Has anyone used the
Guide for Rating Condition and Location
Tree Appraisal Factors
by Minnesota Society of Arboriculture?
It is touted as a supplement to the 8th edition.
I realize the 9th edition is about to come out.
Will the 9th have this sort of info all ready?

Reply to post by Peter Torres, on December 16, 1999 at 21:59:38:

Peter,

I received the MN supplement as a courtesy from MN ISA, but have not used it in the field. It is a total of 60+ pp. on these two factors.

It adds considerable complexity to the analysis. In some respects this seems advantageous in that it forces the appraiser to consider and try to quantify many discrete elements. On the other hand it adds a significant amount of time (I would think) to the process and may impose arbitrary scaling on certain factors which may or may not influence perceived value.

A concern in MN for me would be if the supplement became a de facto standard, eliminating appraiser discretion and judgment... leaving the appraiser who chooses not to implement the supplement rigidly in all cases in a position of doing "sub-standard" work. The Jan. '99 Preface does allow such discretion. That's not of course an issue in other areas where it just becomes an informative tool if you think it's useful.

One technical thing that concerns me is the uniform relationship of tree value to site value in assigning the Site rating. In my opinion that should be the case IF the definition of value is the contribution of the tree to site value, but may not be meaningful if other definitions of value apply.

All in all, the supplement is the product of extensive committee work and provides, IMO, some quite useful tools. It's a worthwhile addition to your appraisal library. That said, appraiser judgment and understanding of VALUE remain very important. The supplement leans toward direct, technical measurement of physical characteristics in order to depreciate initial cost indications of value. The fact remains that VALUE is not a physical characteristic and is extrinsic to the tree.

Scott

The 12/98 Draft 9th Edition did not adopt this level of detail. I have not seen the more recent draft which I believe has gone to print.

Reply to post by Peter Torres, on December 16, 1999 at 21:59:38:

Peter,
The Minnesota Guide is just that! It is not a supplement or any part of the Guide For Plant Appraisal, 8th or 9th edition. Each ISA chapter is charged with coming up with their own regional guidelines, as described in both editions, and MN decided to go a little further. CTLA has reviewed their product in several stages of development and applaud their work and devotion. HOWEVER, as stated, it is not a part of THE GUIDE.
I agree with Scott that it has some merits, but it didn't sell me.
Very treely,
Lew

Reply to post by Peter Torres, on December 16, 1999 at 21:59:38:

Tossing in 2 cents worth-

I've reviewed the MN guidelines briefly. I don't think I'll be relying on them to a great extent, except perhaps as a checklist in the more detailed cases.

Years ago (I think 7th edition was in use then) I tried to do something similar, to come up with a set of standards that could be used anywhere, for any tree. The more I thought about it, the more complex the system became. Finally it was brought to my attention that it wasn't the intent of any appraisal system to work by quantifying everything to that level of detail. Trees are not widgets to be counted in a warehouse.

So I must agree with my esteemed colleagues, Lew and Scott, and suggest that this be considered as only a guide in formulating your opinion of value, not an absolute table that leads you to the "One True Value.”

Reply to post by lewbloch, on December 16, 1999 at 21:59:38:

Lew,

One of the big issues, I think, is the perception - among practitioners and consumers - that the Guide is a standard. THE way to estimate value. Maybe even the SOURCE of value.

Notice I said perception. You and I have had this conversation innumerous times. The Guide is a guide is a guide. CTLA can say it officially. It's always been in the preface in writing. But for too many people it's taken as a rigid standard.

Enter the regional guides. Notwithstanding your observation here, the MN-ISA C&L Guide says big and bold on its cover "A Supplement to the Guide for Plant Appraisal." Its preface indicates it is a companion to the Minnesota Supplement to the Guide for Plant Appraisal.

So, notwithstanding the caveat in the preface that appraiser discretion and judgment remain applicable, will it be perceived as a standard. Having provided the caveat, the preface goes on to state that it was the intent to establish a "standardized factor rating system," but that those appraisers who prefere to use a "personalized procedure" will find it helpful. It's almost as if the "pp" is being characterized as suspect.

This all brings me back to my same old song. We need to step back from complicated and standardized MEASUREMENT techniques and start with the very basics: the definition of value and of the appraisal problem. How can tree appraiser education start to do this Lew?

Reply to post by Russ Carlson, on December 16, 1999 at 21:59:38:

Quantification is the key concept in this discussion Russ. Quantification can be an important exercise in some appraisal models. It depends on what you're appraising and the definition of value. In timber appraisal a reasonably accurate quantification of the board feet of convertable fiber, of x quality and y species mix at z conversion costs is essential to the exercise.

But I think you're right. It's much less significant in landscape tree appraisal. In an effort to limit "subjectivity" and variance among appraisals, IMHO, there has been an ongoing effort to focus on precision in direct physical measurement. But value is not a physical characteristic and cannot be directly measured. Those physically measurable and quantifiable characteristics may or may not have an impact on value. Certainly a scrawny, scraggly tree in poor health with structural defects is likely to be less valuable than a well formed, healthy, structurally sound tree. But will two of those better trees vary in value because one has a different foliage texture or the other has a few aphids on it? The appraiser can only judge that by looking to the beneficiary and the effect on benefits. And yes that may get touchy-feely.

It may well be subjective vis-a-vis the subject of the appraisal. But that's the nature of value. If the appraiser keeps personal preference and bias out of the analysis and considers the nature of benefits and beneficiary as facts, then the asppraiser's analysis is objective... that is fact based. It may not be precise and should not be represented as precise. But appraisal is not a physical measurement exercise amenable to precision!

Removing appraiser judgement and ignoring the variability of benefits and beneficiaries as facts by implementing a standardized rating or scaling system or otherwise may not create a system that is objective, but merely arbitrary.

Reply to post by Scott, on December 17, 1999 at 17:37:14:

Right you are, Scott. We have had this conversation numerous times, AND we will probably have it even more times. I certaintly do not have the answer, other than to keep pushing out the word....the guide is only a guide!!!! Not a standard, not rules, not regulations. This forum is a help in getting out the word, as our other forums, appraisal workshops, and conferences
Although they have done some rally good work, I really don't think the MN. group is helping this effort.
On the other hand, you are to be commended for helping in the effort.
verytreely,
lew

Reply to post by lewbloch, on December 18, 1999 at 06:53:42:

Well thanks guys, I was worried. I just recieved their ad in the mail and wondered if I should send in the 37.50 to buy it. Then I wondered what I was going to do with it when the 8th edition was soon to be obsolete anyway. I think what they've done is good, but I don't want to have to change my evaluation spreadsheets too many times.

Reply to post by Debbie Ellis, on December 20, 1999 at 18:13:29:

Hi Debbie! Happy New Year and all that cool stuff. You made a wise decision. It is nice-to-know information, but should not change what you have been doing....Unless you get a case in Minnesota, of course.
Very treely,
Lew