Impacts of White-Tailed Deer on Red Trillium ('Trillium recurvatum'): Defining a Threshold for Deer Browsing Pressure at the Indiana Dunes National Lakeshore.

摘要

Overabundant white-tailed deer (Odocoileus virginianus) have been a concern for land managers in eastern North America because of their impacts on native forest ecosystems. Managers have sought native plant species to serve as phytoindicators of deer impacts to supplement deer surveys. We analyzed experimental data about red trillium (Trillium recurvatum), large flowered trillium (T. grandiflorum), nodding trillium (T. cernuum), and declined trillium (T. flexipes) growth in paired exclosure (fenced) plots and control (unfenced) plots from 2002 to 2010 at the Indiana Dunes National Lakeshore. The latter two species lacked replication, so statistical analysis was not possible. All red trillium plants were surveyed for height-to-leaf, effects of browsing, and presence of flowers.