NCSU’s Steve Frank Lab has studied the effects of urban warming and other factors on tree pests and tree health for several years. Their main take: ” When do you have too much impervious surface? Adam Dale and Elsa Youngsteadt created a benchmark to indicate when there’s too much impervious surface for red maple (Acer rubrum) to thrive. They knew based on research results studying red maple in Raleigh, NC that trees will be in good or excellent condition when impervious surfaces are less than 32% within about 80 feet of the tree. Once impervious cover hit one-third to two thirds, trees were in fair condition. Above two-thirds impervious surfaces and trees were in poor condition. To make it easy for landscapers, designers and urban foresters in the field, they developed a “Pace to Plant” technique that can be used (see page 185 in the article below). By pacing transects of the planting area and counting the number of steps that fall on impervious surfaces, anyone can get a read on where red maples will thrive.
Arboriculture & Urban Forestry
NewTerrain August 15 2016