鼎湖山森林土壤^(14)C表观年龄及δ^(13)C分布特征  

(14)~C APPARENT AGES AND δ(13)~C DISTRIBUTION OF FOREST SOILS IN DINGHUSHAN NATURAL RESERVE

作　　者：沈承德[1] 易惟熙[1] 孙彦敏[1] 邢长平[1] 杨英[1] 彭少麟[2] 李志安[2] 

机构地区：[1]中国科学院广州地球化学研究所 [2]中国科学院华南植物研究所,广州510650

出　　处：《第四纪研究》2000年第4期335-344,共10页Quaternary Sciences

基　　金：国家自然科学基金!(批准号:49973009;39899370和49894170); 中国科学院"九五"重大项目!(批准号:

摘　　要：本文结出鼎湖山五棵松、庆云寺和坑口 ３个森林土壤剖面有机碳１４Ｃ表观年龄，该地区成壤过程持续时间约为 ５００～ １０００ａ；最大１４Ｃ表观年龄分别为 ５ ５７２± ９４ａＢ．Ｐ．， ８ ６６３±１１２ａＢ．Ｐ和２８８３±７７ａＢ．Ｐ．３个剖面有机碳及其δ１３Ｃ变化均可分成２段：表面至约４０ｃｍ段，δ１３Ｃ变化范围分别为－２７４‰～－２４．１‰，－２７．５‰～－２２．２‰和－２４．４‰～－２０．１‰，有机碳含量变率大，有机质由“活动型”有机碳构成 ５约４０ｃｍ至约１６０ｃｍ段，δ１３Ｃ和有机碳趋于稳定，有机质由“稳定型”有机碳构成。剖面有机碳δ１３Ｃ平均值不但可用于Ｃ３，Ｃ４植被之区分，还可用于阔叶林、针叶林等植被类型之区分。The bulk organic carbon, 14C apparent ages and δ13C distribution of the tropical and subtropical forest soil profiles in Dinghushan natural reserve (DNR) (23°09′22″ - 23°11′ 30″ N, 112° 30′ 39″ - 1 12° 33′ 41″E), located in the northeast of Zhaoqing, Guangdong Province, have been studied preliminarily in this paper. Wukesong, Qingyunsi and Kengkon soil profiles have been chosen for the investigation which ate at different elevations along the southeast-northwest direction in the middle part of DNR. The vegetation in the Wukesong, Qingyunsi and Kengkon soil profiles are respectively the coniferous and broad-leaf mixed forests, monsoon evergreen broad-leaf forests, and coniferous forests. The measurements of 14C and 13 C were carried out respectively using 1 220 Quantulus ultralow-background liquid scintillation spectrometer and Finigen Model-251 mass spectrometer. Soil organic carbon was determined by the sulfdric acid-potassium dichromate method. Soil organic carbons are always involved in soil genesis processes and the soil organic carbons produced in the earlier stage are continuously mixed with those produced in the later stage, the measured 14C ages based on the total soil organic carbons obviously tend to be younger. Hence, the 14C ages of the total soil organic carbons are usually referred as the 14C apparent ages of the soil organic carbons, which can be as the mean residence time under the steady condition. Based on the 14C apparent ages of the forest soils of Wukesong, Qingyunsi and Kengkou profiles in DNR, it was found that the duration of the forest soil genesis process ranged approximately from 500 to 1 000 years. The mean residence times of the total organic carbon in the forest soils may represent the burial ages of the soils. The bases of the Wukesong, Qingyunsi and Kengkou soil profiles, whose maximum 14C apparent ages of the soil organic carbons, are respectively 5 572 ± 94aB. P., 8 663 ± 1 12aB. P. and 2 883 ± 77aB.P., reach parent rocks. The δ13C variations with depth i

关 键 词：鼎湖山 森林土壤 碳14表观年龄 碳同位素 

分 类 号：S714.2[农业科学—林学]