| [College of ACES] | [University of Illinois] | [Illinois CES] |
hbell@cdsnet.net
Mon, 1 Dec 1997 10:48:59 -0600
This Adjusted Trunk Appraisal formula is way off. While I'm waiting for the "Guide for Plant Appraisal," does anyone know what's wrong with this formula?: ATA = -.335d + 69.3d squared - 1087.
____________________
I took the time to look over my previous post on this subject, and I apologize for my somewhat intemperate and seemingly dismissive pop-off on the issue. Every question is entitled to a reasonable and thoughtful answer if this forum is to have any meaning, so I'll spend a bit of extra time on my observations:
____________________
Any tree appraisal analysis, for any purpose, is rooted in the attitudes and circumstances of it's creator. When someone chooses their appraisal objective, they gather established opinions--or sometimes strike off on their own--and then select the mathematics from some big bucket of formulas and numeric or statistical constructs. Who they are, as authors or creators, is blended in with the context of where they live, in their sense of the intended audiences.
The value of a tree must be staggering to a child looking at a huge live oak for the first time in its magnificent spread and strength. For a number of moments, it must be the most beautiful thing they have ever seen. So, let's set that as one end of the value of trees.
At the other end, let's take my across-the-way neighbor who thinks that trees aren't worth the gas in the tank of a chain saw--and has set out to enforce that view while I am forced to watch.
At one end, the awe of a child, and at the other, the contempt of a man who probably thinks he can grow pink flamingos out of those little plastic packing peanuts if he watered them with strawberry soda.
Now, somewhere between these two edges, in a descending scale, comes the arboretums--arborists--enlightened cities--teachers--ordinary people--bureaucrats--judges and lawyers--insurance companies--and folks like Mr. T.
All of us personally, probably fall somewhere in that range of reverence to contempt, so when we start on an appraisal concept, whether or not we mean to, we will probably carry that baggage along into our start-up reasoning. Next, obviously by necessity, we would be responsive to the real-world audiences for whom we are constructing this appraisal concept.
So, to me, there are at least two expectable predispositions hidden in any theory of appraisal, first the author, and second, the expectations of the audience. A bean counter working for an insurance is not likely to either create or to accept any appraisal scale positioning that affords trees any value other than one near the contempt (euphemistically called 'cost sensitive') end of the scale.
In fairness, there is also the same prejudice in setting up appraisal parameters by someone who loves trees on behalf of an audience that welcomes and encourages the tall creatures.
Both sides then bring in mathematics--sterile abstractions that live in their own universe that couldn't care less about humanity's thoughts and feelings--and both sides try to superimpose and force fit those slippery little numbers into each appraisal concept that best supports the original predispositions of each of the authors.
It's easy to reach into that big bag of numbers and formulas, look them over and discard the ones you don't want, then choosing the ones that better meet your original scaling and attitudes. Slide them around, change em, distort em, then hide em because it's unlikely anyone that any really would look at how this particular sausage is made. The recipients are usually only concerned about what comes out of the hopper at their end and whether it fits their needs.
So what difference does it make in the formula: ATA = -.335d + 69.3d squared - 1087, if it's -.34>9<d + 69.3d squared - 1087, or +.335d + 69.3d squared >+< 1087, or whatever?
In science, formulas approximate the laws of physics, and chemistry, and the universe. (They actually do it rather poorly and incompletely, but we still do love them.) But how will these little sterile adjectives and adverbs help us make sense of the admittedly human emotional values we assign to trees?
It's quite clear where I sit in the spectrum, and I hope with this, the beginnings of what I think about the always futile attempts to mechanize or quantify the value of trees. Those poised out there to lecture me or teach me on the TRUE method, shouldn't bother. I'm not predisposed to spend much time on how many angels can dance on the head of a pin or other sophomoric diversions that keep us from seeing the trees. One of these days, I get around to publishing my larger explanation of what I think I see, but right now, this is just a hopefully better filled-in apology for my being short and non-illuminating to an honest question.
Drop any number anywhere in that equation, set decimal points a'dancing, and how does any of that move us toward a better understanding of a tree's value?
Give that new formula on a piece of paper to our child staring up into the lush green canopy of that oak and I doubt he will give it a glance before he lets it fall to the ground. Only those of us taught that scribbles on a piece of paper have some special meaning of their own will look down to see what it says.
What a shame, not seeing the trees for the numbers.
Bob Wulkowicz