Hydrological Performance of Pine Tree, Melinjo and Jackfruit for Rehabilitation of Catchment Area of Slope of Mt. Merapi, Indonesia after 2010 Eruption

Abstract

Estimation of the hydrological performance of individuals and communities trees of pine, melinjo (Gnetum gnemon L), and jackfruit very necessary. All the three species have a canopy, roots and stem characters with high potential to enter rainfall into the soil. This study aims to estimate the individual hydrological performance of trees based on through fall, interception, and stem flow and hydrologic performance of community tree based on run-off. The study was conducted on the slopes of Mount Merapi, at Sidorejo village, Klaten. The altitude is more than 500 m above sea level up to the area of Mount Merapi National Forest Sector II. The geographical position between 7 ° 34'15.12" - 7°37'08" S and 110 ° 27'39.6" - 110°29'31.7"E, in the rainy season of 2014. The study is a descriptive, the exploratory approach to the surveys and field measurements. The results showed that the hydrological performance of individual pine tree, jackfruit, and melinjo showed that of rainfall that fell most will escape through the canopy (± 62% -81%). The biggest interception percentage is on melinjo (19%) > pine (18%) > jackfruit (12%), while the percentage of stem flow from the highest to the lowest is jackfruit (26%) > melinjo (14%) > pine (1%). Community performance of pine trees, jackfruit, and melinjo shows that of rainfall that fell in the three communities, approximately 0.01 % to 2.07% will flow as a run-off. Through-fall plays an important role to fill the water catchment area, however, necessary measures to prevent or minimize run-off and increase the rate and infiltration capacity. Necessary to measure the amount of water stored in those third tree stands.

Keywords: Mt. Merapi eruption, hydrological performance, rehabilitation