Simpulan
Perlakuan penjarangan dan pelebaran jarak bebas naungan secara signifikan menurunkan tutupan tajuk serta meningkatkan diameter dan TBC, sementara tinggi total hanya dipengaruhi oleh penjarangan. Perlakuan penjarangan dan
Komponen Kimia JBN 8 m JBN 10 m JBN 12 m JBN 8 m JBN 10 m JBN 12 m Gubal 31.16 31.73 32.57 31.63 31.59 30.83 Teras 34.23 33.26 32.92 33.87 33.86 33.92 Gubal 68.14 69.76 69.43 68.95 68.53 69.46 Teras 66.77 68.12 68.81 67.59 67.65 67.68 Gubal 40.65 42.51 42.87 41.30 41.63 42.48 Teras 40.44 42.48 40.60 40.77 41.80 41.38 Gubal 27.49 27.26 26.56 27.65 26.90 26.98 Teras 26.33 25.64 28.22 26.81 25.86 26.30
Keterangan: JBN = Jarak bebas naungan Holoselulosa (%)
Alfa Selulosa (%)
Hemiselulosa (%)
Tanpa Penjarangan Penjarangan
18
pelebaran jarak bebas naungan secara nyata menurunkan BJ, kerapatan, dan KA kering udara serta mempengaruhi penyusutan pada ketiga arah susutnya. MOE, MOR, kekuatan tekan sejajar serat, kekuatan belah, dan kekerasan sisi secara nyata juga mengalami penurunan dengan adanya penjarangan dan pelebaran jarak bebas naungan.
Penjarangan dan pelebaran jarak bebas naungan cenderung menurunkan persentase kayu teras serta menurunkan panjang serat dan tebal dinding serat namun meningkatkan diameter serat dan diameter lumennya. Secara umum perlakuan penjarangan dan pelebaran jarak bebas naungan menurunkan kadar ekstraktif pada kayu teras, namun meningkatkan kadar ekstraktif pada kayu gubal dan kadar abu. Kadar lignin, holoselulosa, alfa selulosa, dan hemiselulosa tidak dipengaruhi secara nyata oleh perlakuan penjarangan dan pelebaran jarak bebas naungan
Saran
Berdasarkan hasil penelitian, lebar jalur bebas naungan yang optimal pada sistem TPTJ agar diperoleh pertumbuhan serta kualitas kayu yang baik yaitu tidak lebih dari 10 m. Perlu dilakukan penelitian terkait intensitas penjarangan yang tepat agar kualitas kayu tidak mengalami penurunan yang signifikan.
DAFTAR PUSTAKA
Abohassan A, Tewfik SFA, Wakei AOE. 2010. Effect of thinning on the above ground giomass of (Conocarpus erectus L.) trees in the western region of Saudi Arabia. JKAU: Met., Env. & Arid Land Agric. Sci. 21 (1): 3-17. Al-Mefarrej HA, Abdel-Aal MA, Nasser RA, Shetta ND. 2011. Impact of initial
tree spacing and height level on chemical compotition of Leucaena leucocephala trees grown in Riyadh region. Wood Applied Sciences Journal 12 (7): 912-918.
Basri E, Rulliaty S. 2008. Pengaruh sifat fisik dan anatomi terhadap sifat pengeringan enam jenis kayu. Jurnal Penelitian Hasil Hutan 26 (3): 253- 262.
Berberovic A, Milota MR. 2012. Impact of wood variability on the drying rate at different moisture content levels. Forest Pruducts Journal 61 (6): 435-442. Brown PL, Doley D, Keenan RJ. 2004. Stem and crown dimensions as predictors
of thinning respones in a crowded tropical rainforest plantation of Flindersia brayleyana F. Muell. Journal of Forest and Management 196 (2004): 379-392.
Browning BL. 1967. Methods of Wood Chemistry. New York: Interscience Publ. Cao T, Valsta L, Härkönen S, Saranpää, Mäkelä A. 2008. Effects of thinning and
fertilization on wood properties and economic returns for norway spruce. Journal of Forest Ecology and Management 256 (2008): 1280-1289.
19 Darmawan W, Alipraja I. 2010. Karakteristik aus pisau pengerjaan kayu karena pengaruh ekstraktif dan bahan abrasif yang terdapat pada kayu dan komposit kayu. Jurnal Ilmu dan Teknologi Hasil Hutan 3 (1): 32-37.
DeBell JD, Lachenbruch. 2009. Heartwood/sapwood variation of western redcedar as influenced by cultural treatments and position in tree. Journal of Forest Ecology and Management 258 (2009): 2026-2032.
Ekeberg D, Flaete PO, Eikenes M, Fongen M, Andresen CFN. 2006. Qualitative and quantitative determination of extractives in hearthwood of scots pine (Pinus sylvestris L.) by gas chromatography. Journal of Chromatography A. 1109 (2006): 267-272.
Gao H, Zhang L, Liu S. 2011. Comparison of KP pulping properties between hearthwood and sapwood of Cedrus deodora (Roxb.). G. Don. Applied Mechanics and Materials 55-57 (2011): 1778-1784.
Gartner BL. 2002. Sapwood and inner bark quantities in relation to leaf area and wood density in douglas-fir. IAWA Journal 23 (3): 267-285.
Goncalves JLM, Stape JL, Laclau JP, Smethurst P, Gava JL. 2004. Silvicultural effects on the productivity and wood quality of eucalypt plantations. Journal of Forest Ecology and Management 193 (2004): 45-61.
Haroen WK, Dimyati F. 2006. Sifat kayu tarik, teras dan gubal Acacia mangium terhadap karakteristik pulp. Jurnal BB 41(1): 1-7.
Huang S, Wang BJ, Lu J, Dai C, Lei Y, Sun X. 2012. Charaterizing changbai larch trough veneering. Part 1: Effect of stand density. Journal of Bio Research 7 (2): 2444-2460.
Jyske Tuula. 2008. The effects of thinning and fertilisation on wood and tracheid properties of norway spruce (Picea abies) – The results of long-term experiments. [Dissertation]. Helsinki: Faculty of Agriculture and Forestry University of Helsinki.
Kammesheidt L, Dagang AA, Schwarzwäller W, Weidelt HJ. 2003. Growth patterns of dipterocarps in treated and untreated plots. Journal of Forest Ecology and Management 174 : 437-445.
Kiaei M, Samariha A. 2011. Fiber dimensions, physical and mechanical properties of five important hardwood plants. Indian Journal of Science and Technology 4 (11) 1460-1463.
Kord B, Kialashaki A, Kord B. 2010. The within-tree variation in wood density and shrinkage, and their relationship in Populus euramericana. Turk J. Agric. For 34 (2010): 121-126.
Korkut DS, Korkut S. 2008. Determination of the shear and cleavage strengths of european hophornbeam (Ostrya carpinifolia Scop.) wood. Journal of Science and Technology 2 (1): 131-137.
Latorraca JFC, Dunisch O, Koch G. 2011. Chemical composition and natural durability of juvenile and mature heartwood of Robinia pseudoacacia L. An Acad Bras Cienc 83(3): 1059-1068.
Leonardon M, Altaner CM, Vihermaa L, Jarvis MC. 2009. Wood shrinkage: Influence of anatomy, cell wall architecture, chemical composition and cambial age. Eur. J. Wood Prod (2009) 00: 1-8.
Lukmandaru G. 2009. Sifat kimia dan warna kayu teras jati pada tiga umur berbeda. Jurnal Ilmu dan Teknologi Kayu Tropis 7 (1): 1-7.
20
Lundgren C. 2004. Cell wall thickness and tangential and radial cell diameter of fertilized and irrigated norway spruce. Silva Fennica 38(1): 95–106.
_________, 2004. Microfibril angle and density patterns of fertilized and irrigated norway spuce. Silva Fennica 38(1): 107-117.
Mawazin, Suhaendi H. 2011. Kajian pertumbuhan tanaman pada sistem silvikultur tebang pilih tanam indonesia intensif (TPTII) di Kalimantan Tengah. Jurnal Penelitian Hutan dan Konservasi Alam 8 (3) : 253-261.
Mindawati N, Tiryana T. 2002. Pertumbuhan jenis pohon Khaya anthotheca di Jawa Barat. Bulletin Penelitian Hutan No. 632: 47-58.
Morais MC, Pereira. 2012. Variation of extractives content in hearthwood and sapwood of Eucalyptus globulus trees. Wood Sci. Technol 46 (2012): 709- 719.
Nawrot M, Pazdrowski W, Szymanski M. 2008. Dynamics of heartwood formation and axial and radial distribution of sapwood and heartwood in stems of european larch (Larix decidua Mill.). Journal of Forest Science 54 (9) : 409-417.
Pamoengkas P. 2006. Kajian aspek vegetasi dan kualitas tanah sistem silvikultur tebang pilih tanam jalur (Studi kasus di areal HPH PT. Sari Bumi Kusuma, Kalimantan Tengah. [Disertasi]. Bogor (ID): Institut Pertanian Bogor. _________, Prayogi J. 2011. Pertumbuhan meranti merah (Shorea leprosula Miq)
dalam sistem silvikultur tebang pilih tanam jalur (Studi kasus di areal IUPHHK-HA PT. Sari Bumi Kusuma, Kalimantan Tengah). Jurnal Silvikultur Tropika 02 (1) : 9-13.
Pandit IKN, Rahayu IS. 2007. Ultra-struktur kayu damar (Agathis lorantifolia Salisb.) dalam hubungannya dengan sifat fisis kayu. Jurnal Ilmu dan Teknologi Kayu Tropis 5(1): 1-6.
Picchio R, Neri F, Maesano M, Savelli S, Sirna A, Blasi S, Baldini, Marchi E. 2011. Growth effects of thinning damage in a corsican pine (Pinus laricio Poiret) stand in Central Italy. Forest Ecology and Management 262 (2011): 237-243.
Pikk J, Kask R, Peterson P. 2006. The wood quality of fertilized scots pine (Pinus sylvestris L.) stands on vaccinium vitis-idaea and cladonia site type. Metsanduslikud Uurimused 44: 9-19.
Pinkard EA, Neilsen WA. 2003. Crown and stand characteristics of Eucalyptus nitens in response to initial spacing: Implications of thinning. Journal of Forest Ecology and Management 172 (2003): 215-227.
Pliura A, Yu Q, Zhang SY, Mackay J, Pierre P, Bousquet J. 2005. Variation in wood density and shrinkage and their relationship to growth young poplar hybrids crosses. Forest Sci J 51: 472-482.
Raiskila S, Pulkkinen M, Laakso T, Fagerstedt K, Löija M, Mahlberg R, Paajanen L, Ritschkoff AC, Saranpää P. 2007. FTIR spectroscopic prediction of klason and acid soluble lignin variation in norway spruce cutting clones. Silva Fennica 41(2): 351-371.
Rokeya UK, Hossain MA, Ali R, Paul SP. 2010. Physical and mechanical properties of (Acacia auriculiformis x A. mangium) hybrid acacia. Journal of Bangladesh Academy of Sciences 34 (2): 181-187.
21 Sadegh AN, Kiaei M, Samariha A. 2012. Experimental characterization of shrinkage and density of Tamarix aphylla wood. Cellulose Chem. Technol 46 (5-6): 369-373.
Siarudin, Marsoem. 2007. Karakteristik dan variasi sifat fisik kayu mangium pada beberapa jarak tanam dan kedudukan aksial-radial. Jurnal Pemuliaan Tanaman Hutan 1(1): 1-11.
Sukendro A, Sugiarto E. 2012. Respon pertumbuhan anakan Shorea leprosula Miq, Shorea mecistopteryx Ridley, Shorea ovalis (Korth) Blume dan Shorea selanica (DC) Blume terhadap tingkat intensitas cahaya matahari. Jurnal Silvikultur Tropika 03 (01): 22-27.
Taylor AM, Barbara, Gartner, Morrel JJ. 2003. Co-incident variations in growth rate and heartwood extractive concentration in douglas-fir. Journal of Forest and Management 186 (2003): 257-260.
_________, Gartner BL, Morrell JJ. 2006. Western redcedar extractives: Is ther a role for the silviculturist? Forest Products Journal 56 (3): 58-63.
Uner B, Oyar O, Var AA, Altnta OL. 2009. Effect of thinning on density of Pinus nigra tree using X-ray computed tomography. Journal of Environmental Biology 30 (3) 359-362.
Wang HL, Wang SY.1999. Effect of moisture content and specific gravity on static bending properties and hardness of six wood species. Journal of Wood Science 45 (2) 127-133.
Wardani L, Bahtiar ET, Sulastiningsih IM, Darwis A, Karlinasari L, Nugroho N, Surjokusumo S. 2011. Kekuatan tekan dan poisson kayu pangsor ( Ficus callosa Willd) dan kecapi (Sandoricum kucape Merr). Jurnal Ilmu dan Teknologi Hasil Hutan 4(1): 1-7.
Zhang SY, Chauret G, Swift E, Duchesne I. 2006. Effects of precommercial thinning on tree growth and lumber quality in a jack pine stand in New Brunswick, Canada. Can. J. For. Res. 36 : 945-952.
Zziwa A, Kaboggoza JRS, Mwakali JA, Banana AY, Kyeyune RK. 2006. Physical and mechanical properties of some less utilised tropical timber tree species growing in Uganda. Uganda Journal of Agriculturel Science 12(1): 29-37.
22