Mapping Stand Age of global primary forests Using Remote Sensing Data

Gong Zhang, NASA ARC/ BAERI, yenite@gmail.com (Presenter)
Weile Wang, CSUMB&NASA/ARC, weile.wang@gmail.com
Ensheng Weng, Princton University, ensheng.weng@gmail.com
Sangram Ganguly, NASA ARC BAERI, sangramganguly@gmail.com
Sassan Saatchi, CALTECH/JPL, sassan.saatchi@jpl.nasa.gov
Yifan Yu, UCLA, yifan@atmos.ucla.edu
Michael White, Nature Press Group, mikew@cc.usu.edu
Ramakrishna R. Nemani, NASA ARC, rama.nemani@nasa.gov

Stand age distribution over large regions represents disturbance frequency and is a key factor in analysis and modeling of the terrestrial carbon cycle. Characterizing global forest stand age is still challenging in regions without abundant long-term inventory data. In this study, for the first time, we generated a stand age map for global primary forests based on remote sensing-derived AGB and net primary production. We built a theoretical framework by coupling a theoretical carbon accumulation function with the probability density functions of disturbance occurrences, thus linking biomass, net carbon fluxes into biomass, and disturbance frequency. We compared our stand age estimates against another stand age map based on interpolation of extensive inventory data in North American and found overall agreement but some important regional differences. Uncertainties in our approach are large. A sensitivity analysis of estimated stand age to variations in model parameters and input variables shows that the uncertainties in our approach can be quite signficant.

Presentation Type:  Poster

Session:  Poster Session 2-A   (Wed 11:00 AM)

Associated Project(s): 

• Related Activity or Previously Funded TE Activity

Poster Location ID: 87