DOI: 10.1111/gcb.13938
Scopus记录号: 2-s2.0-85033490921
论文题名: Dynamics of soil biogeochemical gas emissions shaped by remolded aggregate sizes and carbon configurations under hydration cycles
作者: Ebrahimi A. ; Or D.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2018
卷: 24, 期: 1 起始页码: e378
结束页码: e392
语种: 英语
英文关键词: biogeochemical gas fluxes
; mechanistic modeling
; microbial community
; N2O emissions
; soil aggregate
; soil structure
Scopus关键词: aggregate size
; biogeochemical cycle
; greenhouse gas
; hydration
; microbial community
; soil aggregate
; soil biota
; soil emission
; soil structure
英文摘要: Changes in soil hydration status affect microbial community dynamics and shape key biogeochemical processes. Evidence suggests that local anoxic conditions may persist and support anaerobic microbial activity in soil aggregates (or in similar hot spots) long after the bulk soil becomes aerated. To facilitate systematic studies of interactions among environmental factors with biogeochemical emissions of CO2, N2O and CH4 from soil aggregates, we remolded silt soil aggregates to different sizes and incorporated carbon at different configurations (core, mixed, no addition). Assemblies of remolded soil aggregates of three sizes (18, 12, and 6 mm) and equal volumetric proportions were embedded in sand columns at four distinct layers. The water table level in each column varied periodically while obtaining measurements of soil GHG emissions for the different aggregate carbon configurations. Experimental results illustrate that methane production required prolonged inundation and highly anoxic conditions for inducing measurable fluxes. The onset of unsaturated conditions (lowering water table) resulted in a decrease in CH4 emissions while temporarily increasing N2O fluxes. Interestingly, N2O fluxes were about 80% higher form aggregates with carbon placement in center (anoxic) core compared to mixed carbon within aggregates. The fluxes of CO2 were comparable for both scenarios of carbon sources. These experimental results highlight the importance of hydration dynamics in activating different GHG production and affecting various transport mechanisms about 80% of total methane emissions during lowering water table level are attributed to physical storage (rather than production), whereas CO2 emissions (~80%) are attributed to biological activity. A biophysical model for microbial activity within soil aggregates and profiles provides a means for results interpretation and prediction of trends within natural soils under a wide range of conditions. © 2017 John Wiley & Sons Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/110578
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland
Recommended Citation:
Ebrahimi A.,Or D.. Dynamics of soil biogeochemical gas emissions shaped by remolded aggregate sizes and carbon configurations under hydration cycles[J]. Global Change Biology,2018-01-01,24(1)