Volcano Eruption and Invasion of Acacia decurrens (Wendl.) wild. in Mount Merapi National Park

Abstract

Mount Merapi located in Mount Merapi National Park is one of the major active volcanoes on the Island of Java. The type of eruption is characterized by the collapse of lava dome at the summit generating a huge pyroclastic flows. The last eruption occurred in 2010 and caused severe damage to the surrounding vegetation. After the eruption, Acacia decurens grew to dominate in all areas affected by the eruption. The purpose of this research was to investigate the influence of Mt Merapi eruption on the density and distribution of A. decurrens. The study was conducted at three locations: Cangkringan and Kemalang which were affected by the eruption and Selo as a comparison because it was not affected by the eruption. The -result showed that the population of A. decurrens in Cangkringan was higher than in Selo. The important value indexes (IVI) showed that A. decurrens are more dominant in Cangkringan and Kemalang than Selo. Based on Morisita index, at Cangkringan and Kemalang A. decurrens saplings was distributed in a clump while at Selo in a random pattern. The high density of A. decurrens indicated that the erruption of Mt. Merapi affects invasion of A. decurrens.