Studi Mutu Kayu Jati di Hutan Rakyat Gunungkidul I. Pengukuran Laju Pertumbuhan

Kabupaten Gunungkidul menyimpan potensi sebagai penyedia kayu jati sebagai bahan baku industri dari hutan rakyatnya. Penelitian ini bertujuan untuk mengetahui besarnya laju pertumbuhan dan riap pohon jati di hutan rakyat di Kabupaten Gunungkidul serta dihubungkan dengan faktor hujan. Tempat tumbuh yang diamati yaitu Panggang, Playen dan Nglipar. Pengamatan dilakukan selama 3 tahun, yaitu periode I (Oktober 2009-September 2010), periode II (Oktober 2010-September 2011), dan periode III (Oktober 2011-September 2012). Pengukuran diameter pohon dilakukan setiap akhir bulan pada 3 kelas diameter pohon, yaitu besar, menengah dan kecil, dengan ulangan 5 pohon tiap kelasnya. Hasil pengamatan menunjukkan rerata riap diameter tertinggi sebesar 2,21 ± 0,52 cm/tahun diamati di Panggang untuk kelas diameter besar sedangkan nilai terendah sebesar 0,33 ± 0,19 cm/tahun diamati di Nglipar yaitu untuk kelas diameter kecil. Kelas diameter besar memberikan nilai riap yang tertinggi. Pertumbuhan saat periode I hampir semua menunjukkan tertinggi pada semua tempat tumbuh dan kelas diameter. Secara umum, pengukuran riap bulanan menunjukkan adanya pertumbuhan minim dan minus antara Mei-September, puncak pertumbuhan antara Nopember-Februari. Korelasi Pearson antara riap dan curah/hari hujan untuk semua data menunjukkan korelasi sangat nyata antara riap bulanan dengan curah hujan (r = 0,24) atau hari hujan (r = 0,28). Korelasi data berdasarkan faktor tempat tumbuh memperoleh derajat korelasi tertinggi (r = 0,67) yang diamati di Playen khususnya di periode II. Rendahnya derajat korelasi secara umum mengindikasikan beberapa faktor lain perlu diperhitungkan untuk mengetahui kecenderungan pertumbuhan pohon hutan rakyat Gunungkidul.Katakunci: Tectona grandis, laju pertumbuhan, riap, Gunungkidul, curah hujan A Study of Teakwood Quality Grown in Community Forests in Gunungkidul, I. Measurement of Growth-RateAbstractGunungkidul regency has a potentiality to be a producer of teak wood as raw materials for industrial purposes. This study aimed to find out the growth-rate and increment levels of teak trees from community forests in Gunungkidul regency and to correlate it with the rainfall factor. Three observed sites were Panggang, Playen and Nglipar. The observation was conducted during 3 years, i.e. 1st period (October 2009-September 2010), 2nd period (October 2010-September 2011), and 3rd period (October 2011-September 2012). The measurements of diameter were performed on trees in 3 diameter classes (high, middle, small) every in the end of the month by 5 replications of each class. The results were the highest average of diameter increment were 2.21 + 0.52 cm/year observed in Panggang for high diameter class as the lowest level was 0.33 + 0.19 cm/year observed in Nglipar for small diameter class. High diameter class showed the highest increment values. Most of the growth-rate levels of 1st period were the highest in every sites and diameter classes. Generally, the measurement of monthly increment showed the minimum or minus growth between May and September, the highest increment peaks were measured during November – February. Pearson’s correlation for all the data between the rates of increment and rainfall (r = 0.24) or rainy day (r = 0.28) were significant. Data correlation on the basis of gowth-sites showed the highest degree which were observed in Playen, especially in the 2nd period. The weak correlation generally indicates the other factors should be considered to discover the trend of the growth of teak trees in the community forests of Gunungkidul regency

Utilization of Carbonized Wood from Tropical Fast-Growing Trees for Functional Materials

Pembangunan hutan tanaman dari jenis-jenis cepat tumbuh di kawasan tropis menimbulkan limbah biomassa kayu yang sebagian saat ini digunakan untuk kayu bakar dan sebagian lain digunakan untuk produksi arang dengan tujuan penggunaan yang terbatas. Pengembangan material-material fungsional untuk berbagai aplikasi teknik dengan memanfaatkan arang kayu dari jenis pohon cepat tumbuh harus mempertimbangkan struktur mikro dan struktur pori dalam arang kayu yang berhubungan dengan kondisi karbonisasi. Ulasan ini meliputi kemajuan penelitian-penelitian saat ini pada karbonisasi kayu dari pohon cepat tumbuh tropis, mekanisme perkembangan struktur mikro dan struktur pori dalam arang kayu selama karbonisasi, pemanfaatan yang tepat dari struktur mikro dan porositas dalam arang kayu untuk pengembangan material-material fungsional serta usaha dan peningkatan pengembangan material-material fungsional menggunakan arang kayu dari pohon cepat tumbuh tropis.Katakunci: arang kayu, material fungsional, pohon cepat tumbuh, karbonisasi Utilization of Carbonized Wood from Tropical Fast-Growing Trees for Functional MaterialsAbstractEstablishment of fast-growing tree species plantations in tropical areas generate wood biomass residue in which some of them are currently utilized for heating fuel and some others are used for charcoal production with limited purposes. The development of functional materials for engineering applications utilizing carbonized wood from fast-growing trees species have to consider the microstructure and pore structure in carbonized wood which has a relationship to the carbonization conditions. This review covers the current researches on progress in the carbonization of wood from tropical fast-growing trees, mechanism of the microstructure and pore structure development in carbonized wood during carbonization, proper utilizations of the microstructure and porosity in carbonized wood for the development of functional materials and efforts and enhancing the development of functional materials using carbonized wood from tropical fast-growing trees

A Review of the Factors Influencing Variations in the Heartwood Proportion for Solid Wood

Using 146 journals, 6 chapters, 4 reports, 2 books, and a proceeding, this research seeks to investigate the factors that influence variations in the proportion of heartwood. The data were collected through an online search in databases such as Scopus, Science Citation Index, Science Direct, Google Scholar, and ResearchGate with seven search queries, namely heartwood variability, heartwood proportion, tree age of heartwood, growth rate of heartwood, silvicultural treatment of heartwood, as well as genetic and environmental effects of heartwood. By eliminating papers that were out of topic or title, purpose and year of publication, 67 journal articles, 4 chapters, 3 reports, a book, and a proceeding were selected. The review results showed that the amount of heartwood was influenced by its position in the tree, tree variations, such as age, growth rate, and species/genera, as well as the growing conditions, including location and environmental factors. It is also affected by various silvicultural treatments, namely spacing, thinning, pruning, fertilization, and irrigation. These findings indicate that the amount of heartwood is more controlled by the diameter of the wood than the age. Furthermore, several studies reported that the growth rate of sapwood rings was significantly higher than the heartwood rings, which can reduce the quality of solid wood used for construction. Therefore, it is necessary to control the proportion of heartwood through genetics and environmental factors, especially genetics, which has more effects on the growth rate of tree diameter than environmental factors. Previous studies revealed that tree diameter has a weak or negative correlation with other wood properties, such as basic density, color, and wood stiffness, which are generally important in global markets. It is important for breeders to concentrate on using species with superior genetic variations as well, especially the highly demanded traits in further studies

Among-Clone Variations of Anatomical Characteristics and Wood Properties in Tectona Grandis Planted in Indonesia

Anatomical characteristics (vessel diameter [VD], fiber wall thickness [FWT], fiber diameter [FD], vessel element length [VEL], and fiber length [FL]) and wood properties (basic density [BD] and compressive strength parallel to grain [CS] in the green condition) were determined for 27 12-yr-old teak trees planted in Java Island, Indonesia. The mean values of VD, FWT, FD, VEL, FL, BD, and CS were 188 μm, 2.78 μm, 23.4 μm, 284 μm, 1.42 mm, 510 kg/m3, and 37.5 MPa, respectively. Significant differences in VEL, BD, and CS occurred among the nine clones. Moderate to high values of repeatability were obtained for FD, VEL, BD, and CS, indicating that these characteristics are genetically controlled. Radial variation of FL with respect to relative distance showed almost the same pattern for two different radial growth rates (faster and slower) at the same age, suggesting that xylem maturation in teak trees depends on cambial age rather than stem diameter

KEARIFAN LOKAL PENGGUNAAN KAYU GELAM DALAM TANAH RAWA GAMBUT DI KALIMANTAN TENGAH (Local Wisdom of Utilization of Gelam Wood on Peatswamp Land of Central Kalimantan)

ABSTRAKMasyarakat di daerah rawa gambut memerlukan kayu sebagai cerucuk atau tiang pancang rumah. Kayu Gelam (Maleleuca sp) ditemukan melimpah di hutan rawa gambut di Kalimantan. Kayu Gelam termasuk kelas awet 3 yang berarti hanya dapat dipergunakan di bila berhubungan dengan tanah selama 3 tahun. Kenyataan yang ada kayu Gelam sebagai cerucuk /tiang pancang rumah dalam tanah rawa tetap kuat lebih selama lebih dari 30 tahun. Pemanfaatan kayu ini mendukung untuk konservasi hutan rawa gambut. Tujuan dari penelitian ini adalah untuk melestarikan hutan di peatwamp melalui penghematan pemanfaatan kayu yaitu dengan mempelajari pengaruh lama penimbunan dan letak radial terhadap sifat fisika, mekanika dan kandungan silika kayu Gelam. Penelitian dilakukan pada kayu Gelam yang telah ditimbun dalam rawa gambut selama 10, 19, 31 dan 38 tahun. Sifat kayu yang dianalisis adalah sifat fisika mekanika mengikuti BS No 373. Uji silika dengan spektrometer. Analisis menggunakan rancangan acak lengkap dengan faktorial. Hasil menunjukkan bahwa lama penimbunan meningkatkan berat jenis kayu Gelam secara signifikan. Semakin lama penimbunan, semakin tinggi berat jenis (0,54-0,75). Persamaan yang diperoleh Y=0,449+0,063x1+0,01x2 (Y=BJ kering tanur, x1= lama penimbunan, x2= letak radial). Pengaruh lama penimbunan pada kekerasan sejalan dengan BJ. Kadar silika kayu Gelam meningkat dengan semakin lama penimbunan. Lama penimbunan (10-38 tahun) meningkatkan BJ kering tanur 28,13 %, kekerasan 12,83%; kandungan silika 1,25%. Penggunaan kayu Gelam merupakan kearifan lokal yang terbukti melestarikan lingkungan karena menghemat pemanfaatan kayu yang dinyatakan dengan kualitas kayu Gelam yang relatif tidak menurun dalam penimbunan.ABSTRACTLocal community on peatswamp area need woods as poles. Gelam (Maleleuca sp) wood is found abundantly in peatswamp forest area in Kalimantan. It is 3th durability class and expected to withstand up to three years of utilitation outdoor. However, gelam wood used for house poles in peatswamp could be still strong enough more than 30 years. Utilization this wood supports to conservation of peatswamp forest. The aim of this research is to study the effect of burying time and radial position to physical, mechanical properties and silica content of gelam The research was conducted by gelam wood which buried in peatswamp for several years namely 10, 19, 31 and 38 years. Wood properties that analyzed were physical and mechanical properties followed the British Standard No. 373. Silica testing by spectrometer. Analyze use factorial experimental of Completely Random Design. The result showed that wood specific gravity significantly increase with the lenght of burying time. The longer burying time, the higher wood specific gravity (0.54 to 0.75). Equation Y=0.449+0.063x1+0.01x2 (Y=oven dry SG, x1=burying time, x2=radial posision). The effect of burying time on hardness parallel with wood specific gravity. Burying time factor increase value of specific gravity 28.13 %, hardness 12.83%; silica content 1.25%. The use of gelam wood support to conserve the environment because it saves wood utilization expressed by gelam wood quality relatively undegradation in burial

Studi Mutu Kayu Jati di Hutan Rakyat Gunungkidul II. Pengukuran Tegangan Pertumbuhan

Pohon dengan tegangan pertumbuhan yang tinggi dikhawatirkan akan mudah mengalami cacat seperti pecah, retak, dan pelengkungan. Penelitian ini bertujuan untuk mengetahui variasi nilai tegangan pertumbuhan pohon jati yang tumbuh di tiga tempat hutan rakyat Gunungkidul. Nilai pelepasan regangan juga dibahas dari hubungannya dengan kecepatan tumbuh dan berat jenis. Pelepasan regangan pada arah longitudinal dan tangensial ditentukan melalui metode strain-gauge. Nilai pelepasan regangan di permukaan batang berkisar antara -130,5 sampai -999,5 µå sedangkan nilai pelepasan regangan tangensial antara -103 to 1411,5 µå. Beberapa nilai pelepasan regangan longitudinal yang cukup tinggi mengindikasikan adanya kayu tarik. Selanjutnya, variasi dalam pohon untuk tegangan pertumbuhan menunjukkan tidak ada kecenderungan tertentu. Perbedaan nyata diamati dimana sampel dari Nglipar memberikan nilai paling tinggi (-628,25 + -223,73 µå). Meskipun demikian, tidak ada hubungan nyata yang diukur antara nilai pelepasan regangan dihubungkan dengan laju pertumbuhan dan berat jenis. Penyebaran nilai tegangan sisa internal dalam arah radial bervariasi diantara pohon satu dengan lainnya dimana beberapa sampel menunjukkan adanya perbedaan nilai pelepasan regangan yang drastis. Untuk itu, perlu dilakukan usaha untuk mengurangi perbedaan yang mencolok di nilai pelepasan regangan dari pusat ke permukaan batang untuk mencegah cacat yang berkaitan dengan tegangan pertumbuhan.Katakunci: Tectona grandis, tegangan pertumbuhan, pelepasan regangan, sifat kayu, GunungkidulA study of teak wood quality from community forests in Gunungkidul II. Growth-stress measurementAbstractTrees containing large growth stresses, leads to significant losses due to split, checked and also warped. The variation of growth-stress in teak trees grown in the three community forest sites of Gunungkidul regency was observed. The released strain levels were also discussed in relation to the growth-rate and specific gravity. The strains released in the longitudinal and tangential directions were measured by the strain-gauge method. The values of longitudinal released strain at the periphery of the stem were ranged from -130.5 to -999.5 µå whereas tangential released strain were from -103 to 1411.5 µå. Some high values of longitudinal released strain indicated the presence of tension wood. Further, intra-tree variation of growth stress showed no particular tendencies among the samples. There were significant differences in the longitudinal strain as samples from Nglipar site showed the highest amounts (-628.25 + -223.73 µå). However, no significant correlation was found between the values of released strains with the growth-rate and specific gravity. The radial distributions of internal residual-stress were varied among the individuals which some trees exhibited steeper released strain gradients. Thus, it is important to reduce the gradient from pith to periphery of released-strain patterns to prevent the defect related to the growth stresses

Studi Mutu Kayu Jati di Hutan Rakyat Gunungkidul III. Sifat Fisika Kayu

Penelitian ini bertujuan untuk mengetahui variasi sifat fisika kayu dari pohon jati yang tumbuh di 3 tempat berbeda (Panggang, Playen, Nglipar) hutan rakyat di kabupaten Gunungkidul. Parameter yang diukur adalah kadar air segar (KAS), kerapatan dasar (KD), dan penyusutan linier maupun volumetrik. Sebanyak 3 pohon di tiap lokasi ditebang kemudian tiap pohon dibagi menjadi 3 potongan di posisi aksial yaitu pangkal, tengah, dan ujung. Tiap potongan tersebut kemudian dibagi 3 dalam posisi radial yaitu dekat hati, tengah, dan dekat kulit. Kisaran nilai KD dan KAS adalah 504-672 kg/cm3 dan 47-125%, secara berturutan. Hasil analisis keragaman menunjukkan sampel Playen bagian ujung cenderung memberikan nilai rerata KD lebih tinggi demikian juga bagian dekat kulit pada arah radial. Sampel Nglipar memberikan nilai kisaran KAS paling rendah (47-70%) sedangkan pada posisi radial nilai rerata tertinggi diamati di dekat hati (100,51%). Kisaran nilai penyusutan longitudinal, radial, dan tangensial adalah 0,39-0,88%; 2,75-3,93%; dan 4,30-6,68%, secara berturutan. Hasil analisis keragaman menunjukkan pengaruh faktor tempat tumbuh dimana sampel Nglipar memberikan nilai penyusutan longitudinal dan tangensial terendah. Nilai penyusutan total dalam kisaran 5,26-15,07%, sedangkan perbandingan penyusutan tangensial dan radial (rasio T/R) antara 1,38-2,13. Secara umum, kerapatan dasar yang diukur mempunyai nilai yang tidak jauh dengan nilai dari beberapa penelitian terhadap jati konvensional serta lebih tinggi dari beberapa jati unggul dari kultur jaringan pohon umur muda. Perlu diperhatikan adalah tingginya penyusutan dan ketidakstabilan dimensi yang diukur di beberapa sampel dalam eksperimen ini.Kata kunci: Tectona grandis, sifat fisika, kerapatan dasar, hutan rakyat, GunungkidulA study of teak wood quality from community forests in Gunungkidul III. Physical propertiesAbstractThe objective of this work is to explore the variation of physical properties of wood from teak trees grown in 3 different sites (Panggang, Playen, Nglipar) from community forests of Gunungkidul Regency. The measured parameters were green moisture content (GMC), basic density (BD), and linear as well as volumetric shrinkage. The three trees were collected at each site then were divided into three axial parts i.e. base, center, and top of the trees. Further, each axial part was divided into 3 radial positions i.e. near pith, middle, and near bark. The range of BD and GMC values were 504-672 kg/cm3 and 47-125%, consecutively. The result of analysis of variance showed that samples of Playen at the top parts tended to give higher average values of all physical properties measured as well as the samples at near bark of radial position. Samples from Nglipar exhibited the lowest range of GMC values (47-70%) whereas the highest values in the radial direction were observed in the near pith samples (100.51%). The range values of longitudinal, radial and tangential shrinkage were 0.39-0.88%; 2.75-3.93%; and 4.30-6.68%, respectively. By analysis of variance, site factor significantly affected of which samples of Nglipar showed the lowest levels of longitudinal and tangential shrinkage. The total shrinkage values were 5.26-15.07% as the T/R ratio were 1.38-2.13. In general, the BD levels of teak from Gunungkidul were comparable to those reported for conventional for teaks plantation and higher than those of young tissues cultural teaks. However, attention should be taken as the high magnitude of shrinkage as well as dimensional stability showed by several samples in this experiment.

Studi Mutu Kayu Jati di Hutan Rakyat Gunungkidul IV. Sifat Mekanika Kayu

Sifat mekanika dari kayu gergajian adalah persyaratan terpenting dalam banyak penerapan khususnya untuk keperluan konstruksi. Paper ini merupakan lanjutan dari penelitian sifat fisika kayu di tiga tempat tumbuh (Panggang, Playen, Nglipar) hutan rakyat Kabupaten Gunungkidul. Pengujian sifat mekanika dilakukan mengacu pada British Standards 373:57. Hasil penelitian menunjukkan bahwa kayu yang diteliti termasuk dalam kelas kuat II-III. Dari perhitungan analisis varian, tempat tumbuh berpengaruh nyata pada modulus patah (MoR) keteguhan lengkung statik, keteguhan tekan tegak lurus serat maksimum, keteguhan geser, dan kekerasan. Secara keseluruhan, kecuali untuk nilai MoR, sampel kayu dari Nglipar memberikan nilai kekuatan yang lebih tinggi. Pengaruh arah aksial dan radial pohon secara umum tidak begitu terlihat pada semua parameter kekuatan kecuali di keteguhan belah. Meskipun berkorelasi secara linier, hanya korelasi moderat yang diamati dari hubungan sifat mekanika (MoR/keteguhan geser) dan kerapatan dasar. Tidak ada korelasi nyata antara kerapatan dasar dan modulus elastisitas keteguhan lengkung statik serta antara kerapatan dasar dan keteguhan tekan sejajar serat maksimum.Kata kunci: Tectona grandis, sifat mekanika, kerapatan dasar, hutan rakyat, Gunungkidul. A study of teak wood quality from community forests in Gunungkidul  IV. Mechanical PropertiesAbstractMechanical properties of sawn timber are the most important characteristics in many applications, particularly for structural timber. The previous paper in this series reported on the physical properties of teak trees at different sites (Panggang, Playen, Nglipar) from community forests in Gunungkidul regency. In this study, the mechanical properties were evaluated according to British Standards 373:57. The results showed that the timber were classified in the II-III of strength class. By analysis of variance, site factor affected the values of modulus of rupture (MoR) in statical bending strength, maximum compression perpendicular to grain strength, shear strength and hardness. In general, except for MoR, the wood samples from Nglipar gave higher strength levels. Except for cleavage strength, the effects of the axial and radial position of the tree on mechanical properties were mostly negligible. Although linearly related, only modest correlations were observed between the mechanical parameters (MoR/shear strength) and basic density. No significant correlation was found between the values of basic density and modulus of elasticity of static bending strength as well as between basic density and the strength of maximum compression parallel to grain

LOCAL WISDOM IN UTILIZING PEAT SWAMP SOIL AND WATER TO IMPROVE QUALITY OF GELAM WOOD

Local wisdom in utilizing swamp soil and water to improve the quality of gelam wood in Central Kalimantan becomes an interesting phenomenon. Improving the quality of wood can economize on the use of wood, which in turn preserves the forests in peat swamp lands. Gelam (Melaleuca sp.) woods that are mostly found in peat swamp forests can be used as piles/stakes in swamp soil, and they are durable for decades. The general objective of this study was to provide a scientific explanation of the effect of peat swamp soil and water on improving the quality of gelam wood either in barked and barkless conditions. This study was conducted by taking gelam trees that grew in Central Kalimantan. It was carried out for 18 months, and investigated the barked/barkless woods, media (swamp water, freshwater, peat swamp soil, and sandy soil) and 3 lengths of burying times. Wood properties analyzed were physical and mechanical properties. The standard of physical-mechanical property tests referred to British Standard 373. The results showed that the interaction between bark factor (A) and media (B) affected specific gravity. Barked wood produced the highest spesific gravity in swamp water medium. Water media (swamp and fresh water) improved the wood’s specific gravity more than soil media (swamp and sandy soil). The highest values of hardness, stress on Proportional Limit, and Modulus of Elasticity were in the medium of swamp soil. The improvement of the quality of gelam woods, which were either buried or used as stakes/piles, was allegedly resulted from the swamp water infiltrating into gelam woods that thereby increased the specific gravity