Linking Models and Data on Vegetation Structure: Implications for Predictions of North American Carbon Stocks and Fluxes

George Hurtt, UMD, gchurtt@umd.edu (Presenter)
Justin Fisk, UMD, fisk@umd.edu
Ralph Dubayah, UMD, dubayah@umd.edu
Steve Flanagan, UMD, sflanaga@umd.edu
Katelyn Dolan, UMD, dolan.katelyn@gmail.com
Michael Lefsky, CSU, lefsky@cnr.colostate.edu
Naiara Pinto, UMD, npinto@umd.edu
Hank Shugart, UVA, hhs@virginia.edu
Marc Simard, JL, marc.simard@jpl.nasa.gov

Scientists have long recognized the importance of vegetation structure in forest dynamics, but relevant data and models have generally not been available for large-scale applications. Now satellite missions utilizing lidar and radar technologies provide globally consistent data on vegetation structure, and new models track the dynamics of vegetation 3-D structure over large scales. Used together, these advances have the potential to revolutionize the initialization and testing of terrestrial models, and thereby reduce key uncertainties and improve model predictions of carbon cycle dynamics. Generally, both limited sampling and coarse resolution averaging lead to model initialization error, which in turn is propagated in subsequent model prediction uncertainty and error. In cases with representative sampling, sufficient resolution, and linear dynamics, errors in initialization tend to compensate at larger spatial scales. However, with inadequate sampling, overly coarse resolution data or models, and nonlinear dynamics, errors in initialization lead to prediction error. Here, we investigate the use of GLAS based forest structure products to initialize the ED model for estimates of carbon stocks and fluxes over North America. Focus is on quantifying the potential utility of various metrics, and the resolution and accuracy with which these measurements can/need to be made and model implemented.

Presentation Type:  Poster

Session:  Global Change Impact & Vulnerability   (Tue 11:30 AM)

Associated Project(s): 

• Dubayah, Ralph: Integrating Vegetation 3D Structure and Ecological modeling for Continental Scale Assessments of Biodiversity, Biomass and Disturbance ...details
• Hurtt, George: Using NASA Remote Sensing and Models to Advance Integrated Assessments of Coupled Human-Forest Dynamics for North America ...details

Poster Location ID: 215