Focus Areas

Climate Change Mitigation

Terrestrial Carbon Sequestration (and Terrestrial Carbon Processes)

Scientific Imperative.
Limitations in current soil carbon models cripple scientists’ ability to predict climate effects on CO2 fluxes or to evaluate carbon sequestration and land management strategies. Four major gaps in the understanding of soil carbon dynamics have been identified (e.g., by BERAC, DOE, and USDA) that are important for both coupled climate-carbon modeling and carbon management, and that can be addressed in the next 5 years. Specifically, the priority areas for soil carbon research are (1) the effect of plant allocation and species on carbon residence time; (2) physical protection of soil organic matter, by minerals and aggregation; (3) temperature and moisture interactions; and (4) testing and improvement of model performance. We have in hand sufficient understanding and data to begin developing much improved model parameterizations for several of these areas.

Core capabilities.
In particular, radiocarbon (14C) measurements can be used to test models of soil carbon turnover and create global databases for model testing. The BER memo contains funding for a new project proposed to DOE in March 2006 to take full advantage of radiocarbon data, much of which is DOE data (“A Radiocarbon Database for Determining Soil Carbon Turnover Times and Modeling Terrestrial Carbon Cycling,” PI Torn, TCP).Moreover, we will ensure that these data are used to improve modeling through our work on the Integrated Terrestrial Carbon Model project (lead institution: ORNL, PI Mac Post; Berkeley Lab PI: Torn), wherein we are responsible for developing a working group on soil carbon models.

At the same time, it is essential to conduct experiments in parallel with model development. Berkeley Lab currently has active research on how plant allocation and mineral interactions affect on soil carbon turnover. This work has been funded largely by the Terrestrial Carbon Sequestration program (TCS), and has been very productive (Project title: Quantifying the Importance of Belowground Plant Allocation for Sequestration of Carbon in Soils, PI Torn, TCS), and is projected in the BER memo to continue at its current level. We propose to enhance carbon stabilization research by entraining into soil carbon research Berkeley Lab’s state of the art facilities in imaging (e.g., Advanced Light Source, National Center for Electron Microscopy), genomics (e.g., JGI), and advanced (e.g., Energy Biosciences Institute).

Finally, there is currently little experimental or theoretical research on the effect of temperature and moisture on decomposition, and thus DOE is not on track to bridge this major gap in terrestrial carbon prediction. We propose to use 14C, 13C, advanced imaging, and soils from decommissioned FACE sites to tackle this critical problem (Berkeley Lab participated in the recent FACE workshop at ORNL and is contributing to the workshop report). Much of this science agenda was presented to the BERAC review of the Terrestrial Carbon Processes Program in 2005, and BERAC recommended it for support, specifically calling out the need for observational constraints and a (radiocarbon) database on turnover times.

At Berkeley Lab, we have the expertise and facilities to make rapid progress. Several other national laboratories, such as Argonne, Oak Ridge, Livermore, and Los Alamos Laboratories also have specialized expertise and facilities to contribute to this task.

Special strengths of Berkeley Lab for soil carbon experiments and modeling include:

• Strong science vision, focused on products for NACP, GCMs, and C sequestration
• Tight integration of experiments, data, and models
• Expertise in quantifying soil carbon turnover using radiocarbon and other isotopes
• Specialized facilities such as the Advanced Light Source and Joint Genome Institute.
• Close collaboration with other national laboratories and universities
• Crosscutting research across levels of biological complexity, from microbial genomics to whole ecosystem.
• Synergistic activities, such as the Energy Biosciences Institute

Berkeley Lab has recognized expertise and active research in soil carbon sequestration. Last year, five Ph.D. scientists were supported to work on soil carbon studies.

Scientific Milestones.
The next five years of Berkeley Lab research in this area will be integrated with three CCRD priorities: soil carbon models, ecosystem response, and biofuel feedstocks. Specifically, we will:

• Use advanced imaging, nanoscience, and experimental facilities to develop the scientific foundation for enhanced soil carbon stabilization.
• Use models and experiments to characterize how climate change will affect soil carbon sequestration, and in particular management strategies, efficiency of sequestration, and security of pre-existing storage.

Use models and experiments to explore how biofuel feedstock production can be optimized for soil carbon storage, and what pitfalls to avoid.