Minnesota’s ash trees are as good as gone. That’s the sentiment of four Olmsted County officials, who are proposing the county start its own tree farm in preparation for the arrival of the hated Emerald Ash Borer in Minnesota and the subsequent disappearance of the ash. The argument is that the ash trees will, sooner or later, have to be replaced and that rather than paying a nursery $100 for a new sapling, the county could save a lot of money by growing its own.
The foreboding proposal hearkens back to a time when municipalities planted ashes to replace the devastated elm population during the 1970s. Nearly 20 percent of the trees in Minneapolis are ash, but the ash dominates more than our streets, parks and golf courses. Northern Minnesota has the highest concentration of ash trees in the country, according to the U.S. Forestry Service, and all species of North American ash appear to be susceptible.
The U.S. Department of Agriculture (USDA) is also preparing for the worst. The National Ash Tree Seed Collection Initiative has been established so that if the ash is completely decimated, a genetic base is available to re-establish the population. The seeds will be stored at the National Center for Genetic Resources Preservation in Fort Collins, Colo., and the Forest Service will X-ray collected ash seed to determine sound seed for storage.
The project may be just in time. The ash borer, a shiny green beetle that seeks refuge in the bark of the ash, originated in Northeast Asia. It has once again made its way in Michigan’s Upper Peninsula. The discovery of the ash borer in the U.P. is a particularly disheartening blow, as it was contained and eliminated after an initial infestation in 2005.
Most likely brought into the Upper Peninsula by foolish travelers who ignore warnings not to travel with or move firewood, the ash borer had to cross vast expanses of water from lower Michigan or Ontario to establish itself in the U.P. It would seem that opponents of the ash borer have two pests to deal with.
First discovered in southern Michigan, the ash borer has established itself in Ontario, Indiana, Ohio, Illinois, Pennsylvania, Virginia, West Virginia and Maryland. The ash borer is now threatening Wisconsin and Minnesota, the states with the largest ash populations.
There is hope, however. The USDA is studying the impact that three varieties of tiny gray Chinese wasps have on the ash borer. The wasps are attracted to the scent of the ash tree and lay their eggs inside the larvae of the Emerald Ash Borer, thus eliminating any chance of maturation. Using nonnative species to control invasives is not new, although certainly not without risk. But the approximately 1 billion ash trees in Wisconsin and Minnesota may be worth it.