Characterization of structural changes in coffee plants after mechanized harvesting using airborne LiDAR

Abstract

The three-dimensional representation provided by the light detection and ranging sensor (LiDAR) offers possibilities for analyzing the structure of the coffee canopy, especially under conditions in which mechanized harvesting may be associated with changes in canopy organization. This study aimed to characterize structural changes in the coffee canopy associated with mechanized harvesting using metrics derived from LiDAR point clouds. LiDAR surveys were conducted before and after harvesting in an experimental Arabica coffee plot, followed by point cloud preprocessing, surface model generation, planting row segmentation, and extraction of structural metrics by segment. Subsequently, the data were analyzed using paired statistics, principal component analysis (PCA), and k-means clustering, in addition to the generation of vertical and transverse canopy profiles. The results indicated reductions in metrics associated with height, structural occupancy, and apparent canopy volume, accompanied by increased canopy openness and a greater relative presence of returns in lower strata. Heterogeneous spatial patterns of alteration were also identified along the planting rows, with different intensities and directions of structural response among segments. Overall, the profiles revealed vertical redistributions of the canopy after harvesting. Thus, this study contributes to expanding the understanding of how mechanized harvesting may be reflected in the structural organization of coffee plants and reinforces the potential of LiDAR as a support tool for spatial and vertical analysis of the crop.