The Degree of Stability of Rubber Stands (Hevea brasiliensis) in the Timber Estate Area of PT. Sylvaduta District Kembang Janggut, Kutai Kartanegara District East Kalimantan Province

Abstract

The development of Timber Estate (HTI) is one of the efforts to improve the welfare of the community's interests by considering the balance of the ecosystem. The development of rubber timber estate is expected to be a solution to the problems that hinder the current performance of HTI development, especially the problem of overlapping land tenure and the realization of planting. This is to maintain the fulfillment of the balance of environmental benefits, socio-cultural benefits, and economic benefits. The study's aims were: (1) to determine the percentage of the crown, total and branch-free height; and (2) to determine the stability value of rubber stands in the area of ​​P.T. Sylvaduta Corporation Timber Estate.  This research was conducted from April to May 2023 at P.T. Sylvaduta Corporation in Kembang Janggut District, Kutai Kartanegara Regency, East Kalimantan Province. namely in block A1 plot 1 to represent block A , Block E1 tile 3 to represent block E1 and lastly Block G3 tile 5 to represent block G3. A sampling of rubber plants in the area of ​​P.T. Sylvaduta Corporation used a purposive sampling of 150 plants.  Data Collection: (1) primary data: Diameter at Chest Height, Tree Height, and Crown length. And (2)secondary data include the following: (1) plant spacing; (2) the year of planting or the age of the plant, and (3) the general condition of the planting site was obtained from direct observations in the field and company documents. The research results show that : (1) the value of the degree of stability and percentage of the rubber plant canopy, namely 51.16% and 64.54%, is in the stable category; and (2) the use of a 3 x 6 m spacing using IRR 118 and PB260 clones had an average diameter at breast height of 20.9 cm, a total height of 10.62 m, a branch-free height of 3.81 m and a crown length of 6.82 m.