Application of UAV LiDAR Data to Assess the Relationship Between Forest Canopy Structure and Understory Light Environment in the Son Tra Nature Reserve, Da Nang

Abstract

The three-dimensional (3D) structure of forest canopies plays a critical role in determining habitat
conditions for living organisms, in which the heterogeneous distribution of understory light is a key factor
directly influencing forest regeneration and biodiversity. However, conventional field surveys and ground-based
imaging methods are limited in spatial coverage, posing challenges for comprehensive ecosystem monitoring.
This study introduces a methodological framework utilizing LiDAR data acquired from unmanned aerial vehicles
(UAVs) to quantify canopy structural heterogeneity and model the relationship between 3D canopy structure and
light distribution. The workflow includes collecting high-density LiDAR point clouds, generating digital terrain,
surface, and canopy height models (DTM, DSM, CHM), and calculating canopy height and canopy cover metrics.
Statistical analyses are then conducted to evaluate the relationships between canopy height, canopy surface
structure, and understory light conditions. The results demonstrate that UAV-based LiDAR is an effective tool
for high-resolution forest structural mapping, providing valuable potential for applications in sustainable forest
management.