气候变化领域集成服务门户(CCPortal): Linear two-pool models are insufficient to infer soil organic matter decomposition temperature sensitivity from incubations

CCPortal

DOI	10.1007/s10533-020-00678-3
	Linear two-pool models are insufficient to infer soil organic matter decomposition temperature sensitivity from incubations
	Tang J.; Riley W.J.
发表日期	2020
ISSN	0168-2563
起始页码	251
结束页码	261
卷号	149 期号:3
英文摘要	Terrestrial carbon (C)-climate feedbacks depend strongly on how soil organic matter (SOM) decomposition responds to temperature. This dependency is often represented in land models by the parameter Q10, which quantifies the relative increase of microbial soil respiration per 10 °C temperature increase. Many studies have conducted paired laboratory soil incubations and inferred “active” and “slow” pool Q10 values by fitting linear two-pool models to measured respiration time series. Using a recently published incubation study (Qin et al. in Sci Adv 5(7):eaau1218, 2019) as an example, here we first show that the very high parametric equifinality of the linear two-pool models may render such incubation-based Q10 estimates unreliable. In particular, we show that, accompanied by the uncertain initial active pool size, the slow pool Q10 can span a very wide range, including values as high as 100, although all parameter combinations are producing almost equally good model fit with respect to the observations. This result is robust whether or not interactions between the active and slow pools are considered (typically these interactions are not considered when interpreting incubation data, but are part of the predictive soil carbon models). This very large parametric equifinality in the context of interpreting incubation data is consistent with the poor temporal extrapolation capability of linear multi-pool models identified in recent studies. Next, using a microbe-explicit SOM model (RESOM), we show that the inferred two pools and their associated parameters (e.g., Q10) could be artificial constructs and are therefore unreliable concepts for integration into predictive models. We finally discuss uncertainties in applying linear two-pool (or more generally multiple-pool) models to estimate SOM decomposition parameters such as temperature sensitivities from laboratory incubations. We also propose new observations and model structures that could enable better process understanding and more robust predictive capabilities of soil carbon dynamics. © 2020, The Author(s).
英文关键词	Equifinality; Laboratory incubation; Soil respiration; Temperature sensitivity; Two-pool models
语种	英语
scopus关键词	climate feedback; decomposition; soil carbon; soil organic matter; soil respiration; soil temperature; temperature effect; temporal analysis
来源期刊	Biogeochemistry
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/153126
作者单位	Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
推荐引用方式 GB/T 7714	Tang J.,Riley W.J.. Linear two-pool models are insufficient to infer soil organic matter decomposition temperature sensitivity from incubations[J],2020,149(3).
APA	Tang J.,&Riley W.J..(2020).Linear two-pool models are insufficient to infer soil organic matter decomposition temperature sensitivity from incubations.Biogeochemistry,149(3).
MLA	Tang J.,et al."Linear two-pool models are insufficient to infer soil organic matter decomposition temperature sensitivity from incubations".Biogeochemistry 149.3(2020).