DOI: 10.1016/j.quascirev.2015.05.021
Scopus记录号: 2-s2.0-84945447507
论文题名: Radiocarbon evidence for decomposition of aged organic matter in the vadose zone as the main source of speleothem carbon
作者: Noronha A.L. ; Johnson K.R. ; Southon J.R. ; Hu C. ; Ruan J. ; McCabe-Glynn S.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2015
卷: 127 起始页码: 37
结束页码: 47
语种: 英语
英文关键词: Carbon cycle
; Carbon isotopes
; Radiocarbon
; Soil carbon
; Speleothems
Scopus关键词: Caves
; Forestry
; Groundwater
; Isotopes
; Landforms
; Carbon cycles
; Carbon isotopes
; Radiocarbon
; Soil carbon
; Speleothems
; Soils
; carbon cycle
; carbon isotope
; decomposition
; radiocarbon dating
; soil carbon
; soil organic matter
; speleothem
; vadose zone
; China
; Heshang Cave
; Hubei
英文摘要: Several recent studies have used records of the radiocarbon (14C) bomb peak in speleothems to inversely model the soil a14CO2 and the age distribution of soil organic material (SOM) above caves, in part to investigate the potential of speleothems as sensitive records of past SOM dynamics. The results of these modeling studies have suggested that soil CO2 at karst sites is derived primarily from the decomposition of SOM with turnover times on the order of decades to centuries. This result is in stark contrast with observations of soil a14CO2 at non-karst sites, which indicate that soil CO2 is derived primarily from root respiration and decomposition of SOM with much shorter turnover times. This discrepancy suggests that SOM in karst settings may have a very different age distribution than sites that have been studied previously and/or that soil CO2 is not the main source of speleothem carbon. To help resolve this discrepancy, we present an improved inverse model which we use to estimate the age of CO2 above several caves. We also present results from a detailed case study of soil carbon dynamics at Heshang Cave, China. This work demonstrates that SOM in karst sites may be much older than SOM in non-karst soils that have been studied previously, but that CO2 produced in the shallow soil zone is unlikely to be the main source of speleothem carbon. A review of the literature suggests that the most likely explanation for the aforementioned discrepancy is that decomposition of down-washed SOM in the vadose zone is the dominant source of speleothem carbon. © 2015 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59801
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Earth System Science, University of California, Irvine, United States; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China; Jackson School of Geosciences, University of Texas, Austin, United States; Laboratoire des Sciences du Climat et de l'Environnement (LSCE), CNRS/CEA/UVSQ, L'Orme des Merisiers, Gif-sur-Yvette Cedex, France
Recommended Citation:
Noronha A.L.,Johnson K.R.,Southon J.R.,et al. Radiocarbon evidence for decomposition of aged organic matter in the vadose zone as the main source of speleothem carbon[J]. Quaternary Science Reviews,2015-01-01,127