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

Searchable Research Highlights

A New Approach to Represent Multi-Consumer, Multi-Species Soil Biogeochemical Reactions for Earth System Models
Published: September 05, 2017
Posted: November 02, 2017

A new kinetics formulation (SUPECA) scales mixed reaction networks.

The Science
Environmental biogeochemistry emerges from microbially-mediated redox reactions in a complex web of consumers and substrates. The two dominant approaches to represent these reactions, Monod and Synthesizing Unit (SU), are unable to scale consistently across complex reaction networks and fail to include substrate limitations, respectively. The authors here extend these approaches (termed SUPECA) to general redox reaction networks to improve terrestrial ecosystem biogeochemical modeling. The authors also applied the SUPECA approach to analyze the soil moisture constraint on soil organic matter decomposition and compared to a benchmark dataset to show our approach accurately represents this constraint across a wide range of soil moisture conditions. The SUPECA approach is being applied in NGEE-Arctic modeling analyses and in DOE’s Earth System Model (E3SM) Land Model (ELM).

The Impact
The authors demonstrate that (1) existing Monod and Synthesizing Unit kinetics are scaling inconsistent; (2) the new SUPECA kinetics rectifies these problems; and (3) that SUPECA is well-suited to trait-based modeling approaches. The authors also show that SUPECA kinetics enables mechanistic modeling of soil moisture effects on organic matter decomposition.

Soil organic matter decomposition occurs in an extremely complex network of reactions, substrates, and consumers. To address this problem in a manner amenable to land model representation (e.g., E3SM’s ELM), the authors extended the Equilibrium Chemistry Approximation approach to generic biogeochemical networks that include redox reactions (termed the SUPECA (Synthesizing Unit plus ECA) kinetics). The authors demonstrated that SUPECA consistently scales from single Monod type and redox reactions to a reaction network, while the popular dual Monod kinetics and Synthesizing Unit kinetics fail to do so. It is also demonstrated that SUPECA kinetics is superior to dual Monod kinetics in modeling substrate competition in the presence of substrate-mineral interactions. By applying SUPECA to soil organic matter decomposition, the authors showed that soil aggregates have significant impacts and illustrate potential flaws in current ESM land model approaches. The authors are applying the SUPECA approach in NGEE-Arctic modeling analyses and in DOE’s ELM.

Contacts (BER PM)
Daniel Stover and Dorothy Koch
daniel.stover@science.doe.gov (301-903-0289) and Dorothy.Koch@science.doc.gov (301-903-0105)

(PI Contact)
William J. Riley
Lawrence Berkeley National Lab

DE-AC02-05CH11231 as part of NGEE-Arctic project and Accelerated Climate Modeling for Energy (ACME) project.

Tang, J.-Y. and W.J. Riley. 2017. “SUPECA Kinetics for Scaling Redox Reactions in Networks of Mixed Substrates and Consumers and an Example Application to Aerobic Soil Respiration.” Geosci. Model Dev. 10, 3277-95. 10.5194/gmd-10-3277-2017.

Topic Areas:

  • Research Area: Earth and Environmental Systems Modeling
  • Research Area: Subsurface Biogeochemical Research
  • Research Area: Carbon Cycle, Nutrient Cycling
  • Research Area: Next-Generation Ecosystem Experiments (NGEE)

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

May 28, 2018
New Method Helps Predict Metabolite Concentrations, Rate Constants, and Enzyme Regulation Within Cells
Researchers use Neurospora crassa, a reliable model organism, to demonstrate new method [more...]

Mar 19, 2018
Portfolio of Land Use Strategies Can Increase Future Carbon Sequestration in Moist Temperate Forests
The Science A team of scientists at Oregon State University and Univer [more...]

Mar 02, 2018
Influence of Hydroclimate Variability on Power System Operations Revealed through Integrated Modeling
Integrated multi-sector modeling shows that variations in water availability associated with El [more...]

Mar 01, 2018
Newly Discovered Bacteria Can Break Down Biomass
The bacteria from ruminants' digestive systems could provide insights for biomass conversion.more...]

Feb 28, 2018

New Technology for Consistently Identifying Proteins from a Dozen Cells

A new platform melding microfluidics and robotics allows more in-depth bioanalysis with fewer c [more...]