Don Bertolette's Early Days in Forestry  

TOPIC: Pin oak tells the story
== 2 of 4 ==
Date: Tues, Jun 10 2008 12:00 am

Much of my time measuring trees in the woods was a function of my various employers, and until the late 1980s, in the western US where coniferous species are commercially dominant. In the year in year out life of a forester, much of the measuring of trees that is done, is done to predict volume for timber sales, so as to advertise it with an idea of the value of what was to be offered up for contract bidding. We got good at estimating volume and grade for fairly large stands. Commercial valuation didn't include tree height, but height to a predetermined commercial diameter limit (usually 4 to 6 inches). In our prime, I'd put us against your digital devices and win a bunch of beers estimating height at which 4 or 6 inches diameter was reached. Our work was randomly checked, and a lot of integrity was tied up in how accurate we were.

In my third year as a forest tech, still in school at Humboldt, I was crew chief on a Continuous Forest Inventory crew, on the Shasta-Trinity National Forest in Northwestern California. Our stands were overwhelmingly evergreen/coniferous, and simple to measure. We visited probably 75 plots over the summer we had in between classes, and carefully measured height, diameter at breast height, species, grade, community/habitat type, etc. We measured tree heights, from a two foot stump height which many times would be outside the 'butt swell'. Height was measured according to the tangent rule, although we didn't refer to it that way. Most of us operated by rules of the thumb. Rule 1, horizontal distance needed to exceed vertical distance. Rule 2, determine direction of lean (sweep) and measure at right angles to it. Rule 3, once Rule 1 was achieved, walk to a distance easy to convert in your head (200, 150 feet, 125 feet, 133 feet (or 132, if using topo clinometer)., Rule 4, measure top and bottom from same location. Acute angles were better than obtuse (topographically, measure from as much above as possible, as some coniferous species had rounded top that could cause error from not seeing actual top).

When possible, for efficiency, we'd often walk out equidistant from two or more trees if conditions permitted, which would allow us to measure two or more trees from same location. Not often, but not infrequently either, a series of trees would describe a rough line, or better, an arc that permitted 'two birds with one stone' opportunities.

When I went back East as a forest tech to Kentucky's Daniel Boone National Forest, it was more of the same, but deciduous trees posed special problems, as you well know. Even so, we had no real occasion on year in year out basis for measuring total tree height to the level of accuracy that ENTS achieves. We still measured to height of commercial top (when the final info you need is number of 4/8/16 foot logs, there are very distinct points of diminishing returns in careful measurement of top twigs). One tree in a hundred (not actually, but indeed a small fraction) where measured accurately to "top twig", as sample trees, but these weren't selected as champion trees, but random stand height trees, where being accurate to feet was adequate for the task. One further level of checks was having a limited sample of the "sample trees" taken to the mill for accuracy of volume measurements and tree grade (quality issues, clear, knot free, extent of rot, etc.).

I have tried to relate all this in a non-defensive tone, as I feel no need to rationalize my career as a forester. we did what was needed to be done for the time, and did it with all our hearts. Would I in retrospect, with omnicience, change anything? Oh, yeah, you bet...but that's another story.

TOPIC: Don Bertolette's early days in forestry

== 1 of 3 ==
Date: Tues, Jun 10 2008 12:36 pm


My friend, I certainly agree. You have no need to rationalize your forestry days. The techniques you used were sufficient for the job you were doing and your personal expertise in compensating for tree form in height measurements served you well. Knowing you well, I have absolutely no doubt of that. I am impressed with the methods you employed to minimize the crown offset error, and on a more general theme, I know plenty of foresters who can quickly estimate DBH and multiple log lengths with great accuracy. I stand in great respect of their abilities. The feathery tops of broad-crowned hardwoods was just never part of the game.

My presentation of statistics about the accuracy of the tangent method/rule is not in any way intended to point at field foresters who are competently doing their work. If some of my email communications have an underlying judgmental tone, I should apologize for not being more careful. I have to admit that the judgmental tone is unfortunately present and comes from my having locked horns over the years with a small, but vocal minority of folks who are incensed at being challenged by people outside their field, as though they held exclusive rights to the body of knowledge that involves measuring trees.

Innuendos aside, I usually find ways to temper my comments. At least I hope that is the case. However, I note that passions can run high on the subject. My buddy Will Blozan is inclined to engage in a full frontal assault. I think you've commented on Will's unbridled ferocity on an occasion or two. Just everybody be on guard. He who challenges brother Will on what Will darn well knows he's especially good at " 'ull git a can uv Georgia whoop-ass put on 'um."

In reflecting a little further on the subject, I think that both Will and I see ourselves, validly or invalidly, as carrying the banner for an area of knowledge that we see as getting bypassed or trivialized when trees are seen through an economic lens. Having just said that, though, I, in particular, have to be careful. In a recent telephone conversation, Lee Frelich observed that ecologists can get pretty sloppy with the max tree species heights when engaged in what stands for purely scientific research.


== 2 of 3 ==
Date: Tues, Jun 10 2008 5:46 pm

Re your phone conversation with Lee, it's been my impression that forest ecologists don't measure the height of anything accurately (well maybe a glass of beer...;>) just the presence or abundance, in general they're more qualitative than quantitative. Less of a physical science, more of an art.

== 3 of 3 ==
Date: Tues, Jun 10 2008 5:56 pm

Whoever has done me the kindness of changing topic heading, has missed my "early" days in forestry, when we surveyed with a steel "topo" tape that was designed to work in conjunction with a 'topo abney'; when we re-established our boundary lines using a mountain transit (much like the original surveyor whom we were 'mimicking'), and brushing line with a double bit ax and a 'Swede' (brand named Sandvik, it was a "safe" limbing blade)...chainsaws weren't then accepted in the field (big heavy brutes that we'd have fought having to carry).
But then that's another story...