TITLE:
LiDAR Helps Differentiate Stand Health and Productivity Levels within a Northern Hardwood Forest
AUTHORS:
Christopher F. Hansen, Paul G. Schaberg, Allan M. Strong, Shelly A. Rayback, Gary J. Hawley
KEYWORDS:
Basal Area Increment, Crown Health, Foliar Nutrition, Tree Function, Tree Mortality
JOURNAL NAME:
Open Journal of Forestry,
Vol.10 No.1,
December
24,
2019
ABSTRACT: Light detection and ranging (LiDAR) data can provide detailed information
about three-dimensional forest structure. However, links between forest
structure and tree function have not been fully evaluated using LiDAR. We
assessed the relationship of LiDAR-derived structural categories to tree health
and productivity on 36 hardwood plots at the Hubbard Brook Experimental Forest,
New Hampshire, USA. We established nine plot replicates for each of four
LiDAR-based vegetation categories: 1) high crown and high understory closure; 2)
high crown and low understory closure; 3) low
crown and high understory closure; and 4) low crown and low understory closure. Ground-based measures of canopy structure, site, stand and individual
tree measures were collected on plots during summer 2012. Significant
differences among LiDAR categories were found for several response variables.
Lower basal area increment for sugar maple (Acer saccharum), decreased foliar nutrition for yellow birch (Betula alleghaniensis), and lower overall crown health were all associated with high
understory closure provided that overstory closure was also high. These results
suggest that LiDAR measures can be used to assess competitive interactions
between overstory and understory vegetation, and that LiDAR shows promise for
identifying stands with reduced health and productivity due to factors such as
competition or overstocking.