We investigated changes in diversity and density of testate amoebae in epiphytes of trees in tropical montane rain forests of southern Ecuador. Local – microscale [height on tree trunk of 0 (base of tree trunk), 1 and 2 m; TH I, TH II and TH III, respectively] and regional – macroscale (forests at 1000, 2000 and 3000 m) changes were investigated. At the macroscale diversity and density of testate amoebae peaked at 2000 m. At the microscale diversity reached a maximum at TH I, whereas density reached a maximum at TH III. The percentage of empty shells at the macroscale was at a maximum at 2000 m and at the microscale at TH I, whereas the percentage of live cells was at a maximum at 3000 m and at TH III. The diversity of testate amoebae in epiphytes found in the present study was high (113 species). However, only two to nine species were dominant representing 54–85 percent of total living testate amoebae. The results suggest significant variations in density and diversity of testate amoebae at both the micro- and macroscale. However, for testate amoebae density the macroscale appears most important whereas changes in diversity are more pronounced at the microscale
