Investigating the Impacts of Tree Allometry on Lidar-Based Tree Aboveground Biomass Model Performance

Abstract

Airborne light detection and ranging (LiDAR) canopy height metrics are strong parameters for tree aboveground biomass (AGB) estimates. Since allometric models, in which tree diameter at breast height (DBH) and height are inputs, provide field AGB estimates in the LiDAR-AGB modeling processes, tree allometry is expected to impact the LiDAR-AGB model performance. The first objective of this study is to investigate how the tree height-DBH model fit impacts the LiDAR-AGB model performance. The second objective is to test how choices of allometric models for field AGB estimates influence the LiDAR-AGB model performance. A field data and simulation combined approach was employed. The primary findings showed that decline in the height-DBH model fit led to reduction in the LiDAR-AGB model performance. The secondary findings suggested that the LiDAR-AGB models developed from field AGB estimates based on both tree height and DBH outperformed models developed from field AGB estimates only based DBH.