Local farmers speak of the “million dollar rains” that the area has experienced lately. Dry spells (without rain for several days, or even weeks) are common in northern Michigan throughout the summer months. The usual consequences are that residents manually water their vegetable and flower gardens, or farmers run their irrigation systems.
We often don’t realize how dry spells and droughts affect the forests of our area. Obviously young trees and seedlings with their shallow root systems will struggle to survive hot weather with a lack of moisture. What is less obvious is the effects of dry weather on older, more established forests. Rains of less than inch may help your lawn grass grow (the roots are inches from the surface), but small amounts of rain do little to alleviate dry conditions in the deep rooting zone of trees.
Trees like firs and spruces have much of their roots within 2 feet of the soil surface. They will struggle earlier than the deeper rooted hardwoods, but they will also benefit earlier from rain relief. Hardwoods, however, often have a delayed or accumulating effect of prolonged dry weather. One species that is still suffering from several recent dry summers is our sugar maple. Sugar maple does grow on our sandy soils, but it prefers a richer soil with more moisture. Die-back of branches in the upper crown is a common sight of sugar maple trees. This condition is, in part, caused by two successive dry and hot summers. So the next time you walk in the woods and you see wet trails, along with a healthy hatch of mosquitoes, remember that the trees are making up for two years of lost rains!
Larry Czelusta is the Missaukee and Wexford County Forester. Call or email to tap into his wealth of forest and landscape tree knowledge: 231.839.7193, firstname.lastname@example.org .