What does dbh mean?

[fishhuntcutwood]

- but it is true.......

Well then, good for you Niko!!

 

[Gologit]

- but it is true.......

But how will we ever know for sure?

 

[Urbicide]

But how will we ever know for sure?

One picture is worth a thousand words. opcorn:

 

[Urbicide]

"Understanding Log Scales And Log Rules"

Here is a link for some good tree measuring info from the Agricultural Extension Service at the University of Tennessee.opcorn:

http://www.utextension.utk.edu/publications/pbfiles/Pb1650.pdf

 

[Fumbler]

If you're like me, you don't measure trees. You just look at them and know what the size is.
I'm usually within 3/10 of an inch on diameters and 3-5 feet on heights.

It is an appromate measurement of the trunk of a tree taken when a man is standing....shoulder height

DBH is measured at shoulder height only when you're a little shorter than average.
Breast height is 4.5 feet like sawtroll and others said.
It reminds me, I had a professor in college who had to hold her diameter tapes at eye level. I think she was about 4'-10" tall.

 

[Gologit]

If you're like me, you don't measure trees. You just look at them and know what the size is.
I'm usually within 3/10 of an inch on diameters and 3-5 feet on heights.


DBH is measured at shoulder height only when you're a little shorter than average.
Breast height is 4.5 feet like sawtroll and others said.
It reminds me, I had a professor in college who had to hold her diameter tapes at eye level. I think she was about 4'-10" tall.

Wow...you can really estimate tree diameter within 3/10 of an inch? Thats amazing. Where did you learn such a skill? Or is it just a natural talent? I"ve seen guys who've worked in the woods all thier lives,foresters and timber cruisers and such,who couldn't even come close to that. Please share with us the secrets of such an unusual ability. And then prove you can really do it.

 

[oldsaw]

True, I believe it is defined as 4.5 feet, but not quite sure......:biggrinbounce2:

Depends on the height of the girl used and the effects of gravity. In other words, if you are using an 80 year old woman who is 4.5 feet tall, DBH could be under 2 feet...:jester:

Mark

 

[Fumbler]

Wow...you can really estimate tree diameter within 3/10 of an inch? Thats amazing. Where did you learn such a skill? Or is it just a natural talent? I"ve seen guys who've worked in the woods all thier lives,foresters and timber cruisers and such,who couldn't even come close to that. Please share with us the secrets of such an unusual ability. And then prove you can really do it.

I sense more than a little sarcasm in your post, but I'll give you a serious reply anyway.
I worked with the Forest Inventory and Analysis (FIA) program spending all day every day measuring trees. An FIA quality assurance forester samples the FIA field foresters' plots and checks them on the ground. Missing a diameter by 1/10 of an inch is a point off their grading scale. We measured every single tree, so when I left the job I was pretty good at estimating diameters.

Foresters and timber cruisers aren't that accurate because they cruise timber on 1 or 2 inch DBH classes. They don't need to know if a tree is 13.2", they just need to know if it's 13 or 14 inches.

I'd be glad to have you quiz my occular estimation if you want to come to Rocky Mount, NC.

 

[STIHL-KID]

Depends on the height of the girl used and the effects of gravity. In other words, if you are using an 80 year old woman who is 4.5 feet tall, DBH could be under 2 feet...:jester:

Mark

You pose an interesting and humorous point about DBH......... :hmm3grin2orange:

 

[Vman]

quick, simple. not total precision, but a good estimate........
i made a 45 deg angle out of 2, 2 foot long aluminum rods (u can use anything, just need to be a 45 deg angle). step back 20 or 30 ft from the tree (can be more or less..whatever u want), hold one of the rods vertical with the tree and lift of the angle u made till the top of the angle is even with the top of the tree, now follow the 45 deg angle towards the ground using an imaginary visual line to see where the angle would meet the ground. this is where the top of the tree will land when it falls......now u can measure that point back to the trunk of the tree and get your tree height.
simple, but works quite well.

 

[blis]

Depends on the height of the girl used and the effects of gravity. In other words, if you are using an 80 year old woman who is 4.5 feet tall, DBH could be under 2 feet...:jester:

Mark

Is DBH measured with bra's or without ??

 

[turnkey4099]

Is DBH measured with bra's or without ??

I was wondering if perky or... mattered.

Harry K

 

[retoocs555]

If you're measuring a lot of trees a d-tape and clinometer are nice.

 

[bump_r]

Of course, take a circumference at that height and divide by pi (3.14),
to get dbh.

Not sure about elsewhere. There may be a metric equivalent.

What is the metric equivalent of pi?

 

[blis]

What is the metric equivalent of pi?

quess what... pi is pi everywhere! as in pi ~3.14

 

[SawWitch]

quess what... pi is pi everywhere! as in pi ~3.14

That's right.

 

[smokechase II]

sorry

I meant metric equivalent of the 4 1/2 foot distance.

I thought that there might be a 1.5 meter or similar.

 

[maveric944]

quess what... pi is pi everywhere! as in pi ~3.14

i wish, i'm starving, steak and mushroom please :help:

 

[SawTroll]

I meant metric equivalent of the 4 1/2 foot distance.

I thought that there might be a 1.5 meter or similar.

About 1.37 - I believe.....

 

[smokechase II]

dbh from America

I never thought of dbh's origins before this thread.

Why did dbh not originate in Europe?

Gifford Pinchot went there to study forestry. Not the other way around.
I would have thought that dbh should have been developed and standardized early on.

If dbh is universally based on feet, not meters, means that somehow it got started in the US or perhaps Britain or?