PARENT SESSION
Poster Session #44: Remote Sensing and GIS.
Wednesday, August 7. Presentation from 5:00 PM to 6:30 PM. Exhibit Hall B & C, TCC

Small footprint LiDAR estimates of canopy gap structure in a Ponderosa pine forest .

Rowell, Eric^*,1,2, Vierling, Lee², Dykstra, Denise², Chen, Xuexia², ¹ Horizons, Incorporated, Rapid City, SD² South Dakota School of Mines and Technology, Rapid City, SD

ABSTRACT- Small footprint airborne LiDAR (Light Detection and Ranging) instruments provide high resolution surface/vegetation topography measurements by emitting a pulsed near infrared laser and measuring the return time and intensity of the reflected energy. Because portions of LiDAR pulses can penetrate forest canopies, these data hold promise for deriving forest canopy and sub-canopy structure over large areas. We acquired LiDAR data at 2m and 4m footprint resolution to examine their relationship to the gap structure of a Pinus ponderosa-dominated forest in the Black Hills of South Dakota. Ground measures of forest composition and structure were conducted at 107 100m² plots within the LiDAR acquisition area for comparison. Effective leaf area index (LAIe), a function of canopy gap fraction, was derived at each plot using a Li-Cor LAI-2000 instrument fitted with foreoptics to maximize overlap between ground and LiDAR measurements. We found a significant positive correlation between the percentage of LiDAR returns from the canopy and LAIe at both 2m resolution and 4m resolution. These results suggest that LiDAR may prove useful as independent measures of forest gap structure over large areas.

KEY WORDS: LIDAR, Pinus ponderosa, forest, structure