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

BER 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.

Summary
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
wjriley@lbl.gov

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

Publications
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 10, 2019
Quantifying Decision Uncertainty in Water Management via a Coupled Agent-Based Model
Considering risk perception can improve the representation of human decision-making processes in age [more...]

May 09, 2019
Projecting Global Urban Area Growth Through 2100 Based on Historical Time Series Data and Future Scenarios
Study provides country-specific urban area growth models and the first dataset on country-level urba [more...]

May 05, 2019
Calibrating Building Energy Demand Models to Refine Long-Term Energy Planning
A new, flexible calibration approach improved model accuracy in capturing year-to-year changes in bu [more...]

May 03, 2019
Calibration and Uncertainty Analysis of Demeter for Better Downscaling of Global Land Use and Land Cover Projections
Researchers improved the Demeter model’s performance by calibrating key parameters and establi [more...]

Apr 22, 2019
Representation of U.S. Warm Temperature Extremes in Global Climate Model Ensembles
Representation of warm temperature events varies considerably among global climate models, which has [more...]

List all highlights (possible long download time)