土壤容重数据的不确定性对有机碳密度估算的影响  

The Influence of the Uncertainty Caused by Soil Bulk Density on Soil-Organic-Carbon-Density Calculation

作　　者：李秀芝[1] 胡聪月 王德彩[2] 韩光中[1] LI Xiuzhi;HU Congyue;WANG Decai;HAN Guangzhong(College of Geography and Resources Science,Neijiang Normal University,Neijiang 641112,Sichuan;College of Forestry,Henan Agricultural University,Zhengzhou,450002,Henan)

机构地区：[1]内江师范学院地理与资源科学学院,四川内江641112 [2]河南农业大学林学院,河南郑州450002

出　　处：《四川师范大学学报（自然科学版）》2022年第6期800-805,共6页Journal of Sichuan Normal University（Natural Science）

基　　金：国家级大学生创新创业训练计划(X2018015);内江市社科规划项目(Z015014)。

摘　　要：土壤容重是土壤有机碳密度(SOCD)估算模型中的一个必要参数,但当前的研究很少关注其对SOCD估算的影响.通过收集和整理中国第二次土壤普查资料、中国土壤系统分类资料和典型区土壤样本资料,系统讨论土壤容重数据的不确定性对SOCD估算的影响.我国土壤容重数据的不确定性主要来源于两个方面:一些非土壤性物质导致的细土容重测定结果的偏差;已有土壤数据库土壤容重数据的缺失.通常砾石会高估细土容重,根系会低估细土容重,其高估率或低估率与其质量分数和体积分数呈极显著正相关.当土壤中的砾石和根系较多时,传统的估算方法均会高估SOCD,高估率分别介于-1.5%~45.5%和2.4%~8.5%.可根据砾石或根系的含量,利用公式对容重数据进行换算,提高SOCD的估算精度.当土壤容重数据缺失时,利用土壤容重传递函数预测土壤容重能明显提高SOCD的估算精度.Soil bulk density is one of most important physical properties of soil and is an essential parameter in soil-organic-carbon-density(SOCD)calculation.Unfortunately,there are some uncertainties in the estimation and determination of soil bulk density in China,which is not conducive to accurately evaluating the density or storage of soil organic carbon on a regional or national scale.In this study,we collected soil data for major types of soils in China from the Second National Soil Survey of China,the database for the Chinese Soil Taxonomy and soil survey data of typical areas in order to explore the uncertainty of soil bulk density and its influence on SOCD calculations.The uncertainty of soil bulk density in China mainly comes from the following two aspects:first,a serious lack of bulk density data in the existing soil database;secondly,the measurement deviation caused by some non-soil substances,such as gravel and root.Soil bulk density of fine soil fractions were usually overestimated or underestimated depending on the contents of gravel or root and its over/under-estimation rate is significantly positively correlated with its weight percentage and volume percentage.The missing soil bulk density predicted from PTFs or the emendation of soil bulk density by introducing correction parameters proposed in this paper to isolate the effect of gravel or root significantly improved the performance of SOCD models.

关 键 词：土壤容重 不确定性 有机碳密度 砾石 根系 

分 类 号：S159.2[农业科学—土壤学]