The impacts of invasive plants and insects on native ecosystems has been well documented. Once established,and depending on their impact, some invasive species may persist, thus creating an entirely different ecosystem than that before the introduction occurred. These “novel ecosystems” are likely to become more and more common as additional destructive non-native species are introduced.
Our lab is heavily invested in examining the ecological impacts of the emerald ash borer (EAB) on forests in the region. EAB has now spread to 20 states and 2 Canadian provinces, but was originally introduced in suburban Detroit, making Michigan an important fore-bearer of ecological impacts of EAB in other states.
Our lab has completed important research describing the potential of ash to persist in the presence of EAB by examining the structure and dynamics of ash regeneration across the landscape. Despite widespread and initial predictions that ash will not persist in the presence of EAB, research in our lab on post-EAB ash fruiting and recruitment dynamics and re-sprouting is beginning to suggest that ash may be able to maintain itself in the presence of EAB, albeit in smaller stature and lower abundance. Our lab has shown that green ash, in particular, has potential for persistence because of its ability to sprout vigorously after EAB-caused mortality and the ability of the sprout to quickly produce viable seed. We have documented similar trends in southeastern Michigan with white ash and blue ash. Our lab is developing new post-EAB studies of black ash, which was less abundant in southeastern Michigan prior to EAB and is most favored by the invasive insect. A major emphasis of this collection of studies is that although all ash species are susceptible to EAB, not all respond similarly.
A different facet of our work on emerald ash borer is to examine the impact of EAB biocontrol efforts in Lower Michigan. In 2007, USDA’s Animal and Plant Health Inspection Service (APHIS) began to release three parasitoid wasp species from China to control populations of EAB. With confirmed establishment of these natural enemies of EAB, our lab has been critical in collecting baseline information on ash health and regeneration (specifically, monitoring the growth, density, and survival of seedlings, saplings, stump sprouts, some larger survivors, and seed production/germination) at EAB-biocontrol release and control plots in order to determine the long-term impact of parasitoids on EAB and subsequently the ash genera.
Related funding at Wayne State:
USDA Animal and Plant Health Inspection Service – (Co-PI with L. Bauer and T. Poland). 2012 – 2017. Evaluating the impact of emerald ash borer and biological control on ash mortality, health, and recovery in southeastern Michigan. $25,000.
USDA Animal and Plant Health Inspection Service – (Co-PI with L. Bauer, T. Poland, and T. Petrice). 2019 – 2020. Determining the impacts of EAB biological control on ash health and regeneration. $25,000.
Related publications at Wayne State:
Kashian, D.M., L.S. Bauer, B.A. Spei, J.J. Duan, and J.R. Gould. Potential impacts of emerald ash borer biocontrol on ash health and recovery in southeastern Michigan. Forests 9: 296.
Spei, B.A., and D.M. Kashian. 2017. Potential for persistence of blue ash in the presence of emerald ash borer in southeastern Michigan. Forest Ecology and Management 392: 137-143.
Costanza, K.K.L., W.H. Livingston, D.M. Kashian, R.A. Slesak, J.C. Tardif, J.P. Dech, A.K. Diamond, J.J. Daigle, D.J. Ranco, N.W. Siegert, J. Neptune, L. Benedict, S. Fraver, and M. Reinikainen 2017. The precarious state of a cultural keystone species: Biological and tribal assessments of the role and future of black ash. Journal of Forestry 115: 435-446.
Kashian, D.M., 2016. Sprouting and seed production may promote persistence of green ash in the presence of the emerald ash borer. Ecosphere 7: e01332.
Kashian, D.M., and J.A. Witter. Assessing the potential for ash canopy tree replacement via current regeneration following emerald ash borer-caused mortality on southeastern Michigan landscapes. Forest Ecology and Management 261: 480-488.
landscape. Despite widespread and initial predictions that ash will not persist in the presence of EAB, research in our lab on post-EAB ash fruiting and recruitment dynamics and re-sprouting is beginning to suggest that ash may be able to maintain itself in the presence of EAB, albeit in smaller stature and lower abundance. Our lab has shown that green ash, in particular, has potential for persistence because of its ability to 
sprout vigorously after EAB-caused mortality and the ability of the sprout to quickly produce viable seed. We have documented similar trends in southeastern Michigan with white ash and blue ash. Our lab is developing new post-EAB studies of black ash, which was less abundant in southeastern Michigan prior to EAB and is most favored by the invasive insect. A major emphasis of this collection of studies is that although all ash species are susceptible to EAB, not all respond similarly.