Proportion of pedogenic carbonates and the impact on carbon sink calculation in karst area with semiarid environment
HUANG Qi-bo
QIN Xiao-qun
LIU Peng-yu
ZHANG Lian-kai
SU Chun-tian
Abstract：Quantitative evaluation of proportion and source of pedogenic carbonates in karst area with semiar-id environment have contributed to understand the mechanism of soil system affecting karst process,which has great significance in karst carbon cycle research.Soil samples were collected from soil profile of forest land,abandoned farmland and brushland,in a typical small watershed in semi-arid area,southwest of Jinzhong basin,Shanxi Province,China,for analysis of content andδ1 3 C of soil carbonates,content andδ1 3 C of CO 2 and δ1 3 C of parent rocks,hence to explore their variation with depth and controlling factors,and quantify ratio of pedogenic carbonates in soil carbon.Results show that in the upper layer(0 to 50 cm),the content of soil carbonates and CO 2 increase with depth,while the δ1 3 C of soil carbonates and CO 2 decrease with depth.In the lower layer (50-70 cm),the content of soil carbonates and CO 2 decrease with depth,and the δ1 3 C of soil carbonates and CO 2 increase with depth.The content and δ1 3 C of soil carbonates are mainly controlled by pedogenic carbonates proportion,while the content and δ1 3 C of CO 2 are mainly affected by at-mospheric CO 2 and soil CO 2 generated by organic matter decomposition in the upper layer,and impacted by karst process in soil-rock interface in the lower layer.The average proportion of pedogenic carbonates is 52%,42%,32% for abandoned farmland,forest land and brushland,respectively.This paper confirmed that the lithogenic carbonates can transform to pedogenic carbonates in north karst area with semiarid envi-ronment.
Keywords：karst carbon sinksoil carbonatepedogenic carbonatesδ1 3 C valuesoil CO 2
Publication Date：2016-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：9( 164-172 )