Berkeley Lab scientists have expanded the capacity of a demographic vegetation model (FATES) to cycle nitrogen and phosphorus. This model is a component of Earth System Modeling, a tool that is used to make predictions and understand the current state of our planet’s water, carbon, and energy cycles.
*Note that in this diagram, N represents any nutrient, including nitrogen and phosphorus.
Image courtesy of Knox et al. (2024). Illustration by Diana Swantek, Lawrence Berkeley National Laboratory. Visualization of the dynamic interaction between differential carbon (C)and nutrient (N) storage and fine-root growth. A plant (left) with a proportionally more fine root will tend to have decreased carbon allocation and increased nutrient allocation, than a plant (right) with a proportionally less fine root. The algorithm presented here seeks to balance these allocations by modifying fine-root growth.
The Science
This research created numerical algorithms that represent how plants uptake mineralized nutrients from the soil, allocate nutrients to tissues and organs, and ultimately release it to litter for decomposition. Model output was compared with observations at Barro Colorado Island (BCI) in Panama. Of note, the relative supply of nutrients for each species of nitrogen and phosphorus, versus carbon in plant storage is directed to dynamically control the relative proportion of fine-roots, which enables interesting new plant competition and coexistence dynamics.
The Impact
This new model capacity is critical to representing realistic pan-tropical and global vegetation response in a changing climate, and the net land carbon sink in Earth System Models.
Contact
Ryan Knox
Lawrence Berkeley National Laboratory
rgknox@lbl.gov
Funding
Funding for this research was provided by the Department of Energy, Office of Science, Biological and Environmental Research (BER) Program, through the Next Generation Ecosystem Experiment – Tropics project.
Publications
Knox, R. G., Koven, C. D., Riley, W. J., Walker, A. P., Wright, S. J., Holm, J. A., et al. (2024). Nutrient dynamics in a coupled terrestrial biosphere and land model (ELM-FATES-CNP). Journal of Advances in Modeling Earth Systems, 16, e2023MS003689. https://doi.org/10.1029/2023MS003689.