Posted: Thu Jan 24, 2013 9:37 pm
by edfrank
Michael,

Definitely the lower values in these trees reflect a flaring base rather than the general shape of the tree. The value is only useful if girth is taken above the inflated base, or the resulting cylinder will be too large, and the occupation percentage will be too low. It is an idea I proposed several years ago when first looking at general shape of the trees based up the tsuga search data Will had collected. It was never pursued aside from a few calculations from miscellaneous data. I think it is a worthwhile idea as it can be used to roughly estimate the volume of a tree with limited data. There is still a range of possible volumes. I think the 40% or so of the cylinder volume is a good first approximation for old growth big trees. It is applicable to trees that essentially have a single trunk that extends from the base to the top. I don't think it will be useful for broad crowned deciduous trees whose trunks split into numerous side branches as they approach the top.

Edward Frank