american chestnut - new trees found!

[rebocardo]

http://www.ajc.com/news/content/news/science/stories/0519chestnuts.html

Since you have to join (free) to get the article, I will post some of it (fair use) for conversation.

"
Cluster of rare chestnut trees in Georgia
Stand dodged fungus that killed hardwoods

By ELLIOTT MINOR
Associated Press
Published on: 05/19/06

A stand of American chestnut trees that somehow escaped a blight that killed off nearly all their kind in the early 1900s has been discovered along a hiking trail not far from President Franklin D. Roosevelt's Little White House at Warm Springs.

The find in west Georgia has stirred excitement among those working to restore the American chestnut, and raised hopes that scientists might be able to use the pollen to breed hardier chestnut trees.

"There's something about this place that has allowed them to endure the blight," said Nathan Klaus ..."


All we need know is to hear gas is back under $2.00 a gallon :-D

[Ron Wenrich]

It says "The largest of the half-dozen or so trees is about 40 feet tall and 20 to 30 years old". 

I've seen trees that size in the woods, with a dbh of about 12-14".  Usually they die, since the blight is in the root system.  There is some resesitance that does build up over time.  The blight came through this area about 90 years ago.  I talked to a state official a good number of years ago who felt that it would take nature about 400 years to evolve resistant chestnut.

I would suspect that these trees are merely a next generation or two from the blight infestation in the area.  The blight was in the southern part of the range in the '50s, and chestnut lumber was still being salvaged in the mid-70s.

An interesting find, but I was hoping for trees that were up in years, like the ones in Wisconsin.

[rebocardo]

Yes, a tree in the 30"+ DBH range would be great, who knows, maybe there is and they have not told anyone  ;)   I know I would love to plant a few of the "true" seedlings.

[Riles]

The blight is actually a canker disease, spreading under the bark. Once the cambium layer is girdled, the stem dies. American chestnut is not in immediate danger of extinction because of root sprouting. The root systems are intact and the sprouts grow until they reach the point the bark is compromised, either from insects, mechanical damage or the bark splits as the tree ages.

Chestnut blight is considered a superpathogen. It kills the tree very quickly, has multiple fungal forms of spreading, and has plenty of alternate hosts that they are sublethal on. In other words, it's everywhere and kills the American chestnut tree before it can reproduce and pass on any genetic resistance. Resistance cannot build up over time in any given tree, it's either there (like in Chinese chestnuts) or it's not. And since the blight kills off the root sprouts before they can reproduce, it's highly unlikely they will evolve a resistance on their own. In nature, what would normally happen is the pathogen would kill off all it's hosts and die, or evolve to become a less virulent form. In this case, it's less virulent form just happens to be on a different host, so there is no evolutionary pressure to change.

Although stands of chestnut have been found before, no one believes they have an inherent resistance. They're just lucky the blight missed them or environmental conditions are such that the fungus died off locally and the stand has not been reinfected. That said, these stands are valuable as a genetically diverse stock (even without blight resistance) for the breeding program. The fact that this stand has seed is what is surprising. What normally happens is the seeds are planted and the trees exposed to blight and die (confirming no genetic resistance).

It is my understanding that there are stands of chestnut out west somewhere outside of the range of the blight. Whether they are in a secret location or not, I don't know, but the more human traffic in the area, the greater the risk of contamination.

The breeding program by the American Chestnut Foundation is very interesting. Cross an American with a Chinese and test for resistance. If it lives, cross it with an American and test the progeny for resistance. If it lives, cross it with an American and .... Eventually, in theory, you get a product that is entirely American chestnut except for the gene for blight resistance. Not like doing heredity studies in fruit flies, where you get your results in a couple weeks. It may take 400 years, but it wouldn't happen in nature.

By the way, Sudden Oak Death has pathologists worried because it has many of the characteristics of a superpathogen. Ironic, because oaks were the primary beneficiaries of Chestnut blight and Dutch elm disease.

The blight:  http://www.forestpathology.org/dis_chestnut.html

The ACF:  http://www.acf.org/

[Paschale]

Good post, Riles.  Thanks for the info.   :P

[Don P]

I have seen several locally and elsewhere make it to nut bearing age. Not sure that nature couldn't get lucky and make a resistant seed. Around here it seems like maturity, nut bearing, and bark splitting all happen about the same time and the fungus shows in the cracked mature bark swiftly.
From what I understand resistance is carried on more than one gene, complicating the back crossing.
I have seen some good sized trees in WI. One of our clients wrote about a year ago that one I had shown them had blown over  :'(.
One thing I read that makes some sense. When the blight got started we began heavily harvesting, since they were goners anyway. The writer maintained that if there were resistant trees out there, we harvested them. Food for thought anyway  ???.

[etat]

I just cut a chestnut tree about two weeks ago that still had seed laying on the ground from last year.  THe ONLY one that I know about anywhere around here.  I understand the guy who works for me, his Grandad planted it years ago.  It wasn't very big, probably only about 16 inches or so around  and was leaning over an under a LOT of tension.  One pretty good sized limb had done split off from it from a storm.  We cut the main trunk and left a really big sprout that was growing beside it that was standing up straight. 

[thecfarm]

I saw the article in todays paper.What a find.

[sawmill_john]

Out here in oregon the Chestnut is not native but we have some old trees that have grown to 5' and up at the butt, I cut one a few years ago that came from an old part of Portland Or, I counted out the rings to about 100 years old, it was between 4' & 5' in diameter (oval) people out here just don't know about the chestnut, I have been able to sell some of the lumber but most people don't even want to look at it, or think its oak.  heres a mantle I made for my sister inlaw.

the pictures don't do justice to the wood, I was very happy with the way it turned out.

[oakiemac]

Thats pretty John. The Chestnut looks like it has a little curl figure.

[rpg52]

I haven't been back in a few years, but there were some American Chestnuts in the town square in Chico Calif. (along with some Elms).  It was suggested in a radio item I heard about the Georgia trees that the dryness of the climate had something to do with their survival.  That might be the reason they are surviving in Chico too.
Ray

[timberjack240]

i have a chesnut trurkey striker... its wrokin pretty good this year i called four in with it that i seen and worked a few i didnt get to see nothin else... it makes good strikers  ;D

[Phorester]

Going along with what Ron said, it is also not unusual to find American chestnut trees of this size in the mountains of Virginia, so I'm not sure of the nature of this article.  It sounds as if it was written by a reporter who really didn't know how many chestnuts there still are in the woods.

The trees mentioned in the article are about at the age when the blight hits them.  So I wouldn't be surprised if they are not all dead from the fungus in 10 years.

[farmerdoug]

The American Chestnut is now beating the blight on the west coast of Michigan.

Proffessor Fulbright told us about a project in the 80's he did with money from the Michigan Nut Growers Association.  He inoculated a large group of trees on the west coast of Michigan.  In the nineties he dropped the project as the blight virus was not working.  He went back with another reseacher last year and low and behold the trees have started recovering nicely.  The inoculate only seems to work with the Michigan trees but hope is coming soon for the trees.

Farmerdoug

[WDH]

It is a majestic tree.  I can only hope that its lineage can be preserved.

[farmerdoug]

As near thbey can tell these are American chesnuts.  They were brought there by the PA dutch that moved there.
  The European chesnut has learned to survive the blight and now the American too.
Farmerdoug

[SwampDonkey]

Good post, Riles.  Thanks for the info.   :P

I'll second that. 

[SwampDonkey]

Around here we have a few very scattered disease free beech among very badly infected beech. The smooth ones, may be resistant or just lucky. But, then what about the seed produced from these possibly disease resistant beech? It's not controlled pollination in nature, and the stressed trees produce a lot of nuts. Which seed or new tree do you choose as the resistant one for future breeding or preservation programs?  Even if you got lucky and found two resistant trees, they would not be pure. It's like black bears for example. Most offspring are black, but there are some brown and some white (not albino) ones as well. :

[WDH]

What is the disease in beech?

[farmerdoug]

This is not a resistant tree but a virus that makes the blight livable for the trees.  The European chestnuts have been surviving for years now and the professor brought the virus back here to try it on trees in Michigan.  It is working but it takes awhile to get established as per what Riles said about the quick kill by the blight on growing stems.  The virus infected blight grows slower and takes a while to infect the fast growing healthy blight.

Farmerdoug

[SwampDonkey]

Beech Bark disease thread

I think the search function blew up.  :-\