We are in the beginning stages of evaluating a stand of blue gum, planted in 1877. In addition to checking for structural defects, we are planning to Resistograph all trees with evident or suspected decay, and a random sampling of the remainder, and also to do selected root crown examinations and transect trenches with an Air-Spade to evaluate relative number of decayed and sound roots. I would like to hear from others who have evaluated old stands of blue gum, regarding relative numbers of decayed and sound trees, and extent of decay. We know we have Laetiporus, Ganoderma and probably Armillaria. Trees are tall (to 220') and target of individual trees ranges from moderate to very high.

Reply to post by Richard Trout, on May 21, 2001 at 17:14:54:

Hi Richard,

I know nothing at all about gums. Your approach sounds very thorough. What would concern me is how you set action thresholds for the "stand." Depending on stand density and orientation to wind, the components of the stand may present quite different risks from individual trees. The literature is pretty clear on what may happen if you create "edge" trees. If you start thinning or culling a stand becasue a, b or c tree has some risk factors do you create a new exposure and higher risk for trees x, y or z?

So do you take the most conservative approach and set action thresholds as if they were all individuals? Can you rely at all on the protective nature of the stand?

I don't really have any answers. It is always sensitive when you have to start dealing with significant trees that are "over mature."