Compression Wood in Western Hemlock <i>Tsuga Heterophylla</i> (RAF.) Sarg.


  • Somkid Siripatanadilok
  • Lawrence Leney


Compression wood, opposite wood, fibril angle, microfibril angle, tracheid length, lignin content, across-ring variation, around-stem variation, wood anatomy, <i>Tsuga heterophylla</i>


The anatomical structure of the wood of western hemlock was studied for trees with different lean angles. Fibril angle, tracheid length, and lignin content are reported here for different positions across the outermost growth ring and positions around the stem for each lean angle. No significant difference in fibril angle or tracheid length was formed across the ring in the control tree of zero lean angle. Differences were found for all characteristics measured for positions around the stem of leaning trees. Compression wood had larger fibril angle, shorter tracheid length, and higher lignin content than either side wood or the control tree. Opposite wood was very variable for different lean angles. For compression wood, the fibril angle and lignin content increased for lean angles from 0 to 20°, then remained relatively constant for larger lean angles. Tracheid length showed a similar but inverse change with lean angle.


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