Journal of Korean Society of Forest Science (한국산림과학회지)

Korean Society of Forest Science (한국산림과학회)
권호 표지

Modeling Knot Properties for Mongolian Pine in Northeast China

  • Jia, Weiwei (School of Forestry, Northeast Forestry University) ;
  • Li, Fengri (School of Forestry, Northeast Forestry University) ;
  • Jiang, Lichun (School of Forestry, Northeast Forestry University)
  • Received : 2007.08.14
  • Accepted : 2008.06.27
  • Published : 2008.10.31
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Abstract

This study was performed in 14 unthinned Mongolian pine (Pinus sylvestris L. var. mongolica Litvin) plantations in northeast China. Data were collected on 70 sample trees of different canopy position with diameter at breast height (DBH) ranging from 6.9 cm to 34.5 cm. Diameter and length of knots per whorl below the living crown were studied by different vertical levels divided by relative knot height (RHK) in this paper. Models taking DBH and height to the crown base (HCB) as independent variables were developed to predict knot diameter (KD) in a sample whorl. According to the vertical distribution tendency and range of sound knot length (KLsound), KLsound was modeled as multiple linear function of DBH, KD and relative knot height (RHK). The loose knot length (KLloose) was described as a function of DBH, KD and height above the ground for knots (HK) in a mixed log-linear model. Results from this study can provide abundant knot information so as to describe the knot size and vertical distribution tendency of Mongolian pine plantation.

Keywords

References

  1. Lemieux, H., Zhang, S.Y. and Grondin, F. 2002. Improving Structural Lumber Quality in a Sample of Picea mariana Logs Sawn According to the Knots. Wood and Fiber Science. 34: 266-275.
  2. Lemieux, H., Usenius, A. and Samson, M. 1997. A method for the characterization of knots in logs. Forest Products Journal. 47: 57-63.
  3. Li, F.R., Choi, J.K. and Kim, J.H. 2001. The development of growth and yield models for the natural broadleaved-Korean pine forests in northeast China. Journal of Korean Forestry Society 90(5): 650-662.
  4. Li, F.R. and Yun, J.H. 1996. Effective crown form of Changbai Larch (Larix olgensis H.) plantation in Chagbai Mountain. Journal of Korean Forestry Society. 85(4): 557-564.
  5. Littell, R.C., Milliken, G.A., Stroup, W.W. and Wolfinger, R.D. 1996. SAS System for Mixed Models. SAS Institute Inc., Cary, NC, 633pp.
  6. Maguire, D.A. and Han, D.W. 1987. A Stem dissection technique for dating branch mortality and reconstructing past crown recession. Forest Science. 33: 858-871.
  7. Makinen, H. 2002. Effect of stand density on the branch development of silver birch (Betula pendula Roth) in central Finland. Trees. 16: 346-353.
  8. Oja, J. 1997. A comparison between three different methods of measuring knot parameters in Picea abies (L.) Karst. Scandinavian Journal of Forest Research 12: 311-315.
  9. Samson, M. 1993. Method for assessing the effect of knots in the conversion of logs into structural lumber. Wood and Fiber Science. 25: 298-304.
  10. Wagner, F.G. and Taylor, F.W. 1975. Simulated sawing with a chipping headrig. Forest Products Journal. 25: 24-28.