Decay Resistance and Extractive Content of Second-Growth Port Orford Cedar (<i>Chamaecyparis Lawsoniana</i>) Wood


  • Elijah Ajuong
  • Camille Freitag
  • Jeffrey J. Morrell


Port Orford cedar, decay resistance, <i>Postia placenta</i>, <i>Gloeophyllum trabeum</i>


Port Orford cedar (Chamaecyparis lawsoniana) has a reputation for being resistant to fungal attack, but much of the work to support this premise used older growth material (80-100 yr old). Given the tendency for the heartwood from the second growth of some species to be less durable, we evaluated the decay resistance of Port Orford cedar heartwood from 12 trees in laboratory soil block tests using Postia placenta and Gloeophyllum trabeum as the test fungi. Weight losses ranged from as little as 1.1 to more than 60% with most blocks experiencing weight losses between 11 and 24%. Heartwood was resistant to attack by G. trabeum but proved to be very susceptible to P. placenta and was only moderately resistant to this species. These results suggest that the durability rating of second-growth Port Orford cedar merits a re-evaluation.


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Research Contributions