Student Spotlight - Morgan Parkes

Deer Browsing on Logged, Girdled Plots
by Morgan Parkes
Fall 2006 

During May, June, and July, I did research for my senior thesis in environmental policy for Barnard College on the north slope of Black Rock Mountain.  Dr. William Schuster, the Black Rock Forest Director, and Dr. Peter Bower, a professor and my academic advisor at Barnard, sponsored my work this summer.

I am studying the ecosystem effects of logging and girdling oak trees, using the study plots created for Black Rock’s “Future of Oak Forests” research project [Ed. Note: See “What Will Happen to Our Forests if the Oaks Die,” Spring 2006].  Girdling simulates death by pathogens, such as chestnut blight, Dutch elm disease, or sudden oak death, since the trees remain standing on the plot as they die.

I want to know how both these processes will affect deer browse within the Forest.  The forest understory and the future of northeastern forests are threatened by deer browse because, with deer overpopulation, many seedlings are consumed before they can grow into healthy, mature trees.

I hypothesized that deer browse would be greatest on the logged plot, less on the girdled plot, and least on the control plot (the plots that have been left as is).  The logged plot now has the most light, allowing for more seedling regeneration, while the control plot has the least amount of light coming in through the forest canopy, and the girdled plot is somewhere in between the two.  Because the logged plot will have the most seedling regeneration, I believe it will become a “hot spot,” so to speak, for deer.

I began collecting data in late July on the three plots.  Each plot has a section that is fenced to enclose it so that deer cannot get in.  This section of the plot serves as another control.  I sampled seedlings in 1-m2 plots along a transect in the central subplots of the control, logged, and girdled plots on both the fenced and unfenced sides of each.  In all, I sampled 20 plots: I counted the seedlings, determined their species and age, and assessed browse intensity (how many times a plant looks as if it has been browsed).

I am now analyzing my data, and have found that the most browse is on the girdled plot.  I suspect that this may be because the effects of logging include altered pathways for the deer.  It is much harder for a deer to maneuver through the bramble and fallen logs of the logged plot than on the clean slopes of the girdled plot.

I hope to continue my researchthroughout the coming year, looking at the impact of deer browse in the sample plots over the fall and winter, and will also make trips to Black Rock Forest with my class on Field Methods taught by Dr. Bower.

Morgan Parkes is a Barnard senior with a dual major in environmental policy and economics.