White Fir fire killed failure rates

[smokechase II]

Good of the order information.

"Here are some data on failure rates of firs and pines burned and killed in the 2003 Link Fire on the Sisters RD/Deschutes National Forest:

1) 26% (24 of 92 trees) of the killed white firs failed (broke) in 3 years.
2) Mean percentage of total tree height broken was 67% in 3 years (only 33%
was left standing)
3) 70% (64 of 92) of the killed white firs failed in 5 years.
4) Mean percentage of height broken was 71% in 5 years.
5) Dbh or height didn't seem to matter except for the 5-15 in. dbh trees
which tended not to break as frequently.
6) 29% (6 of 21) of the killed ponderosa pines failed in 3 years.
7) Mean percentage of height broken was 78% in 3 years.
8) 52% (11 of 21) of the killed ponderosa pines failed in 5 years.
9) Mean percentage of height broken was 74% in 5 years.

Although almost no trees failed at the base (root collar or uprooted), they
are "chunking down" but in big chunks (67 to 78% of their total height). It
appears that our "imminent failure potential" call for old dead trees (>5
years) is a good call, especially for fire-killed white fir. This is only
one look in one area, but it is a start.

USDA Forest Service"

 

[joesawer]

That is some useful data. It inspires a few questions.
What is the moisture and tempeture like in that area? What is the average moisture in the standing dead trees? What kind of micro organisms are causing the decay?
In my experience, burn kill trees often do not decay as fast as beatle kill trees.
Here in the high, dry, southern mountians, the decay and faluire is not near as fast, and it is often that the trees fail very close to the ground first. They are often termite eaten very bad at ground level but still have sound heart wood just a few feet up.
One thing I have noticed on tree failure is that the major rot can happen at randem places in the tree, but if you see a stand that has a lot of snags broken at a certian place, you can expect most of the trees to have major decay in the same area.

 

[2dogs]

sc II that is very useful info. Can you please provide a link to the entire article?

Dang, I can't rep you.

 

[smokechase II]

hunting

I'll go hunting for the entire article.

Will post if I can get it, which I think I can.

--------------------

The area of the Link fire is on the eastside of the Cascades but it is fairly wet there. I'm going to guess it gets 50 inches a year at the higher elevations of that fire. That was a guess.
I think I can look on the GIS, that has a rainfall layer, match its colors to the fire and come up with a decent rainfall number.
Temps are certainly cooler. Most days of the summer I'll guess that high temps F would be 55-80 when down lower you could see 15-20 degrees higher. I'll list fire high and low elevations.
For the most part these white fir have been killed by tussock moth and similar, not beetles.
The white fir fail throughout the stem. They are especially dangerous to fall and their rotten spots can easily ignite if the POI(ignition) is above 50%.

Whire fir should be held in a completely disrespectful attitude with regard to the speed that they rot.
They are dramatically more dangerous than dead Pine.

 

[smokechase II]

Sorry

Got this message after asking for a report:

"There is no report or published paper with these data; these are raw data
that I just collected this summer and included in the e-mail message. The
overall study is in press in WJAF but it doesn't include these data. We
will continue to follow the plots and eventually publish the fall-down data
over many years. Hope this helps?"

It will probably be many years before anything is available.

 

[joesawer]

That would be a very hard report to make accurate and useful.
Today I cut two fire killed pines, that are almost five years dead (Old Fire, Oct 2003). They where growing side by side almost co-dominant, and very limb locked. One was very sound and one was about the consistency of a dry sponge. The only difference in their environment that I could see is that, maybe, one was shaded more than the other.