1. Does Virginia Creeper grow more quickly when it is attached to a substrate? Does Virginia Creeper prefer to grow on some tree species more than others? Acknowledgments We thank Beth Wilkerson for helping us with GIS data, John Eskew for his assistance in the greenhouse, Pingleton Sawmill Inc. for allowing us to collect bark samples, and DePauw University for funding our project through the Faculty Development Student/Faculty Summer Research Award. Methods We surveyed two areas in the DePauw Nature Park. We also ran experiments in the greenhouse. Vines and Trees: Friends, Foes, or Indifferent? Scott Meyer, Danny Wetli, Vanessa Fox, Bruce Serlin Biology Department, DePauw University Introduction Vines are superabundant in forests at the DePauw Nature Park. Why is this so? Do these vines have some effect on the trees? Do the trees have some sort of an effect on the vines? Vines “love” to grow on trees, but are they partial to some rather than others, or do they like to grow on all trees? We were interested in answering these questions to manage the health of the forests at the Nature Park, as well as to simply understand these vines a bit better. Research questions Do vines prefer to grow on some trees more than others? Do vines prefer to grow on larger trees? Does Virginia Creeper grow more quickly when it is attached to a substrate? We placed popsicle sticks next to the tip of Virginia Creeper plants in the greenhouse.. These plants were already producing holdfasts. We compared the growth rates of vines with sticks vs. vines without sticks. Biology of vines Grape vines grow tendrils that extend and wrap around other plants. Once attached, the tendrils twine to pull themselves closer to the tree. Mature grape vines have large radial trunks that hang freely from the trees, while the extent of the tendrils are up in the canopy. Virginia Creeper uses holdfasts with adhesive pads that fasten themselves directly to the trees. The scope of our research focused more on Virginia Creeper than Grape. In the forest, we… Measured and mapped trees and vines Cored trees and vines Mapped growth of vines Measured humidity and temperature of bark Collected vines to grow in the greenhouse Collected bark from trees Virginia Creeper is growing on 25 percent of trees at QH and QS combined. (We define a tree as ≥ 8.0 cm diameter at breast height.) Virginia Creeper preferred to grow on sassafras, walnut, and cherry. Virginia Creeper avoided growing on sugar maple. Sugar maple was the most abundant tree at QH and QS. Over one-third of all trees was sugar maple. But only 11% of sugar maple trees were colonized by Virginia Creeper. Virginia Creeper that was attached to the sticks grew at a faster rate than the Virginia Creeper that had nothing to attach to. Does Grape prefer to grow on some tree species more than others? Of the five abundant species in the study area, Grape preferentially grew on cherry and walnut, while it avoided sassafras. Does tree diameter have an effect on vine growth? Virginia Creeper preferred to grow on larger diameter of trees. It even followed this trend when on sugar maple, which as seen to the left, does not like to grow on it. The numbers above the columns are the number of trees of that species that were inhabited by Virginia Creeper. The numbers above the columns are the number of trees of that species that were inhabited by Grape. In the greenhouse, we… Planted Virginia Creeper in pots Measured growth of Virginia Creeper Observed attachment and growth of Virginia Creeper in response to popsicle sticks Conclusions Virginia Creeper prefers what it grows on in regards to species of trees, as well as the diameter of the trees. Virginia Creeper grows faster when its holdfasts are attached to a substrate. Grape prefers the species of tree it grows on but it doesn’t seem to care what diameter of tree it grows on. Grape did not have a size dependent distinction for all of the species though there were a few that were partial to larger diameter trees such as dead, elm, and sugar maple. SpeciesNumber of Trees% of Total Cherry18210.7% Elm41024.0% Sassafras684.0% Sugar maple56433.1% Walnut1267.4% Other1518.9% Dead20311.9% Total1704100.0% Tree summary