Microscale water distribution and its effects on organic carbon decomposition in unsaturated soils

Yan, Zhifeng1; Wang, Tiejun1; Wang, Lichun2; Yang, Xiaofan3; Smith, Peyton8; Hilpert, Markus5; Li, Siliang1; Shang, Jianying6; Bailey, Vanessa4; Liu, Chongxuan7

2018-12-10

10.1016/j.scitotenv.2018.06.365

SCIENCE OF THE TOTAL ENVIRONMENT   影响因子和分区

0048-9697

1879-1026

Microscale water distribution in the subsurface is key to many geochemical and biogeochemical reactions. This study investigated microscale water distribution and movement in unsaturated soils using micro-continuum hydrodynamic models, and examined the effect of microscale water distribution on organic carbon (C) decomposition using a micro-continuum biogeochemical reaction model. The micro-continuum hydrodynamic model that relates capillary pressure to porosity captured the measured water imbibition curve at the core scale, and exhibited reasonable water distribution and movement at the microscale. The simulations of organic C decomposition illustrate that microscale water distribution strongly affected the distribution of C decomposition rates by regulating the availability of dissolved organic C and oxygen. Particularly, changes in water distribution altered the location and intensity of reactive hotspots and thereby CO2 flux from soils. The microscale interactions between water content and organic C decomposition rate provide underlying mechanisms for explaining macroscale phenomenon observed in laboratory and fields. Overall, this study presents a useful tool for explicating hydro-biogeochemical behaviors in the subsurface by integrating micro-continuum hydrodynamic and biogeochemical reaction modeling. (c) 2018 Published by Elsevier B.V.

Microscale water distribution Soil water content Carbon decomposition CO2 flux Micro-continuum models X-ray microtomography

SCI ; CPCI-S ; EI

英语

通讯

Southern University of Science and Technology[G01296001]

Environmental Sciences & Ecology

Environmental Sciences

WOS:000445164000107

ELSEVIER SCIENCE BV

20182805534667

Biogeochemistry ; Carbon dioxide ; Continuum mechanics ; Dissolved oxygen ; Hydrodynamics ; Organic carbon ; Soil moisture ; Water supply systems

Water Supply Systems:446.1 ; Geochemistry:481.2 ; Soils and Soil Mechanics:483.1 ; Biochemistry:801.2 ; Organic Compounds:804.1 ; Inorganic Compounds:804.2 ; Mechanics:931.1

ENVIRONMENT/ECOLOGY

Web of Science

1.Tianjin Univ, Inst Surface Earth Syst Sci, Tianjin 300072, Peoples R China
2.Univ Texas Austin, Dept Geol Sci, Austin, TX 78712 USA
3.Beijing Normal Univ, Sch Nat Resources, Fac Geog Sci, Beijing 100875, Peoples R China
4.Pacific Northwest Natl Lab, Richland, WA 99354 USA
5.Columbia Univ, Dept Environm Hlth Sci, New York, NY 10032 USA
6.China Agr Univ, Coll Resources & Environm Sci, Beijing 100193, Peoples R China
7.Southern Univ Sci & Technol, Sch Environm Sci & Engn, Shenzhen 518055, Peoples R China
8.Texas A&M Univ, Dept Soil & Crop Sci, College Stn, TX 77843 USA

Yan, Zhifeng,Wang, Tiejun,Wang, Lichun,et al. Microscale water distribution and its effects on organic carbon decomposition in unsaturated soils[J]. SCIENCE OF THE TOTAL ENVIRONMENT,2018,644:1036-1043.

Yan, Zhifeng.,Wang, Tiejun.,Wang, Lichun.,Yang, Xiaofan.,Smith, Peyton.,...&Liu, Chongxuan.(2018).Microscale water distribution and its effects on organic carbon decomposition in unsaturated soils.SCIENCE OF THE TOTAL ENVIRONMENT,644,1036-1043.

Yan, Zhifeng,et al."Microscale water distribution and its effects on organic carbon decomposition in unsaturated soils".SCIENCE OF THE TOTAL ENVIRONMENT 644(2018):1036-1043.