Biomass Estimation of Douglas-fir Stands Using Airborne LiDAR Data

Biomass is an important parameter not only for carbon cycle modeling, but also for supporting land management operations (e.g. land use policy, forest fire management). Various remote sensing data have been utilized for biomass estimation, especially in forested areas. LiDAR (Light Detection And Ranging) instruments measure the vertical structure of forests and thus hold great promise for remotely sensing the quantity and spatial organization of forest biomass. Considering the influence of vegetation reflectance, canopy crown shape, canopy laser penetrability and laser density on the emission and propagation of laser energy, we developed a geometric model to simulate the spatial distribution of laser returns in Douglas fir canopy. We then estimated biomass of individual trees by applying this model on airborne LiDAR data in a rangeland watershed in Southern Idaho. We also evaluated LiDAR-derived biomass estimates with field measurements.