Estimating Invading Callery Pear (Pyrus calleryana) Age and Flowering Probability in an Indiana Managed Prairie

Abstract

Callery pear (Pyrus calleryana Decne.) is an invasive species in North America originating from Asia. As an ornamental tree, Callery pear has been widely planted throughout much of the United States and has subsequently spread into natural areas. Callery pear individuals that had naturally colonized a managed prairie in Indiana were collected. Tree height and root collar diameter were measured and the presence of flower buds was identified. After harvesting the trees, age was measured as ring counts. Height, root collar diameter, and age were all significantly greater for flowering individuals compared to nonflowering trees. Root collar diameter was the only independent variable that resulted in a significant linear model for predicting tree age. Additionally, root collar diameter effectively predicted the likelihood of flowering in Callery pear, with a tree root collar diameter of 45.6 mm predicting a 50% chance of flowering. Age was an ineffective independent variable in predicting flowering potential in Callery pear. Root collar diameter can provide a rapid assessment of invasion age, as well as predicting flowering potential outside of the growing season. Management focus can be on larger individuals.