Geoecological-Based Strategy for Ecosystem Improvement in Volcanic Zones: A Preliminary Study from Jurang Jero Area, Merapi National Park

Abstract

Mount Merapi, one of Indonesia’s most active volcanoes, has repeatedly altered surrounding river ecosystems through frequent eruptions, with the 2010 event producing over 140 million cubic meters of pyroclastic material. This preliminary study aims to analyze the geoecological dynamics of the Jurang Jero sector in Merapi National Park, which has experienced severe impacts on river morphology, sedimentation, water quality, and riparian vegetation. A desk study approach was employed, synthesizing secondary data that included geological and hazard maps, remote sensing imagery, hydrological records, and published scientific reports. Findings indicate that lahar-induced sedimentation after 2010 resulted in aggradation, channel widening, and a reduction in river capacity, with some sabo dams quickly reaching their limits. Water quality deteriorated due to extremely high suspended solids, increased turbidity, and elevated heavy metals, although these effects were partly temporary. Riparian vegetation suffered extensive damage, followed by natural succession dominated by invasive species such as Acacia decurrens, which hinders native regeneration. Nevertheless, signs of ecological recovery have emerged, as evidenced by the presence of pioneer species and the implementation of rehabilitation programs. This study highlights the need for a geoecology-based adaptive conservation strategy that integrates river morphology rehabilitation, sediment management, water quality improvement, and riparian vegetation restoration while involving local communities. The proposed framework provides a conceptual basis for future field research and practical river ecosystem management in volcanic landscapes.