Does removing Oriental bittersweet affect tree growth?

Invasive, non-native species can substantially influence an ecosystem, affecting overall biodiversity especially the abundance of native species. Many invasive species possess an adaptation that allows it to grow and outrank other species present, such as our focus for this project, Oriental bittersweet (Celastrus orbiculatus). Our project follows up on previous studies done from 2013-2016 in the experimental forest behind Westfield State University where students and faculty treated the spread of bittersweet growing on trees. The main goal of this project was to examine tree cores and assess tree ring width from a portion of the recently treated trees. We also wanted to evaluate the health and growth of trees after the removal. We collected tree cores using an increment borer, which can determine age, and the previous and current effects of the bittersweet. We took a total of 14 cores from various maple, red oak, cottonwood, and American elm trees. Once the cores were glued down they were measured by the distance between each ring for each growing season. The measurements between each tree ring showed a noticeable difference between each growing season throughout the decades. In the years following the bittersweet removal, the variation in the tree-ring width had decreased. We can speculate bittersweet roots are still inhabiting underneath the experimental trees which are stealing the nutrients necessary to grow. Data between the years 2010-2014 shows that there was no significant effect on the tree sample’s growth pattern.