This study proposes PlantViT, a Vision Transformer (ViT)-based framework for high-precision vegetation classification by integrating hyperspectral imaging (HSI) and Light Detection and Ranging (LiDAR) data. The dual-branch architecture optimizes feature fusion across spectral and spatial dimensions, where the LiDAR branch extracts elevation and structural features while minimizing information loss and the HSI branch applies involution-based feature extraction to enhance spectral discrimination. By leveraging involution-based feature extraction and a Lightweight ViT (LightViT), the proposed method demonstrates superior classification performance. Experimental results on the Houston 2013 and Trento datasets show that PlantViT achieves an overall accuracy of 99.0% and 97.4%, respectively, with strong agreement indicated by Kappa coefficients of 98.7% and 97.2%. These results highlight PlantViT’s robust capability in classifying heterogeneous vegetation, outperforming conventional CNN-based and other ViT-based models. This study advances Unmanned Aerial Vehicle (UAV)-based remote sensing (RS) for environmental monitoring by providing a scalable and efficient solution for wetland and forest ecosystem assessment.