On July 4-5, 1999 a derecho (widespread wind storm) resulted in damage to 370,000 acres (out of 1 million total acres) and the loss of 25 million trees in the Boundary Water Canoe Area Wilderness (BWCAW) in northern Minnesota. Explain what you expect

Question

will happen to the forest stand in the BWCAW as a result of this disturbance.

What will be an ideal response?

Answer 1

After a disturbance such as this windstorm (or fire or logging), a forest goes through four stages of succession. The forest first enters the establishment stage, when tree seedlings germinate on the newly cleared forest floor. Due to the loss of old-growth trees, these seedlings have abundant light and little competition for nutrients and water, and quickly grow into saplings. As these saplings grow, competition for light, nutrients, and water intensifies, leading to the next stage of succession. In the thinning stage, the largest trees continue to grow, but the total number of trees declines from several thousand per acre to several hundred, due to intense competition for resources. At the end of the thinning stage, large trees begin to die and leave gaps in the forest canopy. This leads to the transition stage, where seedlings can become established in these gaps. If there are no further disturbances, the forest will finally enter the old-growth stage, which is characterized by a mixture of large old trees and woody debris. Minnesota is a colder climate, so this recovery may take several hundred years.