Figure 3. Dendrogram showing clustering for 77 land use sampling sites compared based on the relative abundance of antibiotic resistance and class 1 integron-integrase genes. The hierarchical cluster analysis was performed using the ‘complete’ agglomeration method and the squared Euclidean distance for distance measures. The descriptor for each line is a code for each land use sampling site: Crop = cropland; For = forestland; InCrop = inactive cropland; Past = pastureland; Range = rangeland; Rec = recreational; and Res = residential. Nineteen of the original 96 sampling sites were not included in the analysis because genes were not detected at these sites.