Tree and terrain measurements using small-footprint multiple-return airborne LIDAR data from mixed Douglas-fir forest in the Pacific Northwest

Terrain and canopy profiles were surveyed in stands of mixed Douglas-fir commercial forest near Bellingham, WA. Height, crown area and other characteristics of individual trees and vegetation features were measured in the field and compared with those made from LIDAR data. Terrain surfaces extracted from LIDAR data generally conformed with field surveys to within one meter. Height measurements were obtained on all isolated individual trees and 93% of canopy trees. Field measurements of both tree height and crown area of isolated individual trees were strongly related to the LIDAR data; R2 of 0.90 and 0.60 respectively. Deriving LIDAR measurements of trees in stands was more difficult, with an R2 of 0.69 for height and 0.36 for crown area.; Small-footprint multiple-return LIDAR offers potential for measurement of terrain and individual canopy trees in midrotation and mature stands. More precise measurements would be expected from a denser coverage of LIDAR pulses.