Cluster analysis based on Jaccard dissimilarity of absence and presence data of land snail species composition in 33 standard plots in Penang Hill, Penang Island, Peninsular Malaysia. Three main clusters were identified: Cluster 1, comprising two sub-clusters in which almost all plots in undisturbed and disturbed forests were grouped; Cluster 2, comprising all plots in orchards and one plot in a disturbed forest patch in the botanical garden; and Cluster 3, comprising three undisturbed plots.