DOI: 10.1002/2014GL061399
论文题名: Assessing five evolving microbial enzyme models against field measurements from a semiarid savannah - What are the mechanisms of soil respiration pulses?
作者: Zhang X. ; Niu G.-Y. ; Elshall A.S. ; Ye M. ; Barron-Gafford G.A. ; Pavao-Zuckerman M.
刊名: Geophysical Research Letters
ISSN: 0094-9787
EISSN: 1944-9518
出版年: 2014
卷: 41, 期: 18 起始页码: 6428
结束页码: 6434
语种: 英语
英文关键词: Birch effect
; climate change
; extracellular enzyme
; land surface model
; microbial respiration
; soil organic carbon
Scopus关键词: Bacteria
; Carbon
; Climate change
; Drought
; Enzymes
; Lakes
; Microorganisms
; Moisture
; Moisture control
; Organic carbon
; Pulse generators
; Soil moisture
; Soils
; Storms
; Birch effect
; Extracellular enzymes
; Land surface modeling
; Microbial respiration
; Soil organic carbon
; Climate models
; assessment method
; deciduous tree
; enzyme activity
; experimental study
; land surface
; measurement method
; microbial activity
; precipitation (climatology)
; rainfall
; semiarid region
; soil degradation
; soil microorganism
; soil moisture
; soil organic matter
; soil respiration
英文摘要: Soil microbial respiration pulses in response to episodic rainfall pulses (the "Birch effect") are poorly understood. We developed and assessed five evolving microbial enzyme models against field measurements from a semiarid savannah characterized by pulsed precipitation to understand the mechanisms to generate the Birch pulses. The five models evolve from an existing four-carbon (C) pool model to models with additional C pools and explicit representations of soil moisture controls on C degradation and microbial uptake rates. Assessing the models using techniques of model selection and model averaging suggests that models with additional C pools for accumulation of degraded C in the dry zone of the soil pore space result in a higher probability of reproducing the observed Birch pulses. Degraded C accumulated in dry soil pores during dry periods becomes immediately accessible to microbes in response to rainstorms, providing a major mechanism to generate respiration pulses. Explicitly representing the transition of degraded C and enzymes between dry and wet soil pores in response to soil moisture changes and soil moisture controls on C degradation and microbial uptake rates improve the models' efficiency and robustness in simulating the Birch effect. Assuming that enzymes in the dry soil pores facilitate degradation of complex C during dry periods (though at a lower rate) results in a greater accumulation of degraded C and thus further improves the models' performance. However, the actual mechanism inducing the greater accumulation of labile C needs further experimental studies. Key Points We developed and assessed five microbial enzyme models against field dataDOC accumulates in dry soil pore and is available to microbe in response to rainThe transitions of DOC and enzymes between dry and wet soil pores are important ©2014. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84911191318&doi=10.1002%2f2014GL061399&partnerID=40&md5=beca8ca400fc464fa549e9f611a23988
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/7051
Appears in Collections: 气候减缓与适应
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作者单位: Key Laboratory of Regional Climate-Environment Research for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
Recommended Citation:
Zhang X.,Niu G.-Y.,Elshall A.S.,et al. Assessing five evolving microbial enzyme models against field measurements from a semiarid savannah - What are the mechanisms of soil respiration pulses?[J]. Geophysical Research Letters,2014-01-01,41(18).