3.2.1 Soil pH
The pH of the soils was relatively uniform (Figure 5), with the following mean pH in KCl values: Anak Krakatau (4.62), Sebesi (4.96), Rakata (5.60), and Pulau Panjang (5.63). The ΔpH (pH H2O – pH KCl) values were positive (mean of 1.1 unit). The continual eruption of Anak Krakatau had a profound effect on soil pH (H2O), resulting soils of Anak Krakatau have the lowest pH value. The variation within an island is noticeable with a general trend that soils in the lower elevation had a higher pH than those at a higher elevation.