Environment & Science
5:27 pm
Tue August 14, 2012

Michigan DNR plans to harvest healthy ash and beech trees before disease sets in

Forests throughout Michigan are undergoing big changes as millions of beech and ash trees are killed off by pests and disease.

Beech Bark Disease and the Emerald Ash Borer first arrived in Michigan around twelve years ago.

Both problems continue to spread, but many forests still have healthy trees in them.

Foresters from the Michigan Department of Natural Resources and Michigan Tech are taking a closer look at more than 30,000 acres of state forest land.

Andrew Storer, professor of forest and insect ecology at Michigan Tech, said the plan is to harvest healthy stands of ash and beech trees before they’re affected.

"If it's consistent with the management objective of the stand, then removing resources that you know are not going to persist until the next cutting cycle makes a lot of sense just in terms of getting the value out of those trees while they’re still in the forest," said Storer.

Storer said harvesting these trees now can also help forest ecology.

"It helps the forest by getting a head start, if you like, on what the future forest is going to be, and so by removing trees now and getting the value from that, we’ll start to see what the regenerating forest is going to be, and through management be able to direct that regeneration toward species that are going to be successful in the forest in the future," said Storer.

In a press release, the Michigan DNR said the goal is not to remove all beech or ash trees in these forests, but to thin them to a healthier level.

"We are using criteria including proximity to the nearest infested site, infestation, size, density and quality of trees, and accessibility, in order to prioritize which areas need attention," said Bill O'Neill, chief of the DNR's Forest Resources Division, who also serves as state forester. "Considering other factors important to maintaining healthy forests, harvests are being scheduled to remove the beech and ash and regenerate the stand to a desired, productive species mix. The goal is not to remove all beech or ash, but to reduce them to a level that the mortality will not significantly impact the quality of the remaining trees or the productivity of the forest."

Researchers started surveying state forest land for this project last June and plan to continue surveying through next summer.