THE LOCAL CLIMATE: Refuge worthy of a King

Pictured is the Ashdale Tree in Hants County.

By: Zack Metcalfe

At one time, the American chestnut made up a full quarter of all trees in the mixed deciduous forests of eastern North America, conquering canopies from southern New England north into Ontario. The King of the Forest, they called it, not only for its commanding stature but also its chestnut bounties and fine lumber.

This all changed in 1904, likely when a Japanese chestnut was planted in the Bronx Zoo, New York. With it came the chestnut blight, an ailment against which old world chestnuts possessed a natural resistance, but which was wholly new to the King of the Forest. This blight tore across the native range of the American chestnut like wildfire, killing upwards of 5 billion in the course of 50 years, all but ensuring the extinction of the species.

The only American chestnuts which survived this onslaught were those planted outside their native range, where the blight could not reach them, and perhaps no safe haven was more significant to the species than Nova Scotia.

American chestnuts never grew this far north, their seeds unable to survive our harsh winters, but if planted as seedlings they reached canopy heights just fine. As their counterparts were being devastated to the south, Nova Scotia’s refugee chestnuts offered the species a chance for survival. Two, for example, were planted at the Uniacke Estate Museum Park north of Halifax prior to 1815, one of which has since blown down. Another chestnut sheltered the streets of Bridgewater for a time, but died of its own accord and was removed. Another, in Hants County, is called the Ashdale Tree, planted in 1905 and believed by many to be the largest surviving American chestnut in Canada, if not North America.

As you might imagine, rescues have been attempted of this iconic tree. Before its death, conservationists attempted breeding the chestnut of Bridgewater with the Ashdale Tree, carrying pollen back and forth until viable seedlings were finally produced. Two of these were planted in the Halifax Public Gardens in 1967 where they can be seen to this day, and another three went to the Kentville Research Station that same year.

Bolder actions on behalf of the species have taken place to the west. The Canadian Chestnut Council and the American Chestnut Foundation have been attempted to crossbreed American chestnuts with old world chestnuts sometime now, hoping to produce as pure an American chestnut as possible but with the old world immunity to blight. Several such crossbreeds have been planted across Nova Scotia. These organizations have likewise been looking for natural blight resistance among whichever American chestnuts remain standing in their native range. Sadly, there are not many.

Another effort to preserve the species is considerably more direct and has seen tremendous success in recent years. It involves transplanting a gene from the common wheat plant into the American chestnut so the tree gains complete immunity to blight, making it potentially more resistant even than its old world counterparts. The project, spearheaded by the SUNY College of Environmental Science and Forestry, could produce upwards of 10,000 blight resistant American chestnuts for public distribution across its historic range in the near future. This is an extraordinary feat, which the public will need to take active part in.

So it might one day be possible to restore the American chestnut to its former glory, but whatever form the species finally takes, it seems certain to me that it will not be its original self, its genetic purity sacrificed for the sake of its survival, making way for an adjusted species wholly new.

I think this is a worthy goal and perhaps a necessary one, but it means the true American Chestnuts of Nova Scotia are relics in their own right, and are worth seeing before their time is up. For better or worse, some day there will be none quite like them. Having stood beneath the Ashdale tree, the Uniacke trees, the Halifax trees and those in the backyards of a few chestnut enthusiasts, I can say with confidence that their loss is a crying shame.

Zack Metcalfe is a freelance journalist, columnist and author active across the Maritimes. He can be reached at: zack.metcalfe@gmail.com.