Keywords: Volcanic soils; andosols; geochemistry; discriminant analysis; tephra; Indonesia
INTRODUCTION
The late Mt. Krakatau erupted in May-August 1883 and had sterilised all soil and vegetation in the islands. Much has been investigated on the vegetation and volcanic activities of Krakatau (R. J. Whittaker, Bush, & Richards, 1989); however, the soils of Krakatau are less studied. As the age of the parent material is known precisely, and the area is less influenced by human activities, examining soils of Krakatau could provide an insight into the first stages of weathering and pedogenesis in tropical volcanic regions. The study of volcanic materials and their weathering products can inform us on the nutrient supply, and impacts on existing soils (Alloway, Andreastuti, Setiawan, Miksic, & Hua, 2017; Anda, 2016; Dian Fiantis, Ginting, Nelson, & Minasny, 2019). Understanding the triggers and controls of soil formation will lead to better sustainable use and made us aware of the fragility of soil formation and avoid degradation.