Re: decay meters
jdunster@bigfoot.com
Mon, 22 Jun 1998 16:05:06 -0500
Torrey mentions the plugs required for removal from the Arborsonic, with apparent horror. In fact I think it is the least invasive tool since all we do it cut out a small disc of cambium down to but not into the xylem. Gluing the plugs back in is purely cosmetic in most cases, although I have heard of instances where a graft has taken place successfully. Based on trees I have revisited a year or more afterwards, it is clear that this "wound" develops new callus tissue readily. Contrast that to an increment core or the resistograph, both of which create a deep seated wound right into the heart of the tree. As for use and accuracy, I have one of each and am building up my own knowledge using empirical findings. So far both machines have provided very good and consistent results. But, like all such toys, they can be widely misinterpreted and easily abused in the wrong hands. They are an adjunct, an extra tool,in the kit bag, but by no means the only one at our disposal.
However, I do not think dismissing them is fair or reasonable. They are expensive and yes, they are not an ultimate answer for all ills that might plague a tree. Apart from any other consideration, all such readings, including an incrwement core, tell you something about the tree in that one plane at that one point. The tree has plenty of other options to confound readings taken at that one place and point in time. Visual tree assessment is still a basic requirement - all other readings refine the basic understanding.
Julian Dunster
Bowen Island, BC.