AGRO-ECOSYSTEM CHANGES ON THE SOUTHERN PARTS OF MERAPI VOLCANO AFTER 5 YEARS ERUPTION
Abstract
This study aimed to determine changes in the agro-ecosystem at the southern parts of Merapi Volcano after the eruption of 2010. The field research was conducted using a survey method that is based on the landscape analysis. The smallest analysis unit for changing in agro-ecosystem is geomorphologic unit of merapi volcano. Purposive sampling method was done to determine 20 sites as representing of the upper, middle and lower slopes of Merapi Volcano. The parameters observed climate (rainfall and temperature), the type of agro-ecosystem, species of plants, type of mineral and soil type. Based on the climatological data indicated that the annual rainfall average of this area 1810 mm/yr or B type according Smith-Ferguson classification. The recorded lowest temperature was 15 oC at the night and the highest one of 28 °C during the day. Based on field observations obtained that at the upper slope area was a forest agro-ecosystem dominated by Accasia docurens that grow naturally. At the middle slope area was a mixture agro-ecosystem compose of a perennial crops, such as accasia docurens, albizia, bamboo, teak, grass, etc. At the lower slopes area was also a mixture agro-ecosystem compose of forest crops and food crops that grow naturally and planted by farmers, such as bamboo, jackfruit, mango, rambutan, banana, snakeskin fruit etc. The Merapi volcano eruption in 2010 led to supplies a volcanic materials contains a lot of weathereable primary minerals such as albite, anorthite, opaque. The volcanic material is rich in macronutrients such as P2O5 (655 mg/kg), CaO (17300 mg/kg), MgO (73.7 mg/kg), K2O (4930 mg/kg), and micronutrients such as ZnO (35.8 mg/kg), Mn (414 mg/kg), CuO (25.5 mg/kg). Soil Orders observed were Entisols, Inceptisol and andisols with soil morphology dominated by polygenesis.