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1.
中国陆地土壤有机碳储量估算及其不确定性分析   总被引:3,自引:0,他引:3  
土壤有机碳密度和储量的统计对于研究土壤碳循环至关重要.为提高土壤有机碳密度和储量的估算精度,明晰导致估算存在不确定性的内在原因,根据第二次土壤普查资料,采用两种方式、两种土层厚度、两个公式以及3种碳密度取值方法估算了中国土壤有机碳储量,结果表明,中国陆地土壤有机碳储量大致在50.6~154.0 Pg(1 Pg=1015 g)之间,平均储量为(102.3±51.7)Pg;估算的不确定性处于25.5%~30.4%之间.中国陆地土壤有机碳储量估算结果差异以及不确定性主要来源于以下几个方面:碳密度的取值方法不同,估算深度不一致,计算公式不统一,基础数据不一样以及制图尺度差异.本文研究结果认为基于GIS数字土壤图,采用标准1 m厚度土层,运用不考虑大于2 mm砾石含量的碳密度计算公式以及分土层累计计算法是估算中国陆地土壤有机碳储量最优方法.  相似文献   

2.
区域土壤有机碳密度及碳储量计算方法探讨   总被引:20,自引:1,他引:19  
土体中有机碳含量在纵向和横向上都具有空间相关性。本文利用曲周县四疃乡30个土壤剖面的有机碳含量数据,采用常见的纵向拟合方法建立了基于30个土壤剖面有机碳测定数据的对数函数拟合模型,计算得到研究区的土壤有机碳密度和碳储量分别为5.60kg C m-2和4.72×108kgC;又根据研究区土壤剖面中有机碳含量分布的不规则性特点,通过对土壤剖面层次的归一化处理,利用地统计横向插值方法,计算得到该区的土壤有机碳密度和碳储量分别为3.95kg Cm-2和3.33×108kgC。由于两种算法对数据的组织方式不同,得到的土壤有机碳密度和碳储量存在较大差异。两种方法适用于土壤有机碳在剖面中分布形式不同的土壤类型。  相似文献   

3.
青藏高原土壤有机碳储量与密度分布   总被引:13,自引:0,他引:13       下载免费PDF全文
采用全国第二次土壤普查数据结合作者的实测数据,利用1∶100万土壤数据库对青藏高原土壤有机质层、土壤矿质层及整个剖面的土壤有机碳密度和土壤有机碳储量分别进行了估算。结果表明:青藏高原的平均土壤有机碳密度约为C 7.2 kg m-2,较前人的C 8.01~19.05 kg m-2全国平均土壤有机碳密度偏低。青藏高原总的土壤有机碳储量约为18.37 Pg,其中有机质层土壤有机碳储量约占38.14%,矿质层土壤有机碳储量则占61.86%。  相似文献   

4.
浅谈土壤有机碳密度及储量的估算方法   总被引:19,自引:2,他引:17  
土壤有机碳储量、分布在陆地碳循环中起着重要的作用。本文阐明了土壤有机碳密度及储量的重要意义,主要介绍了国内外几种重要的有关土壤有机碳储量的估算方法及其优缺点,为全面而细致准确地估算我国土壤有机碳储量提供了可能途径。  相似文献   

5.
[目的]研究三江平原2010年表层(0—30cm)土壤有机碳储量空间分布规律和不同土地利用类型对有机碳空间分布的影响。[方法]采用地统计学和GIS相结合的方法。[结果](1)2010年三江平原表层土壤有机碳总储量为1161.28Tg;(2)表层土壤有机碳空间分布变异性较大,中部和西南地区较低,东北、西北、东南地区较高;(3)不同土地利用类型土壤有机碳密度和储量有所不同,旱地表层土壤有机碳储量最大,为412.10Tg,草地最小,表层土壤有机碳储量为2.31Tg;(4)不同植被类型表层土壤有机碳密度大小顺序为:沼泽湿地林地草地水田旱地,沼泽湿地表层土壤有机碳密度为147.84Mg/hm2。[结论]三江平原土壤有机碳密度空间分布存在较大的分异性,土壤有机碳密度的空间分布特征受土地利用类型分布的影响。  相似文献   

6.
江苏表层土壤有机碳密度和储量估算和空间分布分析   总被引:22,自引:2,他引:20  
基于1:50万的江苏土壤图和江苏土壤的数据,运用地理信息系统技术,对江苏表层土壤有机碳密度及储量做出估算,并且分析了土壤有机碳密度的空间分布差异。结果表明:土壤有机碳密度介于4.2kgm-2到20.32kgm-2之间,土壤有机碳储量为673892.8×106kg;土壤有机碳密度具有高度的空间变异性,兴化、南通和无锡的有机碳密度最高,沿海地区的有机碳密度比较高,最低的为淮阴及其附近地区。  相似文献   

7.
为阐明喀斯特小流域土壤有机碳密度分布特征及有机碳储量空间分布格局,采用野外布点采样、实验室测定和地统计学分析相结合的方法,利用2 755个详细调查的剖面样地和23 536个土壤样品,定量研究了喀斯特小流域土壤有机碳密度、碳储量的空间异质性及分布特征。结果表明:后寨河小流域表层(0—20cm)土壤有机碳含量和密度的平均值为分别为25.07g/kg和5.23kg/m~2,剖面土壤(0—100cm)土壤有机碳含量和有机碳密度分别为20.71g/kg和10.21kg/m~2,两层土壤有机碳含量和密度均属于中等变异强度。10cm土层深度有机碳储量为1.48×10~8 kg,20cm土层深度有机碳储量为2.65×10~8 kg,30cm土层深度土壤有机碳储量3.43×10~8 kg,100cm土层深度有机碳储量5.39×10~8 kg。各层土壤有机碳储量的块金值C_0随着土层深度的增加而增加,而0—100cm的块金值C_0最大。4种土层深度土壤有机碳储量呈现为中部低,四周高,南部最低的趋势。海拔、坡度、岩石裸露率和石砾含量是影响喀斯特小流域土壤有机碳储量空间异质性的主导因子。  相似文献   

8.
不同植被下中国土壤有机碳的储量与影响因子   总被引:79,自引:0,他引:79       下载免费PDF全文
基于第二次土壤普查和新疆土壤调查等 2 4 4 0个典型土壤剖面数据和 1∶4 0 0万中国植被图 ,对中国不同植被类型下的 1 0 0cm和 2 0cm厚度土壤有机碳密度和储量进行估算 ,绘制了土壤有机碳储量的地理分布图 ,并且对土壤有机碳储量与生境条件之间的关系进行统计分析。结果表明 :不同植被类型下的土壤有机碳密度存在显著差异 ,草甸和森林最高 ,灌木和农田次之 ,再其次是草原 ,最低的是荒漠 ;基于植被分类计算的我国 1 0 0cm和 2 0cm厚度土壤有机碳总储量分别为 6 9.38Gt和 2 3.81Gt。 1 0 0cm深度土壤碳储量在森林、农田、灌丛、草甸、草原、荒漠植被下分别为 1 7.39Gt、1 4 .6 9Gt、1 3.6 2Gt、1 2 .2 2Gt、7.4 6Gt、3.93Gt;土壤有机碳储量的空间分布差异明显 ,具有明显地域性 ,青藏高原东南地区、阿尔泰山和天山山地等高寒草甸、灌丛草甸区是土壤有机碳储量最高的地区 ,其次是东北地区北部的针叶林、草甸区和我国南方的亚热带阔叶林区 ,土壤有机碳储量最低的地区是西北地区和藏北高原的荒漠、草原干旱区 ;在不同生态系统中环境变量对土壤有机碳储量的影响是不同的 ,在温带草原年平均温度是土壤有机碳储量主要控制因素 ,而对于针叶林海拔是导致土壤有机碳储量变异的主导因子 ;随着研究尺度的细化 ,环境变  相似文献   

9.
《土壤通报》2015,(4):774-780
运用GIS和地统计学相结合的方法,通过对全国第二次土壤普查时期(1980年)、2000年、2011年研究区三期采样数据的比较,研究了东北主要黑土区海伦、双城、公主岭三个县(市)不同时期的土壤有机碳密度与储量,并分析了30年来研究区土壤有机碳密度与储量在时间与空间的变化情况。研究表明:海伦、双城和公主岭过去30年间土壤有机碳密度分别下降了0.68 kg m-2、0.18 kg m-2和1.05 kg m-2;储量分别下降了0.23×1010kg、0.05×1010kg和0.18×1010kg。海伦、双城前20年有机碳密度下降速率较快,后10年趋向平稳并略微增长,公主岭有机碳密度在研究期的30年内仍处于快速下降阶段。按照土类统计,1980年与2011年两个时期研究区的有机碳密度与储量,结果表明几乎所有土壤类型的有机碳密度与储量均出现下降,有机碳密度降幅最大的为棕壤(下降1.95 kg m-2),有机碳储量降幅最大为黑土(下降0.29×1010kg)。  相似文献   

10.
上海市绿地表层土壤有机碳储量的估算   总被引:1,自引:0,他引:1  
张青青  伍海兵  梁晶 《土壤》2020,52(4):819-824
本文调查了上海市472个绿地土壤样点,通过对其土壤有机碳含量、密度等指标进行测定分析,最终估算出上海市绿地土壤表层有机碳储量,同时为预测上海市未来十几年的碳库变化提供数据支撑。研究结果表明:①上海市绿地表层(0~20 cm)土壤有机碳空间分异性较大,土壤有机碳含量和密度表现为西高东低,且自中心向四周逐渐增高。②不同绿地类型土壤有机碳含量大小依次为:公园绿地公共绿地道路绿地;有机碳密度的大小依次为:公共绿地公园绿地道路绿地。不同绿地类型土壤有机碳含量和密度差异显著,其中,城区不同绿地类型土壤有机碳含量和密度差异显著(P0.05),但郊区不同绿地类型土壤有机碳含量和密度差异不显著(P0.05)。③2015年上海市绿地表层土壤有机碳储量约为4.26×106 t。预计到2035年,上海市绿地表层土壤有机碳储量约可达到1.53×107 t。  相似文献   

11.
A decrease in the depth of organic surface horizons (forest litters and steppe mats), the reserves of organic matter in them, and an increase in their renewal rate were noted for virgin and fallow soils when going from the southern taiga to the dry steppe zone. Zonal changes in the content and reserve of easily decomposable soil organic matter showed a similar tendency: these parameters regularly decreased from soddy-podzolic soils of the southern taiga to chestnut and light chestnut soils of the dry steppe. An exception from this series is provided by fallow chernozems of the steppe zone noted for the lowest content and reserve of labile organic matter in the series of soils studied. Similar, although less pronounced, tendencies were observed for the arable soils.  相似文献   

12.
DETERMINATION OF ORGANIC CARBON IN SOIL   总被引:1,自引:0,他引:1  
The organic carbon contents of a range of soils and of various organic materials (mostly of plant origin) were determined by the titrimetric methods of Tinsley and Walkley and Black, and the results compared with those obtained by Shaw's wet combustion method. Tinsley's method gave more reliable results with soils than Walkley and Black's method, but neither is satisfactory for precise work. Both give high results with organic materials less oxidized than elemental carbon and low results with organic materials more oxidized, although this effect is masked with materials which do not react completely under Walkley and Black conditions. Quantitative results were obtained on a range of whole plant materials with both Tinsley's and Walkley and Black's methods. The latter thus provides a very rapid method for the determination of carbon in plants. The carbon contents, determined by Tinsley's method, of a range of pure organic compounds agreed with the predicted values. Tinsley's method does not give quantitative results with certain soils, partly because of the oxidation level of the organic matter in these soils and partly because oxidation is incomplete.  相似文献   

13.
在紫色丘陵区采集了因水分状况影响而形成的4种类型紫色水稻土土样,利用湿筛法获得不同粒径的团聚体,分析了其有机碳和不同土壤发生层中易氧化碳、微生物生物量碳和水溶性碳含量。结果表明,A层土壤中>2 mm的团聚体以潜育型水稻土和渗育型水稻土最高,分别占76.65%和75.92%,其次是潴育型水稻土占43.86%,淹育型水稻土只有13.10%;不同土壤发生层间土壤团聚体的组成也存在较大的差异;除潴育型水稻土的P层外,其余各层土壤的有机碳53.7%~96.2%均分布在>0.25 mm团聚体中;潜育型水稻土的微生物生物量碳和易氧化碳含量在4种水稻土中最高,分别为282.5 mg kg-1和6.59 g kg-1,水溶性有机碳则以渗育型水稻土最高;有机碳含量与>2 mm团聚体含量呈极显著正相关关系,与<0.25 mm微团聚体数量呈显著负相关关系。  相似文献   

14.
Soils of the Arkaim Reserve were studied before the establishment of the reserve and, then, 12 and 18 years after the reservation of this territory. Former pastures and hayfields occupy 70% of the reserve, and former plowlands occupy about 30%. Some of them have been converted into sown meadows. The soil cover of the reserve is composed of chernozems (about 50% of the area), solonetzes and salt-affected soils (32%), meadow-chernozemic soils (7%), and forest soils (1%). In eighteen years of reservation, the Corg content in the upper 20 cm has increased by 0.5–0.8%, or by 14–25% of the initial content with the average rate of 60–100 g C/m2 per year. The accumulation of Corg has been more intensive in the soils of former plowlands than in the soils of former pastures and in the chernozems than in the meadow-chernozemic soils. Self-restoration of most of the soils of the reserve is accompanied the rise in the content of the labile fraction of organic carbon. In some soils, the contents of the labile fraction (0.3%) and light-weight fraction (>25% of Corg) have reached optimum values. After 18 years of reservation, the biomass of microorganisms has reached 500–800 μg/g of soil (or 1.1–1.9% of Corg); the basal respiration has reached 0.7–1.5 μg C-CO2/g per hour. These characteristics are the highest for meadow-chernozemic soils under former pasture and the lowest for postagrogenic chernozems. The rise in the Corg content and changes in the particular forms of soil organic matter under the regime of a reserve greatly depend on the soil type and on the former land use. The role of parent materials is smaller. Many soils of the reserve require a long period of rehabilitation.  相似文献   

15.
The carbon content of topsoil and its geographical distribution in France   总被引:9,自引:0,他引:9  
Abstract. An estimate of organic carbon stored in French soils to a depth of 30 cm was made using data from geo-referenced databases. We produced statistics on carbon stocks in soils according to land use, different land uses and soil type. Then, using a combination of maps of soil and land use we were able to estimate regional and national carbon stocks. This soil carbon map of France allowed us to identify the main controlling factors of the carbon distribution: land use, soil type in some cases, clay content, and elevation. Carbon stocks in French soils were found to be about 3.1 Pg (1015g).  相似文献   

16.
THE ORGANIC MATTER CONTENT OF THE SAVANNA SOILS OF WEST AFRICA   总被引:2,自引:0,他引:2  
Published and unpublished data on the amounts of organic matter and nitrogen in the surface soils of the West African savanna are reviewed. In general, amounts are small; the mean carbon content of soils from 605 well-drained sites was 0.68 per cent. Two important factors governing amounts of organic matter in well-drained soils appear to be the clay content and a moisture factor related to the length of the wet season and represented here by mean annual rainfall. Multiple linear regression on soil clay content and rainfall accounted for 46.5 per cent and 57.2 per cent, respectively, of the observed variability of soil carbon and nitrogen contents. These findings suggest that the low levels of organic matter in savanna soils arise from their predominantly sandy nature and from the relatively low rainfall. In poorly drained soils organic matter levels are higher but are less significantly related to clay content and rainfall. The influence of human interference and of parent material and altitude on organic matter is demonstrated in the context of geographically limited areas within the savanna for which more detailed information was available.  相似文献   

17.
Abstract

The influence of some soil properties on hot 0.02 M calcium chloride (CaCl2) extractable boron in the Argentine Pampas was studied. The selected soils represent an extensive area in the middle west of the country where most of the grain crops are produced. Soils have all developed on loess and cover a wide range of organic matter, pH, and exchangeable calcium. The most representative soils are Typic Argiudolls and Typic Haplustolls. Two hundred soil samples were taken in order to characterize their 0.02 M CaCl2 extractable boron content and study the boron behavior with regard to other soils properties and environmental conditions. The amounts of extracted boron on all samples had a significant correlation with soil organic carbon (positive), and soil pH (negative). The regression equation between extractable boron and organic carbon content was y=0.1021+0.3722 OC R2: 0.51. Since solubility in hot CaCl2, 0,02 M is considered an availability index, these results support the hypothesis that organic carbon content is the main boron reserve for plants. When a multiple regression was calculated, both variables organic carbon and pH explained 57% of variation in extractable boron. The studied area can be subdivided into regions with different boron content, within each region the relationship between boron content and organic carbon and pH were also different. The exchangeable calcium content had a light influence especially in the subsuperficial layer. The influence of environmental conditions on boron content and its relationship with soil properties were discussed.  相似文献   

18.
中国东部主要农田土壤有机碳库的平衡与趋势分析   总被引:43,自引:3,他引:40  
根据田间测定的有机物料腐殖化系数和土壤有机碳矿化量结果 ,以及统计测算的有机物质进入量 ,分析了中国东部主要农业区农田土壤有机碳库的平衡状况 ,并对其作为大气CO2 的源汇功能进行了初步评价。结果表明 ,各农业区农田土壤中有机物料腐殖化系数的变化趋势为 :松嫩平原 (作物秸秆 0 3 7,作物根 0 47,绿肥 0 2 6 ,粪肥 0 5 4 ) >红壤丘陵区(相应值为 0 2 8,0 45 ,0 2 5 ,0 42 ) >下辽河平原 (相应值 0 3 5 ,0 3 9,0 2 2 ,0 3 3 ) >黄淮海平原(相应值 0 2 5 ,0 3 2 ,0 1 8,0 2 7)。各区间的腐殖化系数并不随气候而呈规律性变异 ,而主要是环境因子综合作用的结果 ,特别是土壤性质有显著影响。现实有机物质进入量条件下 ,各农业区农田土壤有机碳年形成量分别为 :松嫩平原 5 3 8 0kghm- 2 ,下辽河平原 6 79 7kghm- 2 ,黄淮海平原 76 0 7kghm- 2 ,红壤丘陵区 1 0 5 9 7kghm- 2 ;农田土壤有机碳年矿化量分别为 :松嫩平原 90 5 3kghm- 2 ,下辽河平原 72 3 5kghm- 2 ,黄淮海平原 72 3 1kghm- 2 ,红壤丘陵区 782 9kghm- 2 。因此 ,松嫩平原黑土的有机碳库处于亏缺状态 ,土壤有机碳含量还将下降 ,并向大气释放CO2 ;红壤水稻土的有机碳库处于盈余状态 ,土壤有机碳含量还将不断提高 ,是大气C  相似文献   

19.
The monosaccharide composition of Ando soils, which originate from volcanic ash and have high organic matter content (8–21% carbon), was quite different from that of non-volcanic ash soils (1.2–1.9% carbon), being richer in mannose, fucose and ribose, whereas there was less glucose in cellulose-like form, arabinose, xylose and rhamnose. The Ando soils were also characterized by a lower percentage of organic carbon in the form of saccharide (4.4–7.4%) in comparison with non-volcanic ash soils (10.5%), though the former soils contain a greater amount of saccharides. The monosaccharide composition of Ando soils was unrelated to the vegetation, land usage, or climatic conditions, and is presumed to be a soil characteristic resulting from the preferential accumulation of microbial polysaccharides.  相似文献   

20.
张丹蓉  MermoudAndre  管仪庆 《土壤》2005,37(2):187-191
吸附是决定除草剂地乐酚在土壤中迁移的重要机制之一。通常用简单快捷的批实验来衡量土壤对除草剂的吸附。由大量的批实验确定地乐酚在不同土壤样本中的吸附参数,并对各土壤特性与吸附参数的相关性作统计分析。结果表明土壤有机C含量,粘粒含量及阳离子代换量与吸附参数显著正相关,土壤pH值与吸附参数显著负相关。方差分析表明地乐酚在土壤中的吸附表现出很强的空间差异,在不同地点的地乐酚吸附参数无显著区别,而在不同的深度区别显著。超过85%的地乐酚吸附参数的空间差异可由土壤有机C含量的空间差异来解释。  相似文献   

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