Land elevation and slope exposition impacts on rubber wood production volume under agroforestry system

¹ Graduate School of Forestry Science, College of Agriculture
² Graduate School of Environmental Science, College of Interdisciplinary
³ Department of Forestry, College of Agriculture
⁴ Study Program of Forestry, College of Agriculture Universtitas Lampung, Jalan Sumanteri Brojonegaro #1, Bandar Lampung- Indonesia 35145

^* Corresponding Author: christine.wulandari@fp.unila.ac.id

Abstract

As the senile phase due and causes depeleting latex productivity, the rubberwood stands can still be claimed as carbon sequestration under the REDD⁺ Scheme. This is also to maintain vegetation cover in protected forests, beside for fostering social forestry (HKm) sustainability as well. Nowadays the role of genetic and environment factors on latex production have widely revealed by some researchers, but lack on wood production especially for the effect of land elevation and slope exposition against solar beam radiation so need to research. Ordinary Least Square employed at 95% significant level, the respond variable was the volume wood production per tree, whereas the predictor were land elevation in an-100 m above sea level, land slope expositions that were decomposed into 4 categories with the reference of the compass direction in between 337⁰.30’ to 225.5⁰ follow needle clock’s direction while the three other directions were the westward, southwest ward, and northwest ward. Air humidity and temperature also incorporated to control model error. Data collected by surveying to 75 parcels at HKm area Mangga Joyo located in Way Kanan Regency. Parameter optimization used Minitab 16. The result suggest that wood volume average: (1) increase significantly by 0.02205m³ for every 100m higher elevation, but (2) decrease significantly by 0.21532 m³ which for westward land exposition compare to the eastward one.