Quality of Standing Tree and Timber of Sengon of Private Forests

Abstract

Testing of standing tree quality doesn’t yet apply in private forest management in Indonesia, although the commonly used timber sales system is based on stumpage value. The study aimed to analyze the quality of standing trees and logs assortments of sengon in private forests planted with agroforestry patterns.  The study was conducted in the working area of a private forest cooperative in Probolinggo, which cooperated with the wood processing industry.   Testing of standing trees was conducted visually using tree parameters such as diameter at breast height, tree height, straightness of butt logs, and wood defects caused by pests, diseases, and natural factors.  Testing of the assortment quality was carried out based on the quality classes established by the partner wood industry.  Good logs assortments were used for plywood production, while the low logs were used for laminated boards.  The study showed that sengon trees have mostly small diameters (< 30 cm), commercial stem <50% of total height, straight butt logs, and fewer wood defects.  The most common wood defects were stem tumors and gall rust disease.  Most of the log assortments produced met the requirement for veneer raw materials, while the remainder were suitable for laminated boards.  Quality testing of standing trees needs to be developed for private forest management in Indonesia in the future.  This quality testing can help farmers and the wood industry in predicting the quality of log assortments and the economic value of the resulting logs.