Conservation of ash diversity: effects of wide-scale insecticide application on genetic structure, recruitment, and regeneration of ash in forests invaded by emerald ash borer

Wide-scale mortality of Fraxinus (ash) by emerald ash borer (Agrilus planipennis, EAB) threatens the genus with regional extirpation, creating the need for strategies to conserve the ash gene pool.  In such an attempt, the Five River MetroParks system near Dayton, OH initiated an ongoing program to protect 600 mature ash trees (F. americana, F. pennsylvanica, F. quadrangulata, and F. profunda) with insecticide.  The goal of our study is to evaluate the effect of this conservation program on genetic diversity and ash population dynamics.  We hypothesize that protecting mature, reproductive ash with insecticides can maintain population structures, genetic diversity, recruitment, and regeneration of ash populations.  We are characterizing the demography of different age cohorts of ash in order to determine the effects of EAB invasion and insecticide treatments on density, survival, reproduction, and genetic diversity of ash populations.  Ultimately, these data will be used to generate an optimized model of ash conservation via selective insecticide treatment that can be used to conserve phenotypic and genetic diversity in other ecosystems invaded by EAB.