American Chestnut only occurs in Canada in southern Ontario in the Carolinian Forest zone
Chestnut blight probably arrived in North America in the late 1800’s
by the 1950’s, virtually all mature Chestnuts in North America had been killed by the blight
today, American Chestnut occurs primarily as sprouts from stumps and roots, and occasional saplings and larger trees
in Ontario, there are a small number of large seed-producing trees that do not appear to be affected by the blight
these apparently-resistant trees may be very important to the recovery of the species
the disease was brought to North America on imported Japanese Chestnut
Chestnut blight attacks twigs, branches, and the trunk
the blight causes cankers that eventually girdle and kill the tree
infected trees show disfigured bark and often areas of small orange bumps growing through the dead bark
the fungus has killed most mature trees in North America but they often resprout from the base
Can live a number of years and may produce some viable seeds
Impact on Trees
the American Chestnut tree was an important forest species in southern Ontario that provided valuable wood for furniture and nut crops that were used by wildlife, Native Americans, and early settlers
in much of the eastern US, American Chestnut was the dominant forest tree and its loss had a profound impact on deciduous forests
American Chestnut is considered Endangered in Canada due to the impact of the disease
What can be done to control this tree killer?
there is no known cure for Chestnut trees infected with blight
early studies in the US focused on a search for trees with natural resistance to the blight
none were found that had sufficient resistance
more recent studies have involved hybridization with Chinese Chestnuts that are not affected by the blight
such hybrids may allow reforestation of ‘American-like’ Chestnuts, but they will not be true American Chestnuts