The Blight Plight of the American Chestnut

[Music] there are many species of chestnut trees around the world but the American chestnut species is almost completely extinct in the wild before the turn of the 19th century a disease known as kinexa parasitica or more widely known as Chestnut blight wiped out more than 99% of chestnut trees Chestnut blight is not native to North America so it ravaged the chestnut trees in America that had no resistance to the fungus former har biological historian Donald Davis said that many scientists believe that the disease came from Japan it took really another decade or certainly half decade before people began really really agreeing that yes the fungus was an Asian fungus from Japanese Chestnut trees um and really the The Smoking Gun was a trip that Frank Meyer he was a famous plant Hunter Frank Meyer had gone to Nico Japan and he saw the fungus growing on Japanese Chestnut trees in niik Japan and he sent shipments of the Twigs back to the USDA and when the USDA plant pathologist analyzed the fungus on these trees and looked at it they said yes definitely this is the same fungus that our American trees have there are groups of scientists and researchers that are currently focused on the restoration of the American chestnut tree in the wild a key group is the American chestnut Foundation this nonprofit organization has been working on this project for around 40 years and are still making major efforts to restore the American chestnut the foundation spans multiple states with each state having its own chapter Barry biology Professor Dr Martin cipolini said that there is a lot that goes into the foundation now what kind of organization it is it's it's there's all sorts of components to that so there's basic research there's citizen science a lot of involving of volunteers there's public education and Outreach there's a grant seeking and donation to get money to to to uh support the various types of projects uh so it's a really quite a diverse um a diverse organization it's also divided into State chapters so because American chestnut occupied essentially the entire Eastern Seaboard from Maine the hallway down into Mississippi and even down into Florida perhaps um there are State chapters developed in each state that are sort of responsible for developing the program towards Restoration in their own State one of these efforts is the crossbreeding of Chinese and American chestnuts as Chestnut blight came over from Asia the Asian species of chestnut referred to as Chinese Chestnut are resistant to the blight their goal with these hybrid trees is to have a tree that looks and grows like the American Amer Chestnut but has the blight resistance of a Chinese Chestnut some people might wonder why they are crossbreeding chestnuts instead of just planting Chinese chestnuts since they are already resistant to the blight well Dr Hill kdock the professor at the University of Tennessee in Chattanooga said that Chinese chestnuts can't survive in an American Forest it's not because we don't like the Asian chestnuts they're perfectly good chestnuts um but because they're not well adapted to the forest here so I'll give you an example the Asian species none of them Japanese Chestnut from Japan or the three Asian three Chinese species none of them makes a tall enough tree to compete with the Oaks and the Elms and the ashes and the beach and the Maple and the other kinds of trees we have in our forest here so the the forest type here in Appalachia and you know in the Southeast the forest canopy is very high so to compete in that canopy you have to be a Tall Tree the American chestnut species C dantata has another characteristic which allows it to survive in the forest here which is that it's shade tolerant in other words it can live as a shrub in the understory for many years for decades maybe Forever Until It has an opportunity to grow quickly up into the canopy and none of the Asian species can do that so they're not shade tolerant so if you planted Chinese chestnuts out of the woods they would perish and we know that from nearly a hundred years of observations and experiments the crossbreeding program is incredibly active especially during the summer many chapters have their own Orchard which holds the chestnuts and each Orchard is well documented with the parents and blight resistance of each tree then they look at which trees have the qualities they want once they find these trees they bag the female part of the plant so that it cannot be pollinated by other trees then they collect pollen from the male part of the selected trees also known as the catkins some of the pollen is used on their own trees but a lot of it is sent out to different chapters so they can pollinate their trees Junior biology major and Chestnut researcher Anna Rose goes into more detail so the summer was a lot of Orchard maintenance and all of that but some of the really cool things that we got to do was um we got to pollinate our trees so we um we go out um and we have big trees and Orchards that are producing little flowers and we put bags over the flowers because um they're wind pollinated and insect pollinated so it prevents the trees from pollinating each other so then we can go in take the bags off and we have our own pollen that we collect from catkins from other trees and we know the lineage of these trees all the way back um exactly what their jeans are how much American is in these trees how much Chinese how resistant they are are um and so we get to choose the pollen that we put on these trees specifically so then we when we get the seeds we know exactly what this trees with these trees lineage are the bags are left on so that they can harvest the chestnuts come August then they will process the Harvest chestnuts before planting them in labeled pots so that they can grow new saplings before that the saplings from last year are tested for blight resistance the researchers perform a small stem assay an experiment in which they expose a branch of the sapling to the chestnut blight then they observe them to see how far the chestnut blight has spread to determine which of the saplings has more blight resistance Donald Davis said that compared to today old conservation efforts were highly uncoordinated well back then um it was sort of a hodge pod kind of everything with the kitchen sink kind of approach where they did everything from apply mud to the trees they were actually there was some some examples of them putting bottles of chemicals hanging from the trees and they would put chemicals in the bottles and then the bottles would go into the bark into in into the tree and um you know th those methods didn't work but they tried everything burying Nails around the trunks of the trees um and of course um what they did at the New York panical Garden was sprayed in with fungicides and that was generally what most people did was take the fungicides of the day spray the trees heavily and that did work for a while but generally after several large rains the fungicide would wash off the fungus would attack again and usually within a year the the trees would show signs of the BL some may wonder why we need to restore the American chestnut tree back to the Southeast region of the US like many other endangered species the American chestnut does a lot for its environment one of these things is that produces nuts annually while mini trees produce a large number of nuts one year and don't produce them for another three chestnuts produce nuts every year making a reliable food source for the Wildlife their nuts are also more nutrient Rich than most other nuts they also absorb and store more carbon dioxide than any other tree this is only some of the factors to why the American chestnut should be restored to the wild Dr Martin cipolini said that Chestnut trees were incredibly impactful in multiple ways but based upon the characteristics of the tree and their abundance we can kind of get really good guesstimates of how important they were they were very abundant they might have been 25% of all the trees in the forest they produce large fruit crops nut crops every year that's kind of unusual something like an oak may only produce a good crop every few years but American chestnuts every single year they produced tall straight trees that were great for for Timber production the wood was rot resistant the bark contained tannin that could be used for tanning hides and that sort of thing so it was absolutely incredible biological resource human resource an economic resource for the folks in the Appalachian Mountains um basically their their entire economies were based around the chestnut it really a really important tree species for them the American chestnut Foundation is making strides to restore the American chestnut to the wild with many different experiments and ideas pushing for the same goal their conservation efforts are very important for our ecosystem and are a major step to heal our planet with Viking Fusion news I'm Lou Durand

Channel: VikingFusion

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Length: 9min 49sec (589 seconds)

Published: Fri Dec 01 2023