%0 Research article
%T Semantic segmentation of forest stands using deep learning
%A Sandum, Håkon Næss
%A Ørka, Hans Ole
%A Tomic, Oliver
%A Næsset, Erik
%A Gobakken, Terje
%D 2026
%J Silva Fennica
%V 60
%N 1
%R doi:10.14214/sf.25010
%U https://silvafennica.fi/article/25010
%X Forest stands are the fundamental units in forest management inventories, silviculture, and financial analysis within operational forestry. Over the past two decades, stand borders have typically been delineated through manual interpretation of stereographic aerial images. This is a time-consuming and subjective process, which limits operational efficiency and introduces inconsistencies. Substantial effort has been devoted to automating the process, using various algorithms together with aerial images and canopy height models constructed from airborne laser scanning (ALS) data, but the manual interpretation remains the preferred method. Deep learning (DL) methods have demonstrated great potential in computer vision, yet their application to forest stand delineation remains unexplored in published research. This study presents a novel approach, framing stand delineation as a multiclass segmentation problem and applying U-Net-based DL-framework. The model was trained and evaluated using multispectral images, ALS data, and an existing stand map created by an expert interpreter. Performance was assessed on independent data using overall accuracy, a standard metric for classification tasks that measures the proportions of correctly classified pixels. The model achieved a pixel-level overall accuracy of 0.72. These results demonstrate the strong potential for DL-based stand delineation to be faster and more objective than manual methods. However, a few key challenges were noted, especially for complex forest environments. In these environments, model predictions showed over-segmentation and complex, irregular stand boundaries.