Ash (Fraxinus spp.) mortality, regeneration, and seed bank dynamics in mixed hardwood forests following invasion by emerald ash borer (Agrilus planipennis)

Review of Ecosystem Level Impacts of Emerald Ash Borer on Black Ash Wetlands: What Does the Future Hold?

“…As a result, black ash has all the same cues for the female borer but none of the resistance, leading to higher initial decline rates. Across the same gradient of stands, all ash mortality was greater than 99% by 2009 (Figure 4; [27]). In the years shortly after EAB invasion in lower Michigan, and during the decline of black ash, there were numerous black ash seedlings and saplings in the understory, but by 2009 few to no ash seedlings germinated and the seed bank was barren of viable ash seeds [27,28].…”

“…Early work evaluating plant response to EAB was associated with a post-invasion study in southeastern Michigan that included transects and stands across ash cover types with moisture regimes from xeric to mesic to hydric, with those hydric stands dominated by black ash [9,27]. The transects were established in 2004 and emanated up to 45 km from the epicenter of EAB invasion.…”

Progress and Challenges of Protecting North American Ash Trees from the Emerald Ash Borer Using Biological Control

“…The EAB invasion of forests in southeast Michigan, during the 1990s, resulted in nearly 100% mortality of overstory ash trees by 2010 [29,105]. The potential for recovery of the ash canopy was assessed in this region from 2007 to 2009, and abundant regeneration of smaller height class ash trees, mainly F. americana and F. pennsylvanica, were found.…”

“…The potential for recovery of the ash canopy was assessed in this region from 2007 to 2009, and abundant regeneration of smaller height class ash trees, mainly F. americana and F. pennsylvanica, were found. However, young 1-2 year ash seedlings were much less common, and the lack of new seedlings was traced to a depleted seed bank, as few or no nearby mature ash trees existed to provide seed [29,105]. However, the results of a more recent study of regenerating F. pennsylvanica in this region reported abundant seed production on surviving mature ash trees during mast years, as well as on sexually mature small ash trees and basal sprouts regenerating from top-killed trees, suggesting a significant, though greatly reduced, pool of ash trees in this region [106].…”

Responses of Ground-Dwelling Invertebrates to Gap Formation and Accumulation of Woody Debris from Invasive Species, Wind, and Salvage Logging

“…in eastern North America since its accidental introduction from southeast Asia [85]. Ash tree mortality causes widespread, nearly simultaneous formation of canopy gaps in forests [86,87], owing to the low resistance of North American ash species to EAB [88]. The speed, synchrony, and specificity of ash mortality differs from gap-phase dynamics caused by other forest insects.…”