Why am I seeing so many areas of dead trees around the state?

Invasive pest species along with several other environmental and human factors are contributing to the decline of our forest and urban tree resources in Michigan.

Dead pocket of trees along US-45 in Ontonagon Co. | Photo by Mike Schira
Dead pocket of trees along US-45 in Ontonagon Co. | Photo by Mike Schira

Traveling across the state there is evidence of high tree mortality which is raising concern. Some of these losses are individual trees scattered here or there, but in many areas there are occasionally large blocks of dying trees.

Some of these losses are natural. After all, trees are living organisms and do eventually die. Some of our native species, such as northern white cedar, are very long lived; but others, such as aspen and jack pine have relatively short life cycles. Overcrowding and old age eventually lead to some of the tree mortality we are seeing.

Human activity and environmental factors are also contributing to the death of trees. Improper road construction, soil compaction, liberal use of road salt and poor culvert installation and maintenance can be contributing factors. Wildfires and severe wind events also add to regional tree losses.

Although trees grow on a wide variety of sites, a change in water table, either via ponding or drainage, will many times cause the trees in the impacted area to die. For example, it is not unusual to see a lot of tree mortality around beaver ponds, and not all of it is caused by the industrious critters chomping down trees.

Trees experiencing prolonged periods of drought stress can reduce their vigor and make them vulnerable to insect attack and diseases which can lead to mortality. Currently there are a lot of dead and dying trees in our northern lowland areas of Michigan being impacted by spruce budworm followed by bark beetle activity.

Sadly, invasive pest species rolling through our tree resources are also contributing to a large amount of the tree mortality we are seeing. Beech bark disease, oak wilt and emerald ash borer are all currently active across a vast portion of Michigan and are contributing to tree losses in both our forest, recreational and landscape regions.

In an effort to help prevent new exotic species from becoming established and causing additional tree losses, Michigan State University Extension has introduced a new program. This project is an effort to help residents learn about the risks and impacts of invasive forest pests. The “Eyes on the Forest” program links research, outreach and communication activities through MSU’s Department of Entomology and MSU Extension.

Targeting three potential new threats to our forest and urban trees, the program is working to create a network of sentinel trees across the state. The ultimate goal is to recruit trained volunteers who agree to “adopt” an individual tree, and periodically monitor and report on the condition of the tree over time.

If interested in becoming a volunteer or for more information on the program designed to help better protect our states tree resources visit the Eyes on the Forest website or contact:

Russell P. Kidd
Outreach Coordinator
kidd@msu.edu

Dr. Deborah McCullough
Professor, MSU Departments of Entomology and Forestry
mccullo6@msu.edu

For more information on these and other invasive pests and diseases threatening our natural resources, visit the Midwest Invasive Species Information Network.

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