Genetic and ecological behavior of Pyrus calleryana in a Central Hardwood forest

by

Kalli Dunn, Mike Saunders, Michael Jenkins and Keith Woeste

(KD, MS, MJ)Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN (KW)Hardwood Tree Improvement and Regeneration Center, Northern Research Station, USDA Forest Service, West Lafayette, IN, (KD)Corresponding author: 715 State Street, West Lafayette, IN 47907; kfredri@purdue.edu

Abstract – Callery pear, Pyrus calleryana, is a popular ornamental species that has been planted abundantly across the United States since the 1950s. One particularly aggressive invasion exists on NWSC Crane in Crane, Indiana. This invasion dominates the understory several stands within an oak-hickory forest with stem densities exceeding reported density of other aggressive woody understory invasive species such as bush honeysuckle in similar Central Hardwood forest stands. The effects of the presence of Callery pear in the understory could pose a significant impact on the forest community by reducing species diversity and suppressing regeneration of more economically and ecologically valuable tree species. As such, identifying environmental and genetic factors contributing to the success of Callery pear within this invasion represents an important line of research. This study seeks to quantify the rate of spread of the species through the Crane invasion. The study will also investigate effects of Callery pear presence and density on regeneration and species diversity. Genetic assessments will assess what role hybridization has played in success of the species on Crane. Genetic comparisons will be made to other Callery pear invasions in the region to assess genetic distance between isolated invasions. Results from this work will lead to effective management strategies that could slow the spread of this emerging invasive in Central Hardwood forest stands.