Characterization of Andosols in Yakushima Island

Research on Yakushima Island reveals that Andosols derived from volcanic ash exhibit distinct chemical and mineralogical properties depending on their ecological context. Soils under evergreen broad-leaved forests show high concentrations of acid oxalate-extractable aluminum (Alo) and silicon (Sio), alongside low iron (Fe) ratios, indicating a warmer climate with less severe leaching compared to soils under coniferous or grassland ecosystems. All studied pedons were classified as Kuroboku soils (USCSJ 2nd) and Andosols (WRB). Notably, mountainous Andosols lack allophanic horizons due to intense rainfall (>10,000 mm/year), which inhibits allophane formation through Al leaching, humus complexation, and vermiculite interlayer incorporation. These findings highlight the interplay between climate, vegetation, and soil development in shaping Andosol properties on Yakushima Island.

Eguchi, T., & Tamura, K. (2012). Characterization of Andosols in Yakushima Island. Soil Science and Plant Nutrition, 58(1), 52–64. https://doi.org/10.1080/00380768.2011.653691