Timothy Keating, “Phenological Observations in Downer Woods”
Mentor: Mark Schwartz, Geography

The intent of the phenological observations in Downer Woods is to record tree’s changing leaf color as well as the rate at which leaves fall (annually occuring phenophases). Observing these phenophases is helping to determine how environmental factors affect the phenology of trees. Two major species are the focus of these observations: basswood (Tilia americana) and white ash (Fraxinus americana). Other species additionally observed include red and white oak, hophornbeam, and box elder. Trees are grouped in plots of up to four scattered across the 11-acre woods. These observations tend to begin in September and end by early November when all the leaves have fallen. Leaf color is noted on a scale of 800-890 for each type of tree. 800 denotes no change in color, 810 denotes 10%-49% of the leaves have changed, 850 denotes 50%-89% of the leaves have changed, and 890 denotes 90% or more of the leaves have changed. As for leaf loss on the trees, a scale of 900-990 is employed. 900 denotes no loss of leaves, 910 denotes a 10% loss of leaves, 950 denotes a 50% loss of leaves, and 990 denotes a 90% to total loss of leaves. Data is collected three times weekly (Monday, Wednesday, Friday). These observations have been compiled yearly beginning in 2007. They provide a set of data to be utilized in identifying trends in the phenophases of trees, which can prove useful in diagnosing issues including disease and environmental imbalances. A pressing issue involved within this research is the infestation of ash trees by the emerald ash borer beetle. A significant trend in the death of ash trees has been observed in the woods and across the Eastern United States due to this organism. The phenological research done in this project may assist in better understanding how the infestation affects phenophase development in ash trees and may facilitate early diagnosis.