Wednesday, August 27, 2014

Counting Chestnuts

Castanea dentata
On Monday, I had the pleasure of joining Mike and Kieu Manes for a day of American Chestnut (Castanea dentata)counting. I had sparked up a conversation with Mike at the Festival of Wood when I spied his NY/NJ Appalachian Trail Conference shirt. We talked about the AT, MST, the book, and then about the American Chestnut when I learned that he and his wife were involved not only with the Appalachian Mountain Club and local AT conferences but with the American Chestnut Foundation. I soon met Kieu who was excited to see Pennywort featured in my book, which she is familiar with from her native home, Vietnam. In Vietnam, Pennywort juice is a well known drink called nuac rau ma. It is made from Centella asiatica, a different plant from the species of Hydrocotyle described in my book, but still closely related. Anyhow, the three of us soon found ourselves making plans to share some plant knowledge.

Kieu and her measuring device, an important tool used when counting the Chestnuts.
Mike measuring the distance of an American Chestnut from the Appalachian Trail
So on Monday morning we met at Fox Gap on the Appalachian Trail, which sits just outside of Stroudsburg, PA on Route 191. Mike and Kieu presented me with an American Chestnut counting kit and gave me instructions of just what we'd be doing. We were to walk the AT slowly, headed south towards Wolf Rocks, and record each American Chestnut that we saw along the way that stood at least 3 feet high and within 15 feet of the trail. We could admire the others but this is a mission   called the AT MEGA Transect Chestnut Project, in which the AMC is teaming up with the American Chestnut Foundation to find out just how many trees are surviving on the AT. However if we spotted a tree which had trunk that was 13 inches or more in diameter, we were then to make special note of it, and get up close and personal recording as much as we could about it.

Note the orange bumps on the trunk of the tree - this is evidence of the blight (Cryphonectia parasitica) that infects and kills the American Chestnut.
Why spend the whole day counting American Chestnut trees? Because they are a nearly extinct species. Nearly 25% of all trees in the Appalachian Mountains and from the Piedmont west to Ohio River Valley, its once thriving habitat, were at one time American Chestnut. In Pennsylvania, the American Chestnut was even more prolific, comprising 30% of all hardwoods. This tree was prized for its rot-resistant, tannin-rich wood, which was also straight-grained and grew rapidly, easily reaching over 90 feet in height and nearly 10 feet in diameter. Not only was the lumber excellent for building, but its tannins were used for tanning leather, and the nuts of course were a commodity as well, reportedly more delicious than those of the European Chestnut (Castanea sativa) which we enjoy today.

It was in 1904 at what is now considered the Bronx Zoo, that the blight was first discovered. This fungus, believed to have originated from Asia and accidentally transported here on infected lumber, is now dubbed the American Chestnut blight, however it's scientific name is Cryphonectia parasitica. Within 50 years, nearly 4 billion trees had been killed and this is the state in which we find the species today.  New American Chestnut trees will sprout from old roots as well as from seed, however, in almost all instances, the tree will inevitably be destroyed by the blight which enters through natural fissures in the bark which form on the tree with age or through other points of entry such as a snapped or severed twig. Once inside, it spreads through the vascular cambium, killing the this tissue and surrounding tissue, and it becomes impossible for the tree to transport nutrients. It is incredibly rare for a tree to survive beyond 20 years of age. 

The blight enters through naturally occurring fissures in the bark of older trees (fissures can be seen to the left, orange blight to the right) 
There are however small populations of healthy American Chestnuts out west that survive as well as in Michigan and dappled throughout its original habitat in the Appalachian Mountains. Those out west and in Michigan are a result of pioneers carrying the seeds and planting them for eventual lumber harvest or as a food source. The surviving populations are a result of fortunate isolation, protecting them from the spreading fungus.

Kieu walking Wolf Rocks on the AT
However, I think recording nearly 170 American Chestnut within less than 2 miles of trail is pretty darn good. This count does not include all the smaller saplings we saw and those that stood more than 15 feet from the trail. A good number of these 170 were clearly infected with blight and it is most likely that the younger ones that were not yet showing evidence of infection were already infected or will be in due time. We saw none that were 13 inches in circumference, however we did see several that were rather tall and slender with a beautiful spread of green leafy branches.

I imagine I have hiked blindly by many more American Chestnuts than I have ever known. Down south, I'd often pass a tree that I suspected to be American, however I knew it was just as likely to be a Chinese Chestnut (Castanea mollissima) which bears close resemblance at first glance. However, up here in the northeast, our woods possess very few Chinese Chestnuts. I imagine they would be found at old homesites but they have not naturalized here as they have down south. European Chestnuts would also have to be planted to be found within our woods. Therefore up here, if you spot what looks like an American Chestnut, it is a strong likelihood that it indeed what you have! That is as long as you pay attention to a few key features.


A typical looking American Chestnut Leaf

The leaves are alternate, longer than they are wide and have a tendency to droop. The margins (outer edge of leaf) are toothed, with each tooth appearing sharply hooked. The bases are V-shaped and the apexes (leaf tips) come to long sharp points. The tops of leaves will be a dull green in color with light green undersides and free of hair. Chinese Chestnut leaves are more oval shaped with rounded bases and shorter pointed apexes. Chinese Chestnut teeth will also be less sharp and not hooked, the undersides of leaves whitish with fine hairs.

Chestnut Oak Leaf (Quercus montana)
The more likely tree one could confuse with American Chestnut is a Chestnut Oak (Quercus montana), which is also a member of the Beech family (Fagaceae). However the margin of a Chestnut Oak leaf will have rounded teeth or lobes and will not bear sharply pointed apexes.

An American Beech leaf
Another possibly lookalike would be the American Beech (Fagus grandifolia). However you can see that the teeth are not as sharply hooked along the margin and that the apex is more short-pointed. Overall the American Beech leaf is also more oval shaped and less elongated.

There are of course other members of the Beech family that could also look similar such as the Allegheny Chinkapin (Castanea pumila), but those leaves will be glossier on top and bearing white hairs on underside. The teeth along the margins will be short and non-hooked. This tree is also less likely to be found as far north as northeast Pennsylvania.

The American Chestnut Foundation has been hard at work breeding Chinese Chestnuts which have a natural resistance to the blight, with American Chestnuts to build up the American Chestnut's resistance. The chestnuts that survive are then bred again with another American Chestnut, therefore increasing the percentage of American Chestnut genetics within the tree as well as the resistance. The foundation presently has a line of chestnuts that are 94% American. They are calling these their Restoration Chestnuts. With these efforts, perhaps one day future generations will again be able to look out over a vista such as this and see the tops of American Chestnuts.

The view from Wolf Rocks
 To learn more about the American Chestnut Foundation, check out their website at www.acf.org. And to my Asheville folks...do you know that this foundation's headquarters is located on Merrimon in Asheville? Thank you so much Mike and Kieu for sharing your knowledge with me! I can now spot an American Chestnut more than 15 feet away and clustered amongst many other trees! Keep sharing. What an awesome day.

Mike and Kieu Manes - American Chestnut extraordinaires




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