Galloway, N.J. – Stockton’s Galloway campus is adorned with a variety of trees and shrubbery, one of its most eye-catching features - but besides its beauty, a forest also tells a story. Matthew Olson, assistant professor of Environmental Science, began a project over winter break that grew into a winter tree identification guide to better help his Forest Measurements class understand that story.

“I teach Dendrology (the study of trees and their identification) in the fall when deciduous trees (trees that produce leaves that live for a single season) still have living leaves. However, once winter sets in and deciduous leaves have dropped, tree identification in our forests can be challenging,” Olson said. “Additionally, only about half of my students in Forest Measurements have taken Dendrology and the other half may not be familiar with the tree species growing in Stockton’s woods (with or without leaves).”

Olson began the project by listing out the species that he had encountered in Stockton’s woods. Then, he added species that grow nearby but he hadn’t detected in the campus forest (e.g., shagbark hickory). The next step was a search for specimens of each species to take pictures of bark, twigs and whatever else could be used to correctly identify trees in winter, such as acorn caps, cones, dead leaves, etc.

“I also tried to capture variability in the features I was photographing, since most species exhibit variability in their morphology (colors, shapes, and sizes of their parts). Finally, I used several published references and online resources to help with descriptions of species’ morphology. In the next version, I plan to add a dichotomous key to facilitate use of the guide,” Olson said.

This process took little over a month to complete. The guide currently includes descriptions of 27 species of woody plant, 22 trees and five shrubs.

“I intentionally excluded a few of the less common species in this version, mainly due to time constraints. I see this as the first edition of an evolving document. I may also expand the guide to include all, or most, species in southern New Jersey, but that’s more of a long-term vision.”

When asked if any findings were unexpected, Olson reflected, “No real surprises. If anything, I’ve become even more appreciative of the morphological variability within and between the species of the Pine Barrens. I’m also determined to learn more about our native hickory species and the extent to which black birch grows in southern New Jersey. Black birch is considered more of an Appalachian species, but it grows in/around Wharton State Forest in Shamong Township.”

Olson has asked his students to save a copy of the guide to their mobile phone to assist in data collection during outdoor class activities. He also shared this guide with several faculty in the Environmental Sciences program who teach spring classes with an outdoor component and intends to share it with his Ecological Forest Management class in Fall 2021.

“Broadly speaking, correct tree identification is fundamental to appropriately and sustainably manage a forest. My hope is that this guide will not only help students correctly identify trees in our outdoor classes at Stockton, but also enrich their general understanding and appreciation of trees and forests,” Olson concluded.

Reported by Mandee McCullough