B127-05
THE IMPORTANCE OF HYDRAULIC TRAITS TO TROPICAL FOREST DYNAMICS

Thursday, 17 December 2020: 04:16
Virtual
Chonggang Xu1, Bradley Christoffersen2, Ryan Knox3, Brett Wolfe4, Liang Wei5, Rutuja Chitra-Tarak6, Martijn Slot7, Rosie Fisher8, Lara M Kueppers9, Jeff Chambers3, Charlie Koven10 and Nathan McDowell11, (1)Los Alamos National Laboratory, Los Alamos, NM, United States, (2)University of Texas Rio Grande Valley, Edinburg, United States, (3)Lawrence Berkeley National Laboratory, Berkeley, CA, United States, (4)Louisiana State University, School of Renewable Natural Resources, Baton Rouge, United States, (5)Los Alamos National Laboratory, Earth and Environmental Sciences Division, Los Alamos, NM, United States, (6)Los Alamos National Laboratory, Earth and Environmental Sciences, Los Alamos, NM, United States, (7)Smithsonian Tropical Research Institute, Balboa, Panama, (8)National Center for Atmospheric Research, Boulder, CO, United States, (9)University of California Berkeley, Energy and Resources Group, Berkeley, CA, United States, (10)Earth Sciences Division, Lawrence Berkeley National Laboratory,, Berkeley, CA, United States, (11)Pacific Northwest National Laboratory, Richland, WA, United States
Recorded Presentation
Abstract:
Vegetation plays a key role in global carbon cycles and thus is an important component within Earth system models (ESMs) that project future climates. A recent trend for ESM vegetation modeling is to incorporate size- and succession-stage-structured demographic models. These models make it feasible for more realistic representation of key processes that control vegetation dynamics. In this study, we reported a new hydrodynamics (HYDRO) model within the functionally assembled terrestrial ecosystem simulator (FATES-HYDRO). The HYDRO model is built on the size and canopy structured representation within FATES and is expected to better capture the control of hydraulic traits in both vegetation dynamics and carbon/water fluxes. In this study, we conducted a global sensitivity analysis to better understand the hydraulic trait control on tropical forest dynamics at Barro Colorado Island, Panama. We assembled statistical distributions of plant hydraulic traits of stomata, leaves, stems, and roots, determined the best-fit theoretical distribution for each trait, and linked these based on taxonomically-standardized species names to generate a rank correlation matrix, which quantified the degree of interspecific (between-species) trait-trait coordination. Our analysis showed that hydraulic traits that determine the soil-root connection and stomatal control are more important for carbon and water fluxes during dry periods, while hydraulic traits that determine the whole tree conductance are more importance for wet periods. Our analysis suggests that hydraulic traits could play an important role in carbon and water fluxes and vegetation dynamics in tropical forests, but that the relative importance of different hydraulic traits shifts seasonally. Therefore, further measurements to capture the hydraulic control on stomata, root-soil interface and whole tree resistance could improve our prediction of future tropical forests within ESMs.
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