# Tree height/dbh correlation chart?



## Gopher (Sep 25, 2002)

Good evening boys and girls. Say, I have been trying deligently to assist with the specifications for ROW clearing for electrical co-ops, and we are advancing from point A to Point C via point B. Anyway, I was wondering if there is such a thing as a rough guide for trre height/dbh by species?

I realize there are many factors to consider, and I am working with them on growth rates and species, but like I said, we aren't going to get to point C overnight!

I am just trying to gather as much information as possible to support ecenomical trimming or ecenomical removal based on proximity to clearance zones for different power lines (single phase, three phase, etc.

Thank you.

Gopher


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## Nickrosis (Sep 26, 2002)

Do you want to know what the relationship is between DBH and height for certain tree species? How would that relate to pruning?

I guess I'm unclear as to what you're asking. You could explain it when I see you on Monday. 

Nickrosis


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## TREETX (Sep 26, 2002)

Invest in a Sunnto clinometer. A cool little toy that will give you height.

I suppose you are aiming to make a computer model, etc??


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## Stumper (Sep 26, 2002)

In some areas with some species there is a recognizable correllation dbh/height. In the big picture though the variables are so great that I suspect that publishing such info might create more problems than it helps to solve.


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## Gopher (Sep 26, 2002)

Yes, a Suunto Clinometer I should get, and yes, I would like to come up with some sort of computer model that could help speed up the decisions in electric-based right-of-way clearing.

Some of the easements we are dealing with are different, and the width can differ depending on the type of transmission lines. It is my intention to make it easier for non-tree people to understand the economics as to why a tree will stay, and why it should not based on size (both dbh and height, tree growth rates and shape).

Good, I always am looking for an excuse to buy more toys! I haven't used a clinometer since college days. For the little I need it, I use the dbh tape and Biltmore stick.

I could use some help as to how I would go about starting a computer model with information I would be compiling. 

Thank you for the thoughts. I know I may seem vague and confusing on this, but that is because I am trying toput a square peg (ROW clearing) into a round hole (tree characteristics).

See you Monday, Nick.

Gopher


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## hillbilly (Sep 26, 2002)

Hi Gopher,
I'm involved in a project at the university.
The project is to (computer) model trees, tree growth and the
effects of pruning. The project is scheduled to end in januari/februari 2003. The outcome is, besides an extensive report, a computer program. The program could be used
to try different pruning techniques and see the resulting tree
a arbitrary number of years later.
If the project really gets this far remains to see, trees are
very complex and there are many factors affecting its growth.
If the program turns out well, I will gladly share it with
other tree entusiasts.

If I understand you correctly, you want to know if there is 
a (simple) relationship between tree height and diameter of trunk, right ?
In one of my books they have measured 576 american trees
and produced a graph, height as a function of diameter.
The relationship is not linear.
If you want, I might be able to scan the graph and post it.


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## geofore (Sep 26, 2002)

*chart*

This sounds as bad as the research done to find out if it was posible to grow strait and tall walnut trees. DBH to Hieght is more a relationship is it planted in full sunlight or in the shade of other trees. At best you could say that in full sunlight the trees are going to grow shorter and wider and in an area of the shaded by other trees the trees are going to grow taller reaching for sunlight and skinner for the lack of full sunlight. What the tree will do has more to do with where you plant it and what kind of tree it is.


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## hillbilly (Sep 26, 2002)

Of course you could find a function which maps trunk diameters
to tree heights in general, but you will get an outrageous error marginal, so I doubt it would be very useful.
The chart pretty much shows this, although height and
diameter increase with each other, the spread of the
two dimensions is great.
The compter model I work on does not take this "relationship"
into account, since it's pretty useless.


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## Gopher (Sep 26, 2002)

Thank you guys. This is what I wanted. I agree that there isn't a good correlation and I wanted some supporting comments to back me up when I revisit the Co-op CEO soon. 

I have begun to educate him, and he has come a long way, but every once in a while, he demands something that just isn't feasible.

Gopher.

P.S. Hillbilly, I still would be interested in the study; it may be useful in some way for general purposes.


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## hillbilly (Sep 26, 2002)

*tree height VS trunk diameter*

Here is the chart I was refering to in the earlier post.
It's on page 296 of the book "Tropical Trees and Forests", F.Hallé 1978.
It shows the height and trunk diameter of 576 "champion trees" of USA.

The one equation that I found for the realtion is this:
d = K * h^1.5

where d would be the diameter of the trunk,
K, a species dependant constant
and h the height of the tree
^ would mean "power"
I guees you could try and calculate the constant K
for a couple of trees of the same species to see
if the formula works.

I'll keep you posted on the progress of the tree model.

The image looks like something from the 19th century, it's because I took a shot with my camera, don't own a scanner.


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## John Paul Sanborn (Sep 26, 2002)

Dave, 

JOA had a paper on Tillia size estimations in europe http://joa.isa-arbor.com/request.asp?JournalID=1&ArticleID=53&Type=1

The conclusion is that for these specise we can preasonably predict the morphology longterm (100 years was the limit in this study). Short trem predictions of 15-20 years it becomes problematic.

If this is to be a laymans tool, then just making a chart of Large, Medium, Short would suffice.

Then what happens if i have a young 'Columnar' Norway maple in that position?


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## Gopher (Sep 26, 2002)

JPS: You then hire the arborist for even more time to make the decisions that need to be made in the field, which is what I am headed for. They now would like me to be there for them about 4 or 5 days amonth (at a very nice hourly rate). If we ned to up that by a day or two, I'm a happy camper!

What we have here is a very smart man trying to quantify and profile something that can't really be done to enable him to better predict volume and possible removals (hot customer spots) along the ROW..I don't blame him.

To adequately (and legally I might add) supply "uninterupted power", the easement area needs to be judicciously cleared. In most cases this is not enough, nor does the "lineal" measuring ever fit the right spot on the limb to make the proper cut. So, there is constant negotiating outside of the easement area to gain clearance and to the ccustomer's tree, make the proper cut back to a lateral.

In any event, we are gaining ground, and are trying to propagate decent trees adjacent to the ROW that can be managed in a more cost effective manor.

Think about it; which trees are our customers most usually most adament about keeping? The trees that are crowding the lines, the neighbors garage, the road, etc. The better we manage these trees that almost always need to be pruned, the more likely we will be to "touch" and care for all of their trees. 

Also, more often than not, since we have an easement to be on their property, I make a call. Often I may have to confront very irate people, but more often than not, I end up running a soil sample for them and making a recommendation on what they should plant further from the power lines that would thrive and be the appropriate size.

Thank you once again for the comments, and Hillbilly, I did run off a copy of the graph. 

Gopher


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## John Paul Sanborn (Sep 26, 2002)

If you did not check the JOA link, there are some graphs there too. one shows that there is around a 5 meter spread in hight at 20 years.

Here is an idea from a small comunity in Chicogoland. Give the people that get a tree removed a certificate to purchace a tree from a local nursery. Valid only for trees off utility approved list. $50-75 added onto the cost of the actual removal is chiken feed. The utility could probably work out a good discount on these trees too.

Let me know when you need a trusty sidekick


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