Cale Galloway, Hong-Bing Su, Thad Wasklewicz
East Carolina University, Greenville, NC, USA, firstname.lastname@example.org
The current study aims to obtain detailed 3-D distributions of vegetation area density (VAD) and the architecture of dominant trees in a study plot in Howland Research Forest, Maine, USA. This information is critical to improving 3-D modeling of the aerodynamic interactions between turbulent gusts and group tree-sways in an ongoing NSF funded collaborative research project. An exploratory experiment was carried out in the summer of 2010 in which a Leica Geosystems C10 scanner was deployed at 6 different scan locations encompassing approximately 1,405 m2. The scanning resolution was 1 cm x 1 cm in both horizontal and vertical directions at a range of 30 m. A voxel-based technique was used to estimate the vertical profiles of vegetation area density (VAD) and vegetation area index (VAI). Corrections were made to reduce the shadow effect and to account for leaf inclination distribution. Our estimates of VAI are compared with previous estimates using indirect approaches for the Howland Forest. The effects of scan position, reducing the shadowing effects are also discussed. Results will be used to guide future experimental design in a planned full-scale scanning of the entire study plot.
Keywords: Terrestrial Laser Scanning, Vegetation Area Density, Vegetation Area Index, Forest-Atmosphere Interaction, Howland Forest