Chestnut Trees Are Returning to Forests

american chestnut was one of the dominant trees in the eastern hardwood forests it was a fast growing tree one of the fastest one of the largest that chestnuts could reach 80 feet tall and three four five feet in diameter it was a really big tree and it produced this straight grain rot resistant wood made it great as a timber product but american chestnut also being a dominant part of the ecosystem served a lot of ecological functions it was important for water and nutrients and carbon sequestration one of the most important things about american chestnut was that it produces large mass of nuts annually so tom how did the blight actually arrive in north america well blight was actually accidentally introduced on some japanese nursery stock it spread onto some of the american chestnut trees in new york in 1904 and it took about 50 years for for the chestnut plate to spread across the country and effectively wipe out american chestnut as an overstory tree it's considered one of the worst ecological disasters in our time wow can you tell us a little bit more about this space and a little bit more about the organization that you work with the american chestnut foundation right well this space is called the fortunes cove orchard this is actually land that is managed by the nature conservancy they're one of many partners that work with my organization now the american chestnut foundation is a non-profit organization that started back in 1983 and we have a staff of less than 20 people all of our work is done by volunteers and members who help us we have state chapters that put in orchards just like this we have hundreds of them and so part of what the work that you're doing here is you actually have a research orchard where you're testing and evaluating the blight resistance on these trees absolutely japanese and chinese chestnuts are they can tolerate blight gotcha so those trees have the genetics to be resistant to blight the american chestnut trees don't well what we what we've been working on is getting those resistance genes from those asian trees by hybridizing them with the american chestnut tree that's great well then what we do is we back cross them to americans right we want to try to make the trees as american as possible so we don't want a 50 50 hybrid so those trees are then crossed with an american their progeny our test for blight resistance the best ones are then grown up they're crossed with an american we screen them again and we keep doing that so this orchard that we're standing in right now all these trees had one tree that's an advanced generation blight tolerant tree crossed with a wild american tree that's fantastic and what is the difference between the asian chestnuts and the american chestnuts in terms of the what the leaves look like and the burrs i brought in a sample of a of a pure chinese chestnut tree and this would be the one that's resistant to chestnut light then this is a wild type american chestnut tree it's very different they're totally different not just in the way they look but in the way they grow in the forest their habit their competitiveness everything's different about these trees well they're similar enough that they're sexually compatible so we can cross them with each other that makes our breeding program possible so what we're trying to do is make a tree that looks like this but has blight resistance that's similar to this we might not get our trees as blight resistant as chinese chestnut but we're going to get it close yeah yeah so i is are these the cankers themselves and it looks like the tree is kind of cordoning them off yeah that's right so what we do is we come in when the trees are about five to six years old and we actually put a little hole in the bark and we put some blight inoculum in the tree and then we see how the tree responds and you can see this tree in particular see these these blade cankers everywhere where blight gets in the fungus starts to grow in the cambium and if the blight had its way it would grow all through the cambium through the vascular tissue girdle the tree and kill it what this tree is doing is every time blight is introduced it walls it off with this callous tissue and it keeps the blight from spreading and you can see all of these cankers it's just callous tissue the blade has been walled off it's not allowed to spread it's not allowed to kill the tree the vascular cambium under these blight is fine these are superficial cankers so if you have a tree that's blight resistant enough that it can actually put its energy into growth then you're going to get a competitive american tree back in the forest that's wonderful yeah now this is the harvest season so why don't we go take a look at some of the burrs oh sure come on i've got a tree over here i can show you great so chestnut was really ingrained in the fabric of appalachia as well yeah that's right you know back in the old days folks would go out chestnutting they would harvest bushels of chestnuts and bring them home to roast but you know as the rural appalachian farmers that really depended on this tree they would send their hogs out into the forest and let them fatten up on these juicy chestnuts right before they take them to market you know american chestnut was an important ecological tree but it was certainly really important to rural appalachian folks as well yeah well this tree is absolutely loaded yeah this is one of the best times of year for us this is the time when we come out and we start pulling the burrs off the trees get them all processed we put the seeds in the refrigerator and leave them there for about a month or so to scarify and then we're ready to pot them up or plant them in the orchard i brought a little show and tell if that's okay i just wanted to show you some examples of some chestnut seeds i wonder if you notice the difference between these yeah much larger versus much smaller there's a lot of folks who grow chestnuts for the sake of producing a commercially available culinary seed they're always going to be a chinese chestnut but for our work to get chestnuts back into the forest and to make them suitable for wildlife like blue jays and turkeys and all the animals that used to eat chestnuts we need something that's just like the old american chestnut tree so let's take a look at some of these burrs let's do it yeah that's great grab my handy pull pruner here let me get this one here that looks pretty good there it is it's great and if you can use your gloves to pry some of those open sure yeah let me get up my seeds again hold that open i'll pull one out there's my american there's my chinese and here's one of our hybrid chestnuts take a look at that right we really got it just right this tree is indistinguishable from the pure american chestnut wow so so obviously you guys are doing a lot as an organization do you have other partners that you're also working with yeah to achieve some of the desired outcome yeah beyond the fact that we work with a lot of volunteers we work with a lot of organizations for the breeding program in our region which we think is very advanced we're doing some really great work and part of that is because of our partnership with the virginia department of forestry they've been doing a parallel chestnut breeding program for more than 50 years and what we're doing now is we're taking our best trees and their best trees and we're crossing them if we can get all the best genes from all the trees in our program and all the best genes from the trees in their program and combine them we'll end up with a superior chestnut tree one that has really great blight resistance a very american tree later this year we're going to start planting those seedlings in this very same orchard we're going to refill this orchard up with all new seedlings starting next year over the next 10 years we'll have 100 trees in this orchard and when they start producing seeds we'll start planting the tree back in the forest we're that close one step away from reintroducing american chestnut so tom this is really impressive work that's all going towards restoration of american chestnuts what are some of the other applications for different tree species under threat ah well that's a good question too our thought is if we can figure out something as complicated as chestnut blight and actually be able to restore american chestnut to the forest using genetic breeding well then we could apply that same technology to other trees in fact we're doing it now other researchers are now doing genetic breeding programs with ash trees to make them resistant to emerald ash borer hemlock trees white pine trees out in the west coast all over it'd all begin with the work that we're doing with american chestnut so that as we keep seeing these pests and pathogens showing up which is unfortunate but it's the way it is maybe in some cases genetic breeding will be a solution to that and we won't lose all our tree species and we can conserve healthy forests thank you so much for having us out it's really inspirational work and we just wish you all the success in restoring american chestnut to the landscape i'll tell you what it's my pleasure keith this is the best job in the world well if you've got time let's harvest this tree and eat the nuts sounds good

Channel: VPM

Views: 1,095,134

Keywords: Virginia, VPM, VHG 2108, Virginia Home Grown, Tom Saielli, The American Chestnut Foundation, chestnut blight, hybridize, backcross breeding, American Chestnut, Chinese Chestnut, Fortune’s Cove Orchard, The Nature Conservancy, Keith Nevison, chestnut tree, chestnut, american chestnut tree, chinese chestnut tree

Id: DbrY-J0bpto

Length: 8min 34sec (514 seconds)

Published: Sat Feb 19 2022