旱作区土壤有机碳密度空间分布特征与其驱动力分析

Analysis on Spatial Distribution Characteristics and Driving Forces of Soil Organic Carbon Density in Dry Farming Region

摘要:

为直观显示0~40cm深度不同层次的土壤有机碳密度空间分布特征，并深入分析不同空间位置上有机碳密度的主要影响因素，根据2017年分层采样点的测试数据计算了旱作区土壤有机碳密度，采用反距离加权法模拟了有机碳密度空间三维分布特征，用地理加权回归分析了有机碳密度的影响因素。结果表明：旱作区土壤有机碳密度呈东北高、西南低的趋势；不同类型土壤的有机碳密度差别较大。气候（温度、降水）是旱作区有机碳密度的主要影响因素。随着土层深度的增加，气候和黏粒含量对土壤有机碳密度的解释度呈增大的趋势。年平均气温与土壤有机碳密度呈负相关性，在不同区域不同深度土层中，年降水量与土壤有机碳密度的回归系数都低于0.01，相关性很小，黏粒含量与土壤有机碳密度呈正相关性。研究成果可为探究有机碳储量估算和科学制定固碳减排政策提供数据和理论支撑。

Abstract:

It is of great importance to intuitively exhibit the spatial distribution characteristics of soil organic carbon density (SOCD) in range of 0~40cm soil depth and analyze the main influencing factors of organic SOCD. SOCD in dry farming region was calculated based on the sampling points obtained in 2017. The spatial threedimensional distribution characteristics of SOCD was simulated by inverse distance weighting method, and the influencing factors of SOCD was analyzed with the help of geographical weighted regression. The results showed that the SOCD in northeast was higher than that of southwest, and SOCD in different types of soil had large difference. Climate was the major influencing factor on SCOD in dry cropping areas. Moreover, climate and clay content had upward tendency to SOCD with the increase of soil depth. Annual average temperature had negative correlation with SOCD. It can be seen from the space that the regression coefficient was the highest in the northeast dry farming region of Heilongjiang Province, followed by Jilin and Liaoning Provinces in the central region of Heilongjiang Province and low in North China in all subregions, the regression coefficient of precipitation and SOCD was lower than 001, and the correlation was very small. The clay content was positively correlated with SOCD. The research results could provide effective support for estimating of organic carbon reserves and promoting carbon sequestration and emission reduction policies in the future.