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

https://doi.org/10.22146/jik.8547

Sri Nugroho Marsoem(1*), Vendy Eko Prasetyo(2), Joko Sulistyo(3), Ganis Lukmandaru(4)

(1) Bagian Teknologi Hasil Hutan, Fakultas Kehutanan, Universitas Gadjah Mada
(2) Bagian Teknologi Hasil Hutan, Fakultas Kehutanan, Universitas Gadjah Mada
(3) Bagian Teknologi Hasil Hutan, Fakultas Kehutanan, Universitas Gadjah Mada
(4) Bagian Teknologi Hasil Hutan, Fakultas Kehutanan, Universitas Gadjah Mada
(*) Corresponding Author

Abstract


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, Gunungkidul


A study of teak wood quality from community forests in Gunungkidul II. Growth-stress measurement

Abstract

Trees 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.


Keywords


Tectona grandis; , growth-stressreleased strain; Gunungkidul; wood properties

Full Text:

PDF


References

  1. Almeiras T, Yoshida M, & Okuyama T. 2006. Strains inside xylem and inner bark of a stem submitted to a change in hydrostatic pressure. Trees 20, 460-467.
  2. Archer RR. 1986. Growth Stresses and Strains in Trees. Springer, Berlin.
  3. ASTM. 2002. ASTM D 2395–02. Standard test method for specific gravity of wood and wood-based materials. Annual book of ASTM standards. Volume 04.10-Wood. West Conshohocken, PA: American Society for Testing and Materials.
  4. BSN. 2010. Kayu Bundar Jenis Jati - Bagian 1. : Klasifikasi, persyaratan, dan penandaan. Standar Nasional Indonesia 7535.1:2010. Badan Standardisasi Nasional, Jakarta.
  5. Bhat KM, Priya PB, & Rugmini P. 2001. Characterisation of juvenile wood in teak. Wood Science and Technology 34, 517-532.
  6. Boyd JD. 1972. Tree growth stresses. V. Evidence of an origin in differentiation and lignification. Wood Science and Technology 6, 251-262.
  7. Cassens DL & Serrano JR. 2004. Growth stress in hardwood timber. Proceedings of the 14th Central Hardwood Forest Conference. March 16 – 19, 2004, Wooster, Ohio. pp. 106-115.
  8. Cown DJ & Ball R. 2001. Wood densitometry of ten Pinus radiata age at seven contrasting sites: in?uence of tree age, site, and genotype. New Zealand Journal of Forestry Science 31(1), 88-100.
  9. Fournier M, Bordonne PA, Guitard D, & Okuyama T. 1990. Growth stress patterns in tree stems : A model assuming evolution with the tree age of maturation strains. Wood Science and Technology 24, 131-142.
  10. Jacobs MR. 1945. The growth stresses of woody stems. Comm For Bur Aust Bull 24, 36.
  11. Johansson M & Ormarsson S. 2009. Influence of growth stresses and material properties on distortion of sawn timber - numerical investigation. Annals of Forest Science 66, 604.
  12. Kubler H. 1987. Growth stresses in trees and related wood properties. For. Abstr. 48, 131-189.
  13. Marsoem SN. 2013. Studi mutu kayu jati di hutan rakyat Gunung Kidul. I. Pengukuran laju pertumbuhan. Jurnal Ilmu Kehutanan 7, 108-122.
  14. Munch E. 1938. Statics and dynamics of the cell wall’s spiral structure, especially in compression wood and tension wood. Flora 32, 357-424.
  15. Okuyama T, Kanagawa Y, & Hattori Y. 1987. Reduction of residual stresses in logs by direct heating method. Mokuzai Gakkaishi 33, 837-843.
  16. Okuyama T & Sasaki Y. 1979. Crooking during lumbering due to residual stresses in the tree. Mokuzai Gakkaishi 25, 681-687.
  17. Okuyama T, Yoshida M, & Yamamoto H. 1995. An estimation of the turgor pressure change as one of the factors of growth stress generation in cell walls. Diurnal change of tangential strain of inner bark. Mokuzai Gakkaishi 41, 1070-1078.
  18. Okuyama T, Doldán J, Yamamoto H, & Ona T. 2004. Heart splitting at crosscutting of eucalypt logs. Journal of Wood Science 50, 1-6.
  19. Ormarsson S, Dahlblom O, & Johansson M. 2009. Finite element study of growth stress formation in wood and related distortion of sawn timber. Wood Science and Technology 43, 387-403.
  20. Saurat J & Gueneau P. 1976. Growth stresses in Beech. Wood Science and Technology 10, 111-123.
  21. Solorzano S, Moya R, & Murillo O. 2012. Early prediction of basic density, shrinking, presence of growth stress, and dynamic elastic modulus based on the morphological tree parameters of Tectona grandis. Journal of Wood Science 58, 290-299.
  22. Valencia J, Harwood C, Washusen R, Morrow A, Wood M, & Volker P. 2011. Longitudinal growth strain as a log and wood quality predictor for plantation-grown Eucalyptus nitens sawlogs. Wood Science and Technology 45, 15-34.
  23. Wahyudi I, Okuyama T, Hadi YS, Yamamoto H, Yoshida M, & Watanabe H. 1999. Growth stresses and strains in Acacia mangium. Forest Product Journal 49, 77-81.
  24. Wahyudi I, Okuyama T, Hadi YS, Yamamoto H, Yoshida M, & Watanabe H. 2000. Relationship between growth rate and growth stresses in Paraserianthes falcataria grown in Indonesia. Journal of Tropical Forest Science 6(1), 95-105.
  25. Wahyudi I, Okuyama T, Hadi YS, Yamamoto H, Watanabe H, & Yoshida M. 2001. Relationship between released strain and growth rate in 39 year-old Tectona grandis planted in Indonesia. Holzforschung 55, 63-66.
  26. Washusen R, Ilic J, & Waugh G. 2003. The relationship between longitudinal growth strain, tree form and tension wood at the stem periphery of ten- to eleven-year-old Eucalyptus globulus Labill. Holzforschung 57, 308-316.
  27. Watanabe K, Yamashita K, & Noshiro S. 2012. Non-destructive evaluation of surface longitudinal growth strain on Sugi (Cryptomeria japonica) green logs using near-infrared spectroscopy. Journal of Wood Science 58, 267-272.
  28. Yoshida M, Yamamoto O, Tamai Y, Sano Y, Terazawa M, & Okuyama T. 1999. Investigation of change in tangential strain on the inner bark of the stem and root of Betula platyphylla var. japonica and Acer mono during sap season. Journal of Wood Science 45, 361-367.
  29. Yoshida M & Okuyama T. 2002. Techniques for measuring growth stress on the xylem surface using strain and dial gauges. Holzforschung 56, 461-467.



DOI: https://doi.org/10.22146/jik.8547

Article Metrics

Abstract views : 3328 | views : 5361

Refbacks

  • There are currently no refbacks.


Bookmark and Share


Copyright (c) 2014 Jurnal Ilmu Kehutanan

License URL: https://creativecommons.org/licenses/by-nc-sa/4.0/

© Editorial Board Jurnal Ilmu Kehutanan
Faculty of Forestry, Universitas Gadjah Mada
Building D 2nd floor
Jl. Agro No 1, Bulaksumur, Sleman 55281
Phone. +62-274-512102, +62-274-550541, +62-274-6491420
Fax. +62-274-550541 E-mail : jik@ugm.ac.id
former website : jurnal.ugm.ac.id/jikfkt/
new website : jurnal.ugm.ac.id/v3/jik/

 

Indexed by:

 

Jurnal Ilmu Kehutanan is under the license of Creative Commons Attribution-ShareAlike 4.0 International