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1.
Climate change and elevated atmospheric CO2 should affect the dynamics of soil organic carbon (SOC). SOC dynamics under uncertain patterns of climate warming and elevated atmospheric CO2 as well as with different soil erosion extents at Nelson Farm during 1998-2100 were simulated using stochastic modelling. Results based on numerous simulations showed that SOC decreased with elevated atmospheric temperature but increased with atmospheric CO2 concentration. Therefore, there was a counteract effect on SOC dynamics between climate warming and elevated CO2 . For different soil erosion extents, warming 1 C and elevated atmospheric CO2 resulted in SOC increase at least 15%, while warming 5 C and elevated CO2 resulted in SOC decrease more than 29%. SOC predictions with uncertainty assessment were conducted for different scenarios of soil erosion, climate change, and elevated CO2 . Statistically, SOC decreased linearly with the probability. SOC also decreased with time and the degree of soil erosion. For example, in 2100 with a probability of 50%, SOC was 1 617, 1 167, and 892 g m 2 , respectively, for no, minimum, and maximum soil erosion. Under climate warming 5 C and elevated CO2 , the soil carbon pools became a carbon source to the atmosphere (P > 95%). The results suggested that stochastic modelling could be a useful tool to predict future SOC dynamics under uncertain climate change and elevated CO2 .  相似文献   

2.
Effect of vegetation changes on soil erosion on the loess plateau   总被引:48,自引:0,他引:48  
ZHENG Fen-Li 《土壤圈》2006,16(4):420-427
Vegetation is one of the key factors affecting soil erosion on the Loess Plateau. The effects of vegetation destruction and vegetation restoration on soil erosion were quantified using data from long-term field runoff plots established on the eastern slope of the Ziwuling secondary forest region, China and a field survey. The results showed that before the secondary vegetation restoration period (before about 1866-1872), soil erosion in the Ziwuling region of the Loess Plateau was similar to the current erosion conditions in neighboring regions, where the soil erosion rate now is 8 000 to 10 000 t km^-2 year^-1. After the secondary vegetation restoration, soil erosion was very low; influences of rainfall and slope gradient on soil erosion were small; the vegetation effect on soil erosion was predominant; shallow gully and gully erosion ceased; and sediment deposition occurred in shallow gully and gully channels. In modern times when human activities destroyed secondary forests, soil erosion increased markedly, and erosion rates in the deforested lands reached 10 000 to 24000 t km^-2 year^-1, which was 797 to 1682 times greater than those in the forested land prior to deforestation. Rainfall intensity and landform greatly affected the soil erosion process after deforestation. These results showed that accelerated erosion caused by vegetation destruction played a key role in soil degradation and eco-environmental deterioration in deforested regions.  相似文献   

3.
基于土壤剖面测定数据计算中国土壤有机碳贮量   总被引:10,自引:0,他引:10  
Soil organic carbon (SOC) storage under different types of vegetations in China were estimated using measured data of 2 440 soil profiles to compare SOC density distribution between different estimates, to map the soil organic carbon stocks under different types of vegetation in China, and to analyze the relationships between soil organic carbon stocks and environmental variables using stepwise regression analyses. Soil organic carbon storage in China was estimated at 69.38 Gt (1015 g). There was a big difference in SOC densities for various vegetation types, with SOC distribution closely related to climatic patterns in general. Stepwise regression analyses of SOC against environmental variables showed that SOC generally increased with increasing precipitation and elevation, while it decreased with increasing temperature. Furthermore, the important factor controlling SOC accumulation for forests was elevation, while for temperate steppes mean annual temperature dominated. The more specific the vegetation type used in the regression analysis, the greater was the effect of environmental variables on SOC. However, compared to native vegetation, cultivation activities in the croplands reduced the influence of environmental variables on SOC.  相似文献   

4.
土壤有机碳活性组分沿中国长白山海拔坡度的分布情况   总被引:4,自引:0,他引:4  
Understanding the responses of soil organic carbon(SOC) fractions to altitudinal gradient variation is important for understanding changes in the carbon balance of forest ecosystems.In our study the SOC and its fractions of readily oxidizable carbon(ROC),water-soluble carbon(WSC) and microbial biomass carbon(MBC) in the soil organic and mineral horizons were investigated for four typical forest types,including mixed coniferous broad-leaved forest(MCB),dark coniferous spruce-fir forest(DCSF),dark coniferous spruce forest(DCS),and Ermans birch forest(EB),along an altitudinal gradient in the Changbai Mountain Nature Reserve in Northeast China.The results showed that there was no obvious altitudinal pattern in the SOC.Similar variation trends of SOC with altitude were observed between the organic and mineral horizons.Significant differences in the contents of SOC,WSC,MBC and ROC were found among the four forest types and between horizons.The contents of ROC in the mineral horizon,WSC in the organic horizon and MBC in both horizons in the MCB and EB forests were significantly greater than those in either DCSF or DCS forest.The proportion of soil WSC to SOC was the lowest among the three main fractions.The contents of WSC,MBC and ROC were significantly correlated(P < 0.05) with SOC content.It can be concluded that vegetation types and climate were crucial factors in regulating the distribution of soil organic carbon fractions in Changbai Mountain.  相似文献   

5.
黄土高原风蚀水蚀交错带沟岸对柠条林地土壤水分的影响   总被引:12,自引:0,他引:12  
HUO Zhu  SHAO Ming-An  R. HORTON 《土壤圈》2008,18(5):674-680
The most serious erosion on the Loess Plateau of China exists in the wind-water erosion crisscross region where the annual precipitation is about 400 mm, the ecological environment is very fragile, and water is the key limiting factor for improving the environment. In this study, changes of soil moisture content for Caragana korshinskii Kom. shrubland in the gully bank of the Loess Plateau were studied using the methods of soil sampling and neutron probe. A typical gully (75 m long, 28 m wide, and 10 m deep) was selected, and six neutron probe access tubes (6 m long) were installed at points 50, 100, 200, 300, 400, and 500 cm from the gully border for obtaining soil moisture data from July to October 2004 at approximately 10 d intervals. Soil samplings were simultaneously carried out for moisture determination at the six points. Results showed that the soil moisture of the shrubland in the gully bank significantly varied between 300 and 400 cm in the horizontal direction and up to 600 cm in vertical direction of the gully. Seasonal changes in soil moisture revealed a curve with a single peak that occurred at the end of August or early September. A linear regression equation was fit for soil water storage and the distance from the gully border, with coefficients depending on rainfall characteristics, sampling point, and time of measurement.  相似文献   

6.
Regeneration of degraded grassland ecosystems is a significant issue in restoration ecology globally. To understand the effects of artificial management measures on alpine meadows, we surveyed topsoil properties including moisture, organic carbon (SOC), nitrogen (N), and phosphorus (P) contents five years after fencing and fencing + reseeding management practices in a sandy meadow in the eastern Qinghai-Tibetan Plateau, northwestern China. Both the fencing and fencing + reseeding management practices significantly increased soil moisture storage, SOC, total N, available N, total P, and available P, as compared to the unmanaged control. Fencing plus reseeding was more effective than fencing alone for improving soil C, N, and P contents. These suggested that rehabilitation by reseeding and fencing generally had favorable effects on the soil properties in degraded sandy alpine meadows, and was an effective approach for restoration of degraded meadow ecosystems of the Qinghai-Tibetan Plateau.  相似文献   

7.
To show the vegetation succession interaction with soil properties, microbial biomass, basal respiration, and enzyme activities in different soil layers (0--60 cm) were determined in six lands, i.e., 2-, 7-, 11-, 20-, 43-year-old abandoned lands and one native grassland, in a semiarid hilly area of the Loess Plateau. The results indicated that the successional time and soil depths affected soil microbiological parameters significantly. In 20-cm soil layer, microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), MBC/MBN, MBC to soil organic carbon ratio (MBC/SOC), and soil basal respiration tended to increase with successional stages but decrease with soil depths. In contrast, metabolic quotient (qCO2) tended to decrease with successional stages but increase with soil depths. In addition, the activities of urease, catalase, neutral phosphatase, β-fructofuranosidase, and carboxymethyl cellulose (CMC) enzyme increased with successional stages and soil depths. They were significantly positively correlated with microbial biomass and SOC (P < 0.05), whereas no obvious trend was observed for the polyphenoloxidase activity. The results indicated that natural vegetation succession could improve soil quality and promote ecosystem restoration, but it needed a long time under local climate conditions.  相似文献   

8.
人工林代替天然林后土壤碳库的变化   总被引:27,自引:8,他引:19  
Changes in soil carbon pools under Chinese fir (Cunninghamia lanceolata) and bamboo (Phyllostachys pubescent) plantations substituted for a native forest (Quercus acutissima, Cyclobalanopsis glauca, Cas-tanops~.s sclerophyUa, Platycarya strobilacea, Lithocarpus glaber) were studied on the hills with acid parent rock and soils classified as red soils (Ferrisols) in Huzhou, Zhejiang Province of east China. It was found that total soil organic carbon (TSOC), easily oxidisable carbon (EOC) and water-soluble organic carbon(WSOC) under bamboo plantation were increased, but microbial biomass carbon (MBC) was decreased. On the contrary, Chinese fir induced declines of all fractions of C including TSOC, EOC, WSOC and MBC.The percentages of the active fractions of soil C (EOC and WSOC) were increased in the plantations as compared to the native broad-leaved forest, but proportions of soil organic C as MBC were decreased. It could be concluded that bamboo plantation had a great ability of not only fixing C but also accelerating soil C pool cycle, improving nutrient and microorganism activity; therefore, it is a good ecosystem and could be recommended for wide development. Chinese fir would shrink the soil C pool and deteriorate sou biological fertility, so it did not benefit CO2 fixing and land sustainable utilization.  相似文献   

9.
Soil organic carbon(SOC) content and its stable carbon isotopic composition(within the upper 1 m) were measured to determine the e?ect of land-use changes from dry evergreen forest to maize fields in eastern Thailand.Digital land cover maps,derived from aerial photography and satellite images for years 1989,1996,and 2002 were used in association with field surveys and farmer interviews to derive land-use history and to assist in study site selection.Conversion from forest to maize cultivation for the duration of 12 years reduced SOC stocks at the rate of 6.97 Mg C ha-1 year-1.Reduction was most pronounced in the top 10 cm soil layer,which was 47% after 12 years of cultivation.Stable carbon isotope data revealed that the main fraction lost was forest-derived C.Generally low input rates of maize-derived C were not sufficient to maintain SOC at the level prior to forest conversion.After 12 years of continuous maize cultivation,the maize-derived C fraction made up about 20% of total SOC(5 Mg ha-1 of the total 25.31 Mg ha-1).  相似文献   

10.
11.
There are variations in soil respiration across vegetation types; however, it is unclear which factors are mainly responsible for the variations. A field experiment was conducted in 2008 and 2009 in a semiarid region of China to investigate the daytime and monthly variation of soil respiration across vegetation types and to determine the factors controlling the variation. An automated portable soil carbon dioxide (CO2) flux measurement system was used to measure the soil respiration in shrubland, grassland, fallow land, and cropland during the growing periods. The results showed that the relative daytime variation amplitude of soil respiration in the fallow land and cropland was as small as that of shrubland and grassland during July, but greater than that of shrubland and grassland during August and October. A hysteresis effect for the relationship between the daytime soil respiration and daytime soil temperature was observed for all four vegetation types. There was also a hysteresis effect for the relationship between the daytime soil respiration and daytime air temperature for the grassland. Over the study period, the monthly soil respiration rates of the fallow land and cropland were statistically comparable and significantly lower than those of the shrubland and grassland, with the exception of August, during which the monthly soil respiration of the cropland was as great as that of shrubland and grassland. The factors responsible for the monthly soil respiration variation across the vegetation types differed from month to month. In general, the soil temperature and soil water content were mainly responsible in August and September; however, the root biomass predominated in July and October. The results are valuable for accurately estimating regional carbon fluxes by considering the temporal variability of the soil respiration variation across vegetation types in the Loess Plateau of China.  相似文献   

12.
黄土高原沟壑区人工植被类型对土壤水分和碳氮的影响   总被引:3,自引:1,他引:2  
以黄土高原沟壑区人工建造的典型植被油松、侧柏、刺槐、沙棘、苹果为研究对象,研究分析了不同植被类型对土壤水分含量、土壤碳氮累积等的变化影响。研究表明,旱季刺槐林地表现出了强烈的耗水特征,200cm以下土壤含水量具明显减少趋势。200—300cm处水分含量仅为5.8%~7.1%,而油松林地200cm以下与荒草地含水量基本相一致,土壤水分含量保持在15%左右,侧柏、沙棘、苹果土壤水分利用主要在20-200cm范围内。雨季,天然降雨虽对林地水分含量有所补充,但只表现在0-50cm表层,且各个植被类型间表现不明显;与荒草相比,油松群落土壤有机碳氮提高了9.3%,果园土壤有机碳含量显著降低,而沙棘、侧柏和刺槐群落的土壤有机碳含量虽低于荒草群落,但尚未达到显著水平。  相似文献   

13.
[目的]探究黄土高原植被恢复过程中土壤微生物的演变特征,为黄土高原生态恢复重建工作提供科学参考。[方法]以Web of Science数据库和CNKI数据库中的期刊论文为数据源,运用CiteSpace文献计量工具对黄土高原植被恢复过程中土壤微生物演变的研究概况及研究热点进行分析。[结果]2002—2018年黄土高原植被恢复过程中土壤微生物演变特征相关文献的发表数量随时间呈增长趋势;国内外研究热点主要围绕土壤微生物量、微生物群落结构以及酶活性展开,且对于微生物量的关注度比较高;在植被演替过程中,微生物生物量和酶活性总体增加,微生物群落从贫营养型向富营养型转变,土壤微生物群落结构和功能的进一步改善。不同植被类型对土壤生物质量改善效果不同,总体来说,混交林作用效果最好,刺槐和柠条纯林次之,荒草地和油松纯林最低。[结论]黄土高原植被恢复土壤微生物今后的研究应注重微生物关键种的识别、参与碳氮磷循环的功能微生物以及全球变化对微生物群落影响等方面。  相似文献   

14.
子午岭地区植被演替的土壤碳汇效应   总被引:2,自引:0,他引:2       下载免费PDF全文
为明确黄土高原地区植被长期恢复的土壤碳汇效应,采用时空互代的方法,研究子午岭地区150年以来8个植被演替序列的土壤有机碳含量及储量的变化特征,分析影响土壤有机碳储量变化的植被因素。结果表明:从农地演替到气候顶级辽东栎(Quercus wutaishanicaMary.)群落,土壤有机碳含量和储量明显增加,表现为演替前期(草本群落)快速增加,后期(乔木群落)趋向稳定的变化特征。剖面上来看,随着土层加深,土壤有机碳含量迅速减少。0—5 cm土层土壤有机碳含量与5—20,20—40 cm土层差异显著(P<0.05),表明土壤有机碳积累存在明显的表聚效应。枯落物蓄积量与细根生物量均随演替时间呈现出增加的变化特征,前者更有利于提高土壤有机碳储量。0—5 cm土层与0—20 cm土层土壤有机碳储量与演替时间均存在极显著的幂函数关系,不同土层之间土壤有机碳储量线性相关关系显著(P<0.001)。植被长期演替具有显著的土壤碳汇功能。未来黄土高原地区林、草地的恢复应根据植被带的分异规律,促进自然演替,以进一步提升该地区的土壤碳汇潜能。  相似文献   

15.
Experimentation with dynamics of soil carbon pools as affected by elevated CO2 can better define the ability of terrestrial ecosystems to sequester global carbon. In the present study, 6 N HCl hydrolysis and stable-carbon isotopic analysis (δ13C) were used to investigate labile and recalcitrant soil carbon pools and the translocation among these pools of sorghum residues isotopically labeled in the 1998-1999 Arizona Maricopa free air CO2 enrichment (FACE) experiment, in which elevated CO2 (FACE: 560 μmol mol−1) and ambient CO2 (Control: 360 μmol mol−1) interact with water-adequate (wet) and water-deficient (dry) treatments. We found that on average 53% of the final soil organic carbon (SOC) in the FACE plot was in the recalcitrant carbon pool and 47% in the labile pool, whereas in the Control plot 46% and 54% of carbon were in recalcitrant and labile pools, respectively, indicating that elevated CO2 transferred more SOC into the slow-decay carbon pool. Also, isotopic mixing models revealed that increased new sorghum residue input to the recalcitrant pool mainly accounts for this change, especially for the upper soil horizon (0-30 cm) where new carbon in recalcitrant soil pools of FACE wet and dry treatments was 1.7 and 2.8 times as large as that in respective Control recalcitrant pools. Similarly, old C in the recalcitrant pool under elevated CO2 was higher than that under ambient CO2, indicating that elevated CO2 reduces the decay of the old C in recalcitrant pool. Mean residence time (MRT) of bulk soil carbon at the depth of 0-30 cm was significantly longer in FACE plot than Control plot by the averages of 12 and 13 yr under the dry and wet conditions, respectively. The MRT was positively correlated to the ratio of carbon content in the recalcitrant pool to total SOC and negatively correlated to the ratio of carbon content in the labile pool to total SOC. Influence of water alone on the bulk SOC or the labile and recalcitrant pools was not significant. However, water stress interacting with CO2 enhanced the shift of the carbon from labile pool to recalcitrant pool. Our results imply that terrestrial agroecosystems may play a critical role in sequestrating atmospheric CO2 and mitigating harmful CO2 under future atmospheric conditions.  相似文献   

16.
Soil organic carbon (SOC) sequestration by vegetation restoration is the theme of much current research. Since 1999, the program of “Grain for Green”has been implemented in the semi-arid Loess Plateau, China. Its scope represents the largest vegetation restoration activity in China. However, it is still unclear for the SOC sequestration effects of vegetation cover change or natural succession promoted by the revegetation efforts at different scales under the semi-arid conditions. In this study, the changes in SOC stocks due to the vegetation restoration in the middle of Loess Plateau were estimated at patch, hill slope transect and small watershed scale from 1998 to 2006. Soil samples were taken from field for the determination of cesium-137 (137Cs) and SOC contents. Vegetation cover change from 1998 to 2006 at the small watershed scale was assessed using Geographic Information System. The results showed that cropland transforming to grassland or shrubland significantly increased SOC at patch scale. Immature woodland, however, has no significant effect. When vegetation cover has no transformation for mature woodland (25 years old), SOC has no significant increase implying that SOC has come to a stable level. At hill slope scale, three typical vegetation cover patterns showed different SOC sequestration effects of 8.6%, 24.6%, and 21.4% from 1998 to 2006, and these SOC increases mainly resulted from revegetation. At the small watershed scale, SOC stocks increased by 19% in the surface soil layer at 0–20 cm soil depth from 1998 to 2006, which was equivalent to an average SOC sequestration rate of 19.92 t C y− 1 km− 2. Meanwhile, SOC contents showed a significant positive correlation (P < 0.001) with the 137Cs inventory at every soil depth interval. This implied significant negative impacts of soil erosion on SOC sequestration. The results have demonstrated general positive effects of vegetation restoration on SOC sequestration at multiple scales. However, soil erosion under rugged topography modified the spatial distribution of the SOC sequestration effects. Therefore, vegetation restoration was proved to be a significant carbon sink, whereas, erosion could be a carbon source in high erosion sensitive regions. This research can contribute to the performance assessment of ecological rehabilitation projects such as “Grain to Green” and the scientific understanding of the impacts of vegetation restoration and soil erosion on soil carbon dynamics in semi-arid environments.  相似文献   

17.
[目的]阐明晋西黄土区典型人工植被类型对球囊霉素相关土壤蛋白(GRSP)和团聚体稳定性的影响,以及两者之间的关系,为黄土高原地区人工植被建设与管理提供科学依据。[方法]选取晋西三川河流域4种典型人工植被(苜蓿、刺槐、侧柏和核桃),以农地为对照,分析0—100cm土层中GRSP组分、有机碳(SOC)和团聚体稳定性指标在不同植被类型下的分布差异及其相关性。[结果]不同植被类型下易球囊霉素(EE-GRSP)、总球囊霉素(T-GRSP)以及两者的比值在0—30cm土层存在显著差异,均以核桃地最高,而苜蓿地较低。不同植被下EE-GRSP/SOC和T-GRSP/SOC均随着土层深度增加而增加,分别为1.78~6.77,4.07~19.11。与农地相比,侧柏和苜蓿地分别增加了39.67%,36.62%的EE-GRSP/SOC以及39.25%和46.70%的T-GRSP/SOC,而核桃分别减少了31.07%和36.93%。平均重量直径与T-GRSP和SOC呈显著正相关关系,而与EE-GRSP/SOC呈显著负相关关系(p0.05)。[结论]不同人工植被对表层土壤GRSP的组分有明显影响,土壤团聚体稳定性不仅与GRSP的组分有关,也与其对SOC的贡献有重要关系。  相似文献   

18.
为明确在干旱缺水地区,植被对深层土壤水分的过度消耗以及水资源的承载能力,在晋西黄土残塬沟壑区选取林分密度1 300株/hm~2的刺槐人工林为研究对象,以裸地为对照,利用Enviro-SMART土壤水分监测系统(FDR)和热扩散探针(TDP)技术对当地刺槐人工林地0—150 cm范围内各土层体积含水量与树干液流量进行长期连续定位观测,采用土壤有效水与单株刺槐耗水量的比值来衡量研究区刺槐人工林土壤水分植被承载力。结果表明:(1)月降水量和月土壤储水量是决定刺槐人工林土壤水分植被承载力的主要环境因子,且二者与土壤水分植被承载力之间均呈现显著的正比例关系(P0.05)。(2)根据构建的刺槐人工林土壤水分植被承载力模型,计算出当地林龄为19年的刺槐人工林0—150 cm土层深度的土壤水分植被承载力为1 224株/hm~2,稍小于研究区实际林分密度(1 300株/hm~2),为保证当地刺槐人工林分耗水深度控制在0—150 cm土层范围内,同时也为促进当地林分生产力处于最优水平,建议在今后的营林造林过程中将刺槐人工林密度控制在当地土壤水分植被承载力范围之内,在减少林地深层水分消耗、调整林地土壤水资源平衡的同时,促进当地林业产业的合理发展。  相似文献   

19.
以甘南尕海4种不同退化程度的湿地(未退化(UD)、轻度退化(LD)、中度退化(MD)及重度退化(HD))为研究对象,采用室内5 ℃、15 ℃、25 ℃、35 ℃ 培养法,测定不同土层 SOC 矿化速率和累积矿化量,运用一级动力学方程对土壤的半矿化分解时间(T1/2)、有机碳矿化潜势(C0)等参数进行拟合,分析温度、土壤深度和退化程度对土壤碳矿化过程的影响。结果表明:(1)在不同土层、不同温度下,各植被退化程度湿地土壤有机碳 CO2 释放量在整个培养期间大致可以分三个阶段,0-4 d快速生成 CO2 阶段,4-27 d缓慢生成 CO2 阶段,27-41 d平稳阶段;0-10 cm 土层各培养温度下,土壤有机碳矿化速率表现为UD>LD>MD>HD。(2)培养期间,不同退化湿地土壤有机碳矿化速率均随土层加深而降低,表层 0-10 cm的矿化速率(1.14~16.23 mg/(g?d))均显著高于10-20 cm(1.05~2.85 mg/(g?d))和20-40 cm(0.94~1.26 mg/(g?d))土层。(3)整个培养期内,不同退化湿地土壤有机碳总累积矿化量排序为5 ℃(34.54 mg/g)、15 ℃(46.67 mg/g)、25 ℃(58.28 mg/g)和35 ℃(86.46 mg/g)。(4)双库一级动力学方程的C0值随退化程度增加呈递减趋势,而C0/SOC随着温度的升高而降低。  相似文献   

20.
本研究选择陕北黄土高原绥德、吴旗、宜川3个地区,调查分析了不同植被恢复类型(草、灌、乔)下05cm表层土壤水稳性团聚体粒径分布及其有机碳含量的变化。结果表明:不同植被恢复类型均显著提高了 2mm和2~0.25mm 两个粒级的水稳性团聚体及其有机碳(SOC)的含量,但不同植被恢复类型的作用在3个地区有所不同。与农地相比,在绥德,油松和柠条、分别使 2mm和2~0.25mm粒级的水稳性团聚体中的SOC含量分别提高了99%~153%和219%~350% ,但苜蓿没有明显作用;在吴旗,苜蓿、沙棘、刺槐分别使 2mm和2~0.25mm水稳性团聚体中SOC含量分别提高了28%~30%和85%~130%,而刺槐对 2mm水稳性团聚体没有作用,而使2~0.25mm粒级的水稳性团聚体SOC含量提高了210% ; 在宜川,白草、羊胡草、狼牙刺和油松使 2mm和2~0.25mm粒级的水稳性团聚体中的SOC含量分别提高了405%~932%和724%~1130%。植被恢复土壤增碳主要是提高了2~0.25mm和2mm 两个粒级的水稳性团聚体中SOC的含量,提高值分别为514%和470%,占土壤有机碳库增量的49%和43%,而对其它粒级水稳性团聚体中SOC含量的贡献小于16%。以上研究结果说明,植被恢复稳定土层结构、促进土壤水稳性大团聚体中SOC的形成,可能在黄土丘陵侵蚀景观土壤固碳过程中起重要作用。  相似文献   

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