| dc.description.abstract | Jati Muna merupakan salah satu jenis kayu yang banyak digunakan sebagai bahan baku mebel bermutu tinggi. Ketersediaan kayu jati Muna semakin berkurang dari tahun ke tahun akibat daur atau umur tebang yang terlalu lama (±50 tahun). Sejak satu dekade terakhir telah dikembangkan jati Muna cepat tumbuh yang lebih dikenal sebagai kayu jati inti karena dipapar dengan sinar gamma. Beberapa sifat dan karakteristik kayu jati inti sudah diteliti, namun mutu pertumbuhan pohon dan keawetan alami kayunya belum. Penelitian ini bertujuan mengevaluasi mutu pertumbuhan pohon jati inti umur 8 tahun dan mengkaji hubungan antara laju pertumbuhan pohon (perbedaan diameter setinggi dada/DBH) dengan beberapa karakteristik kayu.
Pohon contoh yang digunakan mewakili tiga tingkat laju pertumbuhan yang berbeda, yakni lambat, sedang, dan cepat tumbuh. Laju pertumbuhan ditetapkan berdasarkan rata-rata DBH dan standar deviasinya dari semua pohon yang terdapat dalam sebuah petak ukur berukuran 50 m x 50 m yang dibuat untuk mewakili seluruh areal tegakan. Mutu pertumbuhan pohon dievaluasi berdasarkan DBH, tinggi total (TT), tinggi bebas cabang (TBC), jumlah cabang, jumlah mata kayu lepas, serta tingkat kesilindrisan dan bentuk penampang lintang log. Dalam kaitannya dengan sifat dan karakteristik kayu, mutu pertumbuhan pohon dievaluasi berdasarkan juvenilitas dan variasi radial lebar riap tumbuh.
Masing-masing pohon contoh diambil disk setebal 6 cm dari ketinggian 130 cm di atas permukaan tanah dan log sepanjang 100 cm dari ketinggian 20 cm di atas permukaan tanah. Disk dijadikan contoh uji per segmen dari empulur ke kulit untuk pengukuran lebar riap tumbuh dan evaluasi juvenilitas, sedangkan log dikonversi jadi papan dan selanjutnya dijadikan contoh uji keawetan alami kayu yang mewakili bagian gubal, teras, dan peralihan. Juvenilitas dilakukan dengan dua pendekatan, yakni pengamatan langsung dan segmented regression model.
Hasil penelitian menunjukkan mutu pertumbuhan pohon jati inti umur 8 tahun tergolong sedang. Jumlah mata kayu lepas sedikit (4 buah per 4 m), rata-rata TBC > 4 m, 50% log yang dihasilkan silindris, lurus, dan bulat; namun pohon belum menghasilkan kayu dewasa dan bercabang banyak. Laju pertumbuhan tidak mempengaruhi mutu pertumbuhan pohon kecuali TT, TBC, dan mutu log; serta tidak mempengaruhi karakteristik kayu. Pohon yang laju pertumbuhnya lambat cenderung lebih rendah dan lebih pendek TBCnya, namun mutu log yang dihasilkan lebih baik (lebih silindris, lebih sedikit mata kayu lepas dan lebih bulat). Dari segi keawetan alami, kayu jati dari pohon yang laju pertumbuhannya cepat masuk ke dalam Kelas Awet I, sedangkan kayu-kayu dari pohon yang laju pertumbuhannya sedang dan lambat masuk Kelas Awet III. | id |
| dc.description.abstract | Muna teakwood is a species that is widely used as raw material for high-quality furniture. The availability of this wood is decreasing year by year due to the long cutting cycle (± 50 years). Since the last decade, fast-growing Muna teak, better known as superior Muna teak, has been developed. The seedlings was exposed to gamma rays. Several properties of this wood have been studied, but the quality of tree growth and natural durability level of wood have not been investigated yet. Therefore, the aims of this study were to evaluate the growth quality of the 8-year-old superior Muna teak trees and to examine the relationship between tree growth rate (difference in diameter at breast height/DBH) and wood characteristics.
There are three different growth rates of the tree, namely slow, medium, and fast growth, used as the sample. The growth rate of the tree is determined based on the average and standard deviation of DBH of all trees within a plot, 50 m × 50 m, which represents all stands. The quality of tree growth was evaluated based on DBH, total tree height (TT), clear bole height (TBC), and number of branches, number of loose knots, as well as the cylindrical level and cross-section shape of the log. In terms of wood characteristics, the quality of tree growth was evaluated based on juvenility level and growth ring width.
From each sample tree, a 6 cm thick disc from 130 cm above the ground and a 100 cm log from 20 cm above the ground were extracted. The disc is used to measure growth ring width, and juvenility level using the segmented samples from pith to bark, while the log is converted into boards and then reconverted into wood sample which represents sapwood, transition, and heartwood for natural durability evaluation. Juvenility level is carried out by two approaches i.e. direct observation and segmented regression model.
The results showed that the quality of tree growth was moderate. Number of loose knots was small (4 units per 4 m long log), average TBC was > 4 m, 50% of logs produced were cylindrical, straight, and round; however, the tree has not produced the mature wood yet and has many branches. The growth rate did not affect the quality of tree growth except for TT, TBC, and log quality, and also did not affect the characteristics of the wood. Slow-growth rate trees are shorter, have lower TBC, but their logs are more cylindrical, fewer loose knots, and rounded. In terms of natural durability, the superior Muna teakwood from fast-growth rate trees is classified as Durability Class I, while the woods from medium- and slow-growth rate trees are Durable Class III. | id |
