马尾松林、杉木林、针阔混交林、阔叶混交林和竹林）的表层土壤（0～20 cm）有机碳含量、密度、储量的分布特征与影响因子。结果表明：（1）表土有机碳含量SOC分布在12.61～66.19 g·kg^-1之间,平均值为30.87±1.30 g·kg^-1,大小顺序为竹林〉阔叶混交林〉针阔混交林〉杉木林〉马尾松林,多重比较显示竹林（37.63 g·kg^-1）显著高于马尾松林（18.52 g·kg^-1）,马尾松林仅为竹林的49.21%。（2）表土有机碳密度SOCD在3.27～15.69 kg·m^-2间,平均值为8.22±0.39 kg·m^-2,大小排序为阔叶混交林〉竹林〉针阔混交林〉杉木林〉马尾松林,阔叶混交林（10.15 kg·m^-2）和竹林（9.96 kg·m^-2）的SOCD值显著高于马尾松林（4.82 kg·m^-2）（p=0.005,p=0.036）,马尾松林仅是阔叶混交林的47.49%。（3）蕉岭长潭保护区表土层有机碳储量为402 100 t,占总面积54.54%的针阔混交林贡献最大,其次为阔叶混交林、杉木林、竹林和马尾松林。（4）表土有机碳含量与土壤全氮、速效钾含量显著正相关,相关系数分别为0.40和0.31;与石砾含量极显著负相关,相关系数达到-0.76。与林下植物分布有密切联系,有机碳含量〈20 g·kg^-1的指示种有6种,包括千年桐、黄毛楤木、米碎花、谷木冬青、长叶冻绿和乌韭,有机碳含量〉40 g·kg^-1的指示种有光叶海桐和土茯苓,有机碳含量在20～40 g·kg^-1间还未发现指示种。     

长白山典型森林土壤黑碳含量及不同组分中的分布特征

[目的]通过实地采样对黑碳进行量化研究。[方法]利用相对密度分组方法探讨了长白山典型森林土壤黑碳含量及在不同有机碳组分中的分布特征。[结果]表明:黑碳(BC)含量在表层(A₁₁)、亚表层(A₁₂)分别为6.39~16.55 g·kg^-1、1.44~6.16 g·kg^-1,随土壤深度的增加而显著下降(p﹤0.01)。在A₁₁、A₁₂层中,轻组有机碳(LFOC)平均含量分别为66.66 g·kg^-1、6.65 g·kg^-1,轻组黑碳(LFBC)平均含量分别为5.63 g·kg^-1、1.21 g·kg^-1,同时,LFBC/LFOC在A₁₂层(10.02%~34.89%)显著高于A₁₁层(6.99%~14.45%)(p﹤0.01);A₁₁、A₁₂层重组有机碳(HFOC)平均含量分别为49.16 g·kg^-1、36.55 g·kg^-1,重组黑碳(HFBC)平均含量分别为2.69 g·kg^-1、1.44 g·kg^-1,HFBC/HFOC在A₁₁层(3.36%~8.08%)和A₁₂层(3.21%~7.58%)之间没有显著差异(p>0.05)。另外,土壤中LFBC/LFOC显著高于HFBC/HFOC(p﹤0.01),LFBC/BC显著高于HFBC/BC(p﹤0.01)。[结论]长白山典型森林土壤中黑碳的含量、比例均较高;土壤表层(A₁₁)有机碳、黑碳含量及各组分有机碳、黑碳含量均高于亚表层(A₁₂),均随着土层加深而显著降低;轻组、重组有机碳中均含有一定比例的黑碳,黑碳主要分布在轻组分中;轻组、重组有机碳与组分中黑碳均显著相关,轻组中相关系数大于重组。     

四川森林土壤有机碳储量估算方法选择

土壤碳是陆地碳库的重要成分,森林土壤有机碳储量的变化对全球气候变化产生重要影响。对森林土壤有机碳储量的正确估计是编制2005年IPCC国家温室气体清单的重要任务之一,也是其中的难点。本文简要介绍了森林土壤有机碳储量的各种估算方法并对各自的优缺点做了进一步的分析,指出了不确定性产生的主要原因。在分析了四川森林土壤的基本特征后,从满足编制IPCC温室气体清单高层次的方法上考虑,指出四川森林土壤有机碳储量估算的合理方法是土壤类法和生命带法相结合的办法。     

Soil organic C as affected by silvicultural and exploitative interventions in Nothofagus pumilio forests of the Chilean Patagonia

This study evaluates the effect of silvicultural and exploitative interventions on soil organic carbon (SOC) in Chilean Lenga (Nothofagus pumilio (Poepp et Endl.) Krasser) forests in south Patagonia. We analyzed SOC and the organic soil horizons in five stands at different stages of development: intact native forest (NI); a 3-year-old shelterwood stand (S3); an 8-year-old shelterwood stand (S8); a 14-year-old stand that was initially treated with shelterwood and subsequently final cut (10 years after the first intervention) (S14), and a 25-year-old stand subject to a exploitative intervention (E25). The SOC under the forest stands, down to a depth of 50 cm (including the Oi horizon), was 60, 55, 71, 85, and 67 Mg ha⁻¹ for the NI, S3, S8, S14, and E25 forest stands, respectively. A significant decrease in SOC occurred 3 years after an intensive shelterwood cut (S3), particularly in the first 5 cm of the mineral soil. Slightly higher carbon contents were observed in the upper horizons of the mineral soil in both the S8 and S14 stands. Consequently, the applied shelterwood system appears to generate only short-term losses of SOC in the Lenga forest. Soil organic carbon increased over the medium term but decreased to the level observed in intact native forests over the long term. Regeneration, which influences stand microclimate (a factor in SOC storage) and provides an important source of organic soil material, was identified as one of the most important factors influencing SOC.     

High organic carbon stock in a karstic soil of the Middle-European Forest Province persists after centuries-long agroforestry management

Little is known on soil organic carbon (SOC) stocks in karst areas worldwide, although many of them have seen long-term application of agroforestry systems with a potential for carbon sequestration. Therefore, our study aimed to assess landscape-level SOC concentration and stock in the Silica Plateau, a part of the Slovak Karst Biosphere Reserve located in the Western Carpathians (Slovakia) with a centuries-long agroforestry record. The most represented local soil units are Chromi-Rendzic Leptosols and Chromic Cambisols with clayey loam texture, C/N ratio 9–12, and $ {\text{pH}}_{{{\text{H}}_{2} {\text{O}}}} $ 6.6–6.2 in their organo-mineral surface horizons. Mull surface humus form prevails under mixed forest stands dominated by hornbeam (Carpinus betulus L.), oak (Quercus petraea L.), and beech (Fagus sylvatica L.). A total of 2,700 soil samples were collected from 150 soil pits. Both SOC concentrations and stocks were determined for the 0–60?cm mineral soil layer. Soil stoniness was accounted for by means of electrical resistivity tomography. According to the analysis of covariance, cropland SOC concentration (0.026?g?g^?1) is significantly lower compared to forestland (0.040?g?g^?1) and pastureland (0.041?g?g^?1) (P?<?0.01). During the period of 130?years after forest clearing, cropland SOC stock has been reduced at an exponential decay rate of ca 0.002?year^?1, while the SOC stock in pastureland has increased following land use change from cropland by approximately 30% during the same period of time. Irrespective of land use history, overall SOC stock is high reaching on average 207.4?Mg?ha^?1, out of which 66% are stored within 0–30?cm and 34% within 30–60?cm soil layers.     

广州白云山9种林分光合固碳放氧价值核算

采用收获法计算了广州白云山林分改造后9种新建林分的生物量,并在此基础上评估了这些林分的光合固碳和放氧价值。各种林分的光合固碳和放氧的总价值分别为:木荷851 477.17 USD/hm2,石栎244 597.27 USD/hm2,大叶相思603 695.00 USD/hm2,马占相思372 768.99 USD/hm2,藜蒴289 537.77USD/hm2,中华锥437 500.48 USD/hm2,降真香109 758.10 USD/hm2,尖叶杜英146 324.94 USD/hm2,加勒比松138 039.68 USD/hm2。以木荷和大叶相思的光合固碳和放氧价值最高。