On Tuesday, May 06, 1997 Gordon J. Esplin wrote: >However, if the tree grows 16" in > 4 years than the growth rings must be about 2" apart and the wood must be of > little value for construction (but possibly okay for pulp). I'm not expert on Paulownia but I would like to dispel the "tree ring width as a measure of wood value" myth. The common misconception is that the "rings" are what make wood strong so therefore the more there are the stronger the wood. Another common misconception is that a 1" ring contains the same amount of fibre as a 1/8" ring, that the 1" ring is kind of "puffed up". Both these misconceptions have a little truth in them. Within a single species a tree that grows four times as fast will often be not quite as strong or dense, but nothing approaching only 1/4 the strength, more like 80%. This is because when trees grow faster they are actually putting on more wood than the slower growing tree. A species like Eucalyptus grandis, for example, can grow at a rate of 50+ m3/yr/ha and yet is a very dense hardwood. Another good example is the radiata pine grown in New Zealand. It grows to sawlog diameter in 30-35 years but it is very strong and makes beautiful furniture and fine construction timber. Patrick Moore, Greenspirit 4068 West 32nd Avenue Vancouver, BC, CANADA V6S 1Z6 e-mail pmoore@mail.bc.rogers.wave.ca 604-221-1990 ph. 604-221-1990 fax May the Forest be With You http://www.forest.org ----------
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