skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Shifts in pore connectivity from precipitation versus groundwater rewetting increases soil carbon loss after drought

Journal Article · · Nature Communications

Droughts and other extreme precipitation events are predicted to increase in intensity, duration and extent, with uncertain implications for terrestrial carbon (C) sequestration. Soil wetting from above (precipitation) results in a characteristically different pattern of pore-filling than wetting from below (groundwater), with larger, well-connected pores filling before finer pore spaces, unlike groundwater rise in which capillary forces saturate the finest pores first. Here we demonstrate that pore-scale wetting patterns interact with antecedent soil moisture conditions to alter pore-, core- and field-scale C dynamics. Drought legacy and wetting direction are perhaps more important determinants of short-term C mineralization than current soil moisture content in these soils. Our results highlight that microbial access to C is not solely limited by physical protection, but also by drought or wetting-induced shifts in hydrologic connectivity. We argue that models should treat soil moisture within a three-dimensional framework emphasizing hydrologic conduits for C and resource diffusion.

Research Organization:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
Sponsoring Organization:
USDOE
DOE Contract Number:
AC05-76RL01830
OSTI ID:
1414537
Report Number(s):
PNNL-SA-121121; 48713; 49369; KP1702010
Journal Information:
Nature Communications, Vol. 8, Issue 1; ISSN 2041-1723
Publisher:
Nature Publishing Group
Country of Publication:
United States
Language:
English

References (55)

Emission of CO2 from tropical riparian forest soil is controlled by soil temperature, soil water content and depth to water table journal January 2016
Properties of Soil Pore Space Regulate Pathways of Plant Residue Decomposition and Community Structure of Associated Bacteria journal April 2015
Responses of soil respiration to simulated precipitation pulses in semiarid steppe under different grazing regimes journal September 2008
Soil carbon flux following pulse precipitation events in the shortgrass steppe journal October 2009
A theoretical analysis of microbial eco-physiological and diffusion limitations to carbon cycling in drying soils journal June 2014
Response of microbial biomass to alternate moist and dry conditions in a soil incubated with 14C- and 15N-labelled plant material journal January 1985
Global warming and changes in drought journal December 2013
Automated System for Collecting Multiple, Sequential Samples from Soil Water Percolation Samplers under Continuous Vacuum journal June 2006
Automated Analysis of Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectra of Natural Organic Matter journal July 2006
Response of osmolytes in soil to drying and rewetting journal March 2014
Simulations of ecosystem hydrological processes using a unified multi-scale model journal January 2015
Global spatiotemporal distribution of soil respiration modeled using a global database journal January 2015
Comparison of dialysis and solid-phase extraction for isolation and concentration of dissolved organic matter prior to Fourier transform ion cyclotron resonance mass spectrometry journal June 2012
Soil carbon and nitrogen mineralization: Theory and models across scales journal July 2009
Characterization of dissolved organic matter in Lake Superior and its watershed using ultrahigh resolution mass spectrometry journal February 2012
Water table fluctuations and soil biogeochemistry: An experimental approach using an automated soil column system journal February 2014
Hot spots, hot moments, and spatio-temporal controls on soil CO2 efflux in a water-limited ecosystem journal October 2014
Reappraisal of drying and wetting effects on C and N mineralization and fluxes in soils journal April 2009
Coating of AFM probes with aquatic humic and non-humic NOM to study their adhesion properties journal June 2013
Regulation of carbon mineralization rates by soil structure and water in an agricultural field and a prairie-like soil journal November 2006
Differences in soluble organic carbon chemistry in pore waters sampled from different pore size domains journal April 2017
Prolonged drought changes the bacterial growth response to rewetting journal September 2015
Strong pulse effects of precipitation events on soil microbial respiration in temperate forests journal August 2016
The Dual Arrhenius and Michaelis-Menten kinetics model for decomposition of soil organic matter at hourly to seasonal time scales journal October 2011
Relationships between intra-aggregate pore structures and distributions of Escherichia coli within soil macro-aggregates journal January 2013
Resilience vs. historical contingency in microbial responses to environmental change journal May 2015
Protection of soil carbon within macro-aggregates depends on intra-aggregate pore characteristics journal November 2015
Soil biophysical controls over rice straw decomposition and sequestration in soil: The effects of drying intensity and frequency of drying and wetting cycles journal March 2011
Direct soil moisture controls of future global soil carbon changes: An important source of uncertainty: SOIL MOISTURE AND SOIL CARBON journal July 2011
Advanced Solvent Based Methods for Molecular Characterization of Soil Organic Matter by High-Resolution Mass Spectrometry journal April 2015
Regulation of soil organic C mineralisation at the pore scale journal February 2013
Effects of soil rewetting and thawing on soil gas fluxes: a review of current literature and suggestions for future research journal January 2012
How air-drying and rewetting modify soil organic matter characteristics: An assessment to improve data interpretation and inference journal January 2015
Microbial activity in response to water-filled pore space of variably eroded southern Piedmont soils journal January 1999
On the origin of carbon dioxide released from rewetted soils journal October 2016
Unraveling the mechanisms underlying pulse dynamics of soil respiration in tropical dry forests journal October 2016
The application of electrospray ionization coupled to ultrahigh resolution mass spectrometry for the molecular characterization of natural organic matter journal January 2007
Soil pores and their contributions to soil carbon processes journal February 2017
Can current moisture responses predict soil CO 2 efflux under altered precipitation regimes? A synthesis of manipulation experiments journal January 2014
Structure formation and its consequences for gas and water transport in unsaturated arable and forest soils journal May 2005
A simple and efficient method for the solid-phase extraction of dissolved organic matter (SPE-DOM) from seawater: SPE-DOM from seawater journal June 2008
Microbial biogeography at the soil pore scale journal February 2011
The effect of soil drying on humus decomposition and nitrogen availability journal September 1958
Relationships of soil respiration to microbial biomass, substrate availability and clay content journal February 2003
Spatial location of carbon decomposition in the soil pore system journal December 2004
Effects of soil compaction and water‐filled pore space on soil microbial activity and N losses journal July 1992
Climate extremes and the carbon cycle journal August 2013
Pore-Scale Redistribution of Water during Wetting of Air-Dried Soils As Studied by Low-Field NMR Relaxometry journal June 2003
A Unified Multiscale Model for Pore-ScaleFlow Simulations in Soils journal January 2014
Historical precipitation predictably alters the shape and magnitude of microbial functional response to soil moisture journal February 2016
Precipitation pulses and soil CO 2 flux in a Sonoran Desert ecosystem journal February 2007
The effects of water table manipulation and elevated temperature on the net CO 2 flux of wet sedge tundra ecosystems journal January 1998
Changes in soil moisture predict soil carbon losses upon rewetting in a perennial semiarid steppe in SE Spain journal February 2017
Production, oxidation, emission and consumption of methane by soils: A review journal January 2001
Causes of variation in soil carbon predictions from CMIP5 Earth system models and comparison with observations journal January 2012