Forest Compositional Changes after a Decade of Emerald Ash Borer

Emerald ash borer is an invasive pest in North American forests. Ecological impacts of ash mortality from emerald ash borer are wide-ranging, including shifts in insect communities and wildlife behavior. Additionally, loss of ash from forests may have important implications regarding plant succession. Surveys of overstory, midstory, and understory trees within forests in northeastern Indiana, Lower Peninsula of Michigan, and northwestern Ohio were conducted to quantify the change in forest composition over a 10 year period. Interpolation of ash dominance illustrated inversion of live and dead ash values between 2007 and 2017. Even though more than 83% of overstory live ash basal area was lost across the study area, green ash was the most abundant midstory and understory species representing regeneration. Additionally, loss of ash from many of the sites resulted in compositional changes that were greater than merely the subtraction of ash. Due to the relatively large number of forest types with which ash species are associated, loss of ash will have broad ecological consequences, including on community composition.