2023 CSDMS meeting-089
Phenology, Function, and Flash Drought: Investigating plant life stage and water use strategies during water stress events
Nicholas Corak, (he/him/his),Department of Physics, Department of Engineering, Wake Forest University Winston-Salem North Carolina, United States. firstname.lastname@example.org
Lauren Lowman, Department of Engineering, Wake Forest University Winston-Salem North Carolina, United States. email@example.com
Jason Otkin, Cooperative Institute for Meteorological Satellite Studies, Space Science and Engineering Center, University of Wisconsin-Madison Madison Wisconsin, United States. firstname.lastname@example.org
Trent Ford, Illinois State Water Survey, Prairie Research Institute, University of Illinois at Urbana-Champaign Urbana-Champaign Illinois, United States. email@example.com
Extreme drought events are becoming more frequent and severe. For example, since the flash drought of 2012 that ravaged the central United States, 2019 was the only year that has not experienced a billion dollar drought disaster. Examining how vegetation-atmosphere interactions change during extreme drought events can improve our understanding of how resilient different plants are at dealing with water stress during drought. We couple a prognostic phenology routine to a 1-D version of the Duke Coupled surface-subsurface Hydrology Model with dynamic vegetation (DCHM-V) to simultaneously simulate changes in plant life stage with water, energy, and carbon fluxes. The predictive phenology model simulates daily changes in canopy greenness and density based on the current meteorological conditions within the DCHM-V. We run the DCHM-V at a 4 km spatial resolution and hourly time step for pixels encompassing three AmeriFlux sites in the Midwestern United States. Modeling phenological changes and resulting land-atmosphere interactions allows us to investigate physical processes governing vegetation water use strategies in response to flash drought. Results show that vegetation under average water-use scenarios experience smaller reductions in growth as compared to isohydric or anisohydric water-use strategies. Transpiration dominates evapotranspiration with ample precipitation but is nearly cut in half during extreme drought resulting in reduced plant water use efficiency. These findings demonstrate the importance of incorporating dynamic phenological when investigating how vegetation modulates water, energy, and carbon under different water stress conditions, and have implications for improving predictions of drought impacts on the land surface.