Deer Herbivory at the Nature Park:  A Cause for Concern?


Shayla Williamson and Genevieve Espinoza were
two students in Dana's Dudle's class who helped put up the deer
exclosures. We will continue monitoring
the vegetation in the exclosures and in adjacent
un-exclosed areas to assess the effects of deer herbivory.

Dana Dudle and Vanessa Fox

Class project for Conservation Biology, BIO 345, Ecology, BIO 342, and Biostatistics, BIO 375

Are white-tailed deer affecting vegetation at DePauw’s Nature Park?  Deer populations have been increasing throughout the eastern United States during the last 100 years.  Over-browsing by deer causes changes in local plant communities.  Deer browse on the stem tips of young trees, causing damage or mortality of the regenerating layer (Tilghman 1989, Liang and Seagle 2002).  Preferential browsing on seedlings of some tree species more than others can dramatically change the pathway of succession of the forests over the course of time (Kittredge and Ashton 1995, Liang and Seagle 2002, Horsley et al. 2003, Carter and Frederickson 2007).  Some herbaceous plant species such as Trillium may be driven to local extinction by deer over-browsing (Augustine and Frelich 1998).  Bird communities are also affected, with lower densities of birds occurring in heavily browsed forests in comparison to areas protected from deer (McShea and Rappole 2000).

Deer hunting can counteract these negative effects on forest communities.  Deer hunting is prohibited in DePauw’s Nature Park, but the Nature Park Steering Committee has been discussing the idea of allowing a limited hunt at the Nature Park to reduce the deer population.  We conducted a project to assess the effects of deer browsing on vegetation in the Nature Park.  Our goal was to provide information about the effects of deer for the Steering Committee to help their decision-making process. 

We assessed effects of deer browsing by comparing the growth of plants in exclosures (fenced-off areas) and control areas (open, unfenced areas).  Exclosures and controls were set up in a riparian forest along the Creekside Trail during spring 2006.  Another set of exclosures and controls were set up in lowland forest at Quarry South in the Nature Park during spring 2008. We collected data on the growth of plants in the controls and exclosures during fall 2007 and spring 2008, about two years after the exclosures were set up. 

Click here for more information about deer at the Nature Park