Estimating forest growth using canopy metrics derived from airborne laser scanner data

Mean tree height (hL), basal area (G), and volume (V) were regressed against the laser-derived variables to predict corresponding values of hL, G, and V based on the 1999 and 2001 laser data, respectively. Forest growth was estimated as the difference between the 2001 and 1999 estimates. Laser data were able to predict a significant growth in all the three biophysical variables over the 2-year period. However, the accuracy of the predictions was poor. In most cases the predictions were biased and the precision was low. Finally, several key issues of particular relevance to laser-based monitoring of forest growth are discussed.