Abstract: Numerous clustering algorithms are valuable in pattern recognition in forest vegetation, with new ones continually being proposed. While some are well-known, others are underutilized in vegetation science. This study compares the performance of practical iterative reallocation algorithms with model-based clustering algorithms. The data is from forest vegetation in Virginia (United States), the Hyrcanian Forest (Asia), and European beech forests. Practical iterative reallocation algorithms were applied as non-hierarchical methods and Finite Gaussian mixture modeling was used as a model-based clustering method. Due to limitations on dimensionality in model-based clustering, principal coordinates analysis was employed to reduce the dataset’s dimensions. A log transformation was applied to achieve a normal distribution for the pseudo-species data before calculating the Bray–Curtis dissimilarity. The findings indicate that the reallocation of misclassified objects based on silhouette width (OPTSIL) with Flexible-β (– 0.25) had the highest mean among the tested clustering algorithms with Silhouette width 1 (REMOS1) with Flexible-β (– 0.25) second. However, model-based clustering performed poorly. Based on these results, it is recommended using OPTSIL with Flexible-β (– 0.25) and REMOS1 with Flexible-β (– 0.25) for forest vegetation classification instead of model-based clustering particularly for heterogeneous datasets common in forest vegetation community data.

Key words: Classification, Heuristic clustering, Finite mixture, Forest ecosystems, Model-based clustering