土壤有机碳储量估算与土地利用的关系研究

土地利用方式的变化在土壤有机碳(Soil Organic Carbon,SOC)积累的过程中起着非常重要的作用。目前在估算土壤有机碳储量的过程中,一直没有重视土地利用属性。运用基于土壤学专业知识的连接方法 (pedological professional knowledge-based method,PKB法),结合江苏省新沂县1∶20万土壤图,1∶20万土地利用图和1∶20万土壤类型土地利用混合图,估算了各图在不同土壤剖面点数情况下的新沂县SOC储量,并将三者在最佳剖面点数下估算出的SOC储量和SOC密度(SOCD)进行了比较及精度评价。结果表明:在土壤类型图、土地利用图和土壤类型土地利用混合图上进行的PKB法连接时最佳剖面点数均为397点,最佳网格为2 km×2 km;在中比例尺图件上进行PKB法连接估算SOC储量时,综合考虑土壤类型和土地利用类型可以大大提高估算精度,同时土地利用类型属性比土壤类型属性更为重要。研究结果可为在中比例尺条件下提高SOC估算精度提供科学依据。

Relationship of Soil Organic Carbon Storage Estimation with Land Use Types

The change of land use types plays important role in the soil organic carbon(SOC) accumulation processes.But land use attribute has not been paid attention to the SOC storage.This research will combine pedological professional knowledge-based method(PKB) with 1∶2 00000 soil map,1∶2 00000 land use map and 1∶2 00000 soil types/land use mixing map in Xinyi County,Jiangsu Province to estimate the SOC in different soil profile numbers.The research has also compared the SOC storage total quantity with SOC density in the three maps' best profile number and evaluated their precision.The results showed that the best profile number in soil map,land use map and soil types/ land use mixing map was 397.The best grid was 2 km×2 km.When using PKB to estimate the SOC storage in the middle scale map,integration soil types and land use types would increase the precision and land use types was more important than the soil types.The results will provide the scientific data to increase the SOC estimating precision in the middle scale map.