Distribution of Available Silicon of Volcanic Ash Soils in Jeju Island

Figure 3

Comparison of available Si content in topsoils of non-Andisols and Andisols on Jeju Island according to land use types (a) and elevation (excluding upland soils) (b). Error bars indicate the standard error. Shown are the values of Mann–Whitney U test analyses. Different letters above bars within the same soil type indicate significant differences among the elevations, as determined by Tukey’s HSD test computed with ranks after Kruskal–Wallis one-way ANOVA on ranks. For all analyses, a value of 0.05 was considered significant.

(a)

(b)