Forest Vegetation and the Nutritional Status of Soils on the Krakatau Islands, Indonesia

Although soils on the Krakatau Islands where the ecosystems were completely destroyed by the well known catastrophic eruptions in 1883 are virtually “immature” soils derived from volcanic ashes and scorias in an early weathering stage, the following soil characteristics supporting the luxuriant forest vegetation could be pointed out: high base saturation degree, high intensity of nutrient release and intermittent supply of fresh ashes from the active Anak Krakatau volcano. All these characteristics appear to be responsible for the efficient cycling of nutrient elements in the plant-soil system. Nutritional status of soils, i.e. amounts of exchangeable bases, available P and inorganic N, was relatively enriched on Rakata Besar where the soils are derived from volcanic ashes deposited in the form of pyroclastic flows in 1883 with little overlying volcanic ashes and scorias originating from the active Anak Krakatau volcano since 1929. Correlation study of the amounts of macronutrients with the total ABH (Are...