LAJU PERTUMBUHAN, SIFAT ANATOMI DAN SIFAT FISIKA KAYU JABON MERAH (Anthocephalus macrophyllus) YANG TUMBUH DI KABUPATEN BANGGAI SULAWESI TENGAH

Bahidin Laode Mpapa S.Hut, Dr. Ir. Sri Nugroho Marsoem, M. Agr

2012 | Tesis | S2 Ilmu Kehutanan

Hutan merupakan satu anugerah yang dapat menjadi salah satu solusi perubahan iklim, karena hutan bisa menyerap karbon dioksida (CO2) dari atmosfer. Jenis-jenis tanaman asli lokal (indigenous) yang beragam perlu di jaga dan dilestarikan. Salah satu jenis asli lokal yang memiliki banyak manfaat yaitu jabon merah. Ditengah kelangkaan dan keterbatasan bahan baku saat ini, jenis jabon merah dapat menjadi salah satu alternatif untuk memenuhi kebutuhan masyarakat dan industri kayu nasional. Namun, untuk menuju kearah pemenuhan bahan baku tersebut perlu pembangunan hutan tanaman secara luas. Pembangunan hutan tanaman jabon dan pemanfaatan produksi kayunya memerlukan pengetahuan tentang laju pertumbuhan, pembentukan kayu dan sifat-sifat kayunya. Tujuan dari penelitian ini adalah mengetahui laju pertumbuhan, sifat anatomi pada periode pertumbuhan bulan Oktober 2010 – Februari 2011 dipantau dengan metode penusukan dan variasi sifat fisika kayu jabon merah. Analisis dan rancangan yang digunakan adalah analisis koefisien korelasi sederhana (Pearson Correlation) dan rancangan acak lengkap ulangan sama dan ulangan tidak sama dengan klasifikasi satu arah (One Way Anova) Hasil penelitian menunjukkan bahwa rata-rata riap diameter pohon jabon merah yaitu 5,05 cm/tahun dengan kisaran 0,15 – 0,67 cm. Riap diameter pohon jabon merah tidak berkorelasi nyata dengan curah hujan dan suhu pada periode Februari 2010 – Maret 2011. Hasil pengamatan anatomi menunjukkan bahwa Rerata proporsi sel pembuluh berkisar 8,49 – 13,30 %; serabut 46,44 – 51,11 %; parenkim 14,95 – 17,90 % dan jari-jari 21,71 – 25,82 %. Rerata panjang serat berkisar 1,75 – 1,91 mm, diameter serat 29,58 – 35,69 μm, diameter lumen 22,46 – 26,70 μm dan tebal dinding serat 7,12 – 8,85 μm. keseluruhan proporsi sel dan dimensi sel kayu jabon merah tidak berpengaruh nyata, demikian pula dengan hubungan antara proporsi sel, dimensi sel dengan curah hujan tidak menunjukkan korelasi nyata pada semua periode pertumbuhan (Oktober 2010 – Februari 2011) meskipun di peroleh nilai korelasinya relatif besar pada proporsi pembuluh, diameter serat dan diameter lumen. Hasil pengukuran sifat fisika Kayu jabon merah memiliki kisaran kadar air segar 74,38 – 92,05%, kering udara 16,58 – 18,57 %, berat jenis segar 0,31 – 0,35, berat jenis kering udara 0,32 – 0,37, berat jenis kering tanur 0,33 – 0,39, penyusutan tangensial 4,67 – 5,17 %, penyusutan radial 2,12 – 2,59 %, penyusutan longitudinal 0,10 – 0,18 %, rasio T/R penyusutan 2,17, pengembangan tangensial 5,08 – 5,80 %, Pengembangan radial 2,47 – 3,03 %, pengembangan longitudinal 0.19 – 0,33%, dan rasio T/R pengembangan 2,09. Sifat fisika kayu jabon merah yang memberikan pengaruh berbeda nyata hanya terdapat pada berat jenis, selebihnya tidak berbeda nyata. Diperkirakan kayu jabon merah masih dalam periode juvenil.

A forest is a gift that can be one of solutions to climate change, because a forest can absorb carbon dioxide (CO2) from the atmosphere. The variety of local indigenous plants needs to be preserved. One of the local indigenous species having many benefits is red jabon. Amid the current scarcity and limitations of raw materials, species red jabon may be one alternative to meet the needs of the community and the national timber industry. However, for that purposes of fulfilling the necessary raw materials, forest plantation development should be widely implemented. The development of jabon forest plantation and the utilization of its wood production require the knowledge of its growth rate, wood formation and wood properties. The purpose of this study was to determine the rate of growth, the anatomy properties during the growth period of October 2010 - February 2011 which was monitored using the pinning method and identify the variation of physical properties of red jabon wood. The analysis used was a simple correlation coefficients analysis (Pearson Correlation) and design used was completely randomized design with equal and different repetition with one-way classification (One Way Anova). The results showed that the average diameter increment of red jabon tree was 5.05 cm / year with a range from 0.15 to 0.67 cm. Red jabon tree diameter increment had no significant correlation with the actual rainfall and temperature in the period of February 2010 - March 2011. Anatomy observations indicated that the mean proportion of vascular cells ranged from 8.49 to 13.30%; fibers ranged from 46.44 to 51.11%; parenchyma ranged from 14.95 to 17.90% and the rays ranged from 21.71 to 25.82%. The mean fiber length ranged from 1.75 to 1.91 mm; fiber diameter ranged from 29.58 to 35.69 μm; luminna diameter ranged from 22.46 to 26.70 μm; and fiber thick wall ranged from 7.12 to 8.85 μm. Overall cell proportion and dimension in red jabon wood had no significant effect. In addition, the proportion of cells, cell dimension and rainfall showed no significant correlation in all the growth periods (October 2010 - February 2011), although the correlation values obtained for proportion vessels, fiber diameter and luminna diameter are relatively high. The results of measurements of physical properties of red jabon wood indicated that the green moisture content ranged from 74.38 to 92.05%, the air dry moisture content ranged from 16.58 to 18.57%, the green basic density ranged from 0.31 to 0.35; air dry basic density ranged from 0.32 - 0.37; the oven dry basic density ranged from 0.33 to 0.39; the tangential shrinkage ranged from 4.67 to 5.17%; the radial shrinkage ranged from 2.12 to 2.59%; the longitudinal shrinkage ranged from 0.10 to 0.18%; the ratio T/R shrinkage was 2.17; the tangential swells ranged from 5.08 to 5.80%; the radial swells ranged from 2.47 to 3.03%; the longitudinal swells ranged from 12:19 - 0.33%; the T/R ratio swells was 2.09. The physical properties of red jabon wood which had significantly different influence was only its basic density, whereas the other properties were not significantly different. It was estimated that the red jabon wood was still in its juvenile period.

Kata Kunci : laju pertumbuhan, pembentukan kayu, metode penusukan, kayu jabon merah, sifat anatomi, sifat fisika