An Unpiloted Aerial System (UAV) Light Detection and Ranging (LiDAR) Based Approach to Detect Canopy Forest Structure Parameters in Old-Growth Beech Forests: Preliminary Results

Abstract

Due to the increasingly rapid trend of biodiversity loss triggered by global changes and considering the critical role played by forests in conserving biodiversity, it is of great interest the study the structural attributes of natural forest stands. Understanding forest structure parameters, such as canopy height vertical variation, is crucial in acquiring information about natural forest dynamics. Recently, unpiloted aerial systems (UAV) have been used for mapping forest structure parameters. Among these, light detection and ranging (LiDAR) sensors are gaining attention. The main aim of this study is to test the feasibility of using UAV-based LiDAR surveys in detecting and mapping forest structure heterogeneity of primary old-growth beech forests. UAV survey has been conducted by means of the Zenmuse L1, equipped on board of the multirotor DJI Matrice 300 RTK in two small plots of the old-growth beech forest of Val Cervara, within the Abruzzo, Lazio, and Molise National Park in Italy. The acquired data have been processed to obtain the canopy height model (CHM). CHMs maps showed marked differences in canopy height spatial pattern between the two sample plots. Plot 1 showed a one-layered canopy density curve and a higher number of trees, while Plot 2 was characterized by a bimodal canopy layer with a lower number of trees. The proposed approach, even if still a first attempt, could be proposed as tool for mapping and monitoring old-growth beech forests.