DOES EMERALD ASH BORER RELATED WHITE ASH MORTALITY DRIVE NITROGEN CYCLING AND CHANGES IN SOIL ORGANIC CARBON?

Emerald ash borer (Agrilus planipennis Fairmaire - EAB) is a phloem boring invasive insect first identified in 2002 in southeast Michigan (USA). As of 2017, EAB is established in at least 28 states across the US and two Canadian provinces. Estimates of white ash (Fraxinus americana) mortality in some forested areas exceeds 90%, and over 25 million ash trees in Michigan have already been killed by the species; however, not much is known about changes in nitrogen cycling and organic carbon in the shallow layers of soil in EAB impacted forests. Differences in the timing of invasion, and the timing of morality across different sites makes some data difficult to capture, but through soil sampling at pre-leaf out, peak season, and post senescence, a characterization of differences in nitrogen cycling and carbon loss across living (mortality <15%), mixed (mortality between 15% and 40%), and dead (mortality >40%) sites can be drawn. Total soil organic carbon levels were measured by loss on ignition testing, and deionized water leachates were used to estimate bioavailable nitrogen. Preliminary carbon loss data suggests there is a significant difference between median organic carbon between live and dead sites across the growing season. Studying the effects of nutrient cycling and differences of carbon levels provides implications on regrowth, vegetation dynamics, and effects of runoff across sampled sites.