U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights


Forecasting the Decomposability of Organic Matter in Warming Tundra Soils
Published: October 25, 2018
Posted: April 22, 2019

Infrared spectroscopy predicted the initial decomposition of active layer and permafrost organic matter in Arctic soils.

The Science
Calibration models derived from the mid infrared (MIR) spectra of arctic tundra soils reasonably estimated the amount of carbon dioxide released from decomposing soil organic matter during short-term laboratory incubations. Clays, phenolics, aliphatics, silicates, carboxylic acids, and amides were identified as the most influential soil components predicting the initial decomposition of tundra soil organic matter.

The Impact
The potential decomposability of soil organic matter is usually determined from soil incubations, which require a substantial investment of time and effort. Application of MIR calibration models to already collected and archived soils could enable widespread assessments of the potential decomposability of Arctic soil organic matter, which are needed to constrain and benchmark model simulations of the responses of these soils to changing environmental conditions.

Summary
Vast amounts of soil organic matter are preserved in arctic soils due to the limiting effects of cold and wet environments on decomposer activity. With rapid high latitude warming due to climate change, the potential decomposability of this soil organic matter needs to be assessed. A team led by Argonne National Laboratory investigated the capability of MIR spectroscopy to quickly predict the amount of organic matter mineralized to carbon dioxide during short-term incubations of arctic soils. Active layer and upper permafrost soils from four tundra sites on the North Slope of Alaska were incubated for 60 days. A partial least square regression (PLSR) model, constructed from the MIR spectra of all incubated soils, reasonably predicted the amount of carbon mineralized during the incubations. Comparing PLSR models for soil subgroups defined by soil carbon or nitrogen contents and tundra type revealed that the best predictions were obtained for soils with <10% organic carbon and <0.6% total nitrogen. Analysis of loadings and beta coefficients from the PLSR models indicated a small number of influential spectral bands, including those indicating clays, phenolics, aliphatics, silicates, carboxylic acids, and amides present in the soils. Study results suggest that MIR spectroscopy could be a useful tool for estimating the initial decomposability of tundra soil organic matter, particularly for mineral soils and the mixed organic-mineral horizons of cryoturbated soils.

Contacts (BER PM)
Daniel Stover
SC-23.1
Terrestrial Ecosystem Science
Daniel.Stover@science.doe.gov

(PI Contact)
Julie D. Jastrow
Argonne National Laboratory
jdjastrow@anl.gov

(Corresponding Author Contact)
Roser Matamala
Argonne National Laboratory
matamala@anl.gov

Funding
This study was supported by the US Department of Energy, Office of Science, Office of Biological and Environmental Research, Climate and Environmental Science Division, Terrestrial Ecosystem Science Program under contract DE-AC02-06CH11357 to Argonne National Laboratory.

Publications
Matamala, R., J.D. Jastrow, F.J. Calderón, C. Liang, Z. Fan, G.J. Michaelson, and C.L. Ping. “Predicting the decomposability of arctic tundra soil organic matter with mid infrared spectroscopy.” Soil Biology and Biochemistry 129, 1-12 (2019). [DOI: 10.1016/j.soilbio.2018.10.014]

Related Links
Paper
SFA website

Topic Areas:

  • Research Area: Terrestrial Ecosystem Science

Division: SC-23.1 Climate and Environmental Sciences Division, BER

 

BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

Aug 24, 2019
New Approach for Studying How Microbes Influence Their Environment
A diverse group of scientists suggests a common framework and targeting of known microbial processes [more...]

Aug 08, 2019
Nutrient-Hungry Peatland Microbes Reduce Carbon Loss Under Warmer Conditions
Enzyme production in peatlands reduces carbon lost to respiration under future high temperatures. [more...]

Aug 05, 2019
Amazon Forest Response to CO2 Fertilization Dependent on Plant Phosphorus Acquisition
AmazonFACE Model Intercomparison. The Science Plant growth is dependent on the availabi [more...]

Jul 29, 2019
A Slippery Slope: Soil Carbon Destabilization
Carbon gain or loss depends on the balance between competing biological, chemical, and physical reac [more...]

Jul 15, 2019
Field Evaluation of Gas Analyzers for Measuring Ecosystem Fluxes
How gas analyzer type and correction method impact measured fluxes. The Science A side- [more...]

List all highlights (possible long download time)