DOI: 10.1029/2018GB005950
论文题名: Soil Organic Matter Persistence as a Stochastic Process: Age and Transit Time Distributions of Carbon in Soils
作者: Sierra C.A. ; Hoyt A.M. ; He Y. ; Trumbore S.E.
刊名: Global Biogeochemical Cycles
ISSN: 0886-6236
EISSN: 1944-9224
出版年: 2018
卷: 32, 期: 10 语种: 英语
英文关键词: age structure
; biogeochemical cycle
; carbon sequestration
; model
; organic carbon
; persistence
; soil carbon
; soil organic matter
; stochasticity
; time series analysis
学科: biogeochemical cycling
; carbon storage
; model diagnostics
; soil carbon
; soil models
; time scales
中文摘要: The question of why some types of organic matter are more persistent while others decompose quickly in soils has motivated a large amount of research in recent years. Persistence is commonly characterized as turnover or mean residence time of soil organic matter (SOM). However, turnover and residence times are ambiguous measures of persistence, because they could represent the concept of either age or transit time. To disambiguate these concepts and propose a metric to assess SOM persistence, we calculated age and transit time distributions for a wide range of soil organic carbon models. Furthermore, we show how age and transit time distributions can be obtained from a stochastic approach that takes a deterministic model of mass transfers among different pools and creates an equivalent stochastic model at the level of atoms. Using this approach we show the following: (1) Age distributions have relatively old mean values and long tails in relation to transit time distributions, suggesting that carbon stored in soils is on average much older than carbon in the release flux. (2) The difference between mean ages and mean transit times is large, with estimates of soil organic carbon persistence on the order of centuries or millennia when assessed using ages and on the order of decades when using transit or turnover times. (3) The age distribution is an appropriate metric to characterize persistence of SOM. An important implication of our analysis is that random chance is a factor that helps to explain why some organic matter persists for millennia in soil. ©2018. The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/160186
Appears in Collections: 气候变化与战略
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作者单位: Max Planck Institute for Biogeochemistry, Jena, Germany; Department of Earth System Science, University of California, Irvine, CA, United States
Recommended Citation:
Sierra C.A.,Hoyt A.M.,He Y.,et al. Soil Organic Matter Persistence as a Stochastic Process: Age and Transit Time Distributions of Carbon in Soils[J]. Global Biogeochemical Cycles,2018-01-01,32(10)