Are Rotational Grazing Practices Impacting Native Vertebrate Diversity in Pennsylvania Streams?

Angela McCarty and Dr. Carlos Iudica, Department of Biology, Susquehanna University, 514 University Avenue, Selinsgrove, PA 17870

Adams County, located in South Central Pennsylvania, is an area with high agricultural activity, specifically raising livestock, often in pastures that contain natural waterways. Studies suggest that by removing livestock from these waterways greatly improve stream quality which may benefit vertebrates that depend on these water sources. To further investigate this, over the course of six months (October 2020-March 2021) four sites were surveyed to look at the impact of the presence of cows on species diversity in a local waterway. Of these four sites, one is outside of pastured area, two are rotationally grazed, and one is grazed year-round. Each location had two trail cameras, with one pointing upstream and the other down, images and batteries are monitored biweekly. In addition, each site had a minnow trap half submerged, to allow semi-aquatic species to receive oxygen while inside and is checked every other day. Data recorded in spreadsheets will be presented using ArcGIS, and species richness calculated using the equation D = s √N. Preliminary results already suggest that site four, a rotationally grazed piece of pasture of about 4 acres, may have the highest species diversity as data currently shows it having the most terrestrial and aquatic species. The species that appear to be most abundant are red fox (Vulpes vulpes) for terrestrial species and American bull frog tadpoles (Lithobates catesbeianus) for aquatic. This suggests that rotationally grazed sites may have higher vertebrate diversity than those grazed year-round or never grazed. I plan to analyze these results within the framework of Osman’s intermediate disturbance hypothesis.  

Additional Abstract Information

Presenter: Angela McCarty

Institution: Susquehanna University

Type: Poster

Subject: Ecology

Status: Approved

Time and Location

Session: Poster 5
Date/Time: Tue 12:30pm-1:30pm
Session Number: 4092