Patterns of Woody Encroachment Establishment in Restored Prairies

No Thumbnail Available
Colton, Andrea
Major Professor
Committee Member
Journal Title
Journal ISSN
Volume Title
Research Projects
Organizational Units
Journal Issue
Is Version Of
Symposium on Undergraduate Research and Creative Expression
Iowa State University Conferences and Symposia

The Symposium provides undergraduates from all academic disciplines with an opportunity to share their research with the university community and other guests through conference-style oral presentations. The Symposium represents part of a larger effort of Iowa State University to enhance, support, and celebrate undergraduate research activity.

Though coordinated by the University Honors Program, all undergraduate students are eligible and encouraged to participate in the Symposium. Undergraduates conducting research but not yet ready to present their work are encouraged to attend the Symposium to learn about the presentation process and students not currently involved in research are encouraged to attend the Symposium to learn about the broad range of undergraduate research activities that are taking place at ISU.

The first Symposium was held in April 2007. The 39 students who presented research and their mentors collectively represented all of ISU's Colleges: Agriculture and Life Sciences, Business, Design, Engineering, Human Sciences, Liberal Arts and Sciences, Veterinary Medicine, and the Graduate College. The event has grown to regularly include more than 100 students presenting on topics that span the broad range of disciplines studied at ISU.

Ecology, Evolution and Organismal Biology

Tallgrass prairies, a key feature of Iowa’s landscapes, are susceptible to woody encroachment. When undisturbed, this natural process makes it easy for woody species to invade open prairies and slowly transition them to forested areas. This study tests how herbivory and prairie diversity affect establishment of woody species in an experimental restored prairie within Ames, Iowa. We identified and measured all woody stems >0.5 m within four plots surrounded by fencing to exclude common herbivores (deer and voles) and in four plots without fencing. Each region contained areas with high and low diversity of prairie seedlings. Plots allowing herbivore access have fewer woody stems in both high and low diversity treatments than plots excluding herbivores, likely due to non-discriminant browsing by herbivores. Plots excluding herbivory had higher numbers of establishment in low diversity only and this was dominated by four species: Acer saccharinum, Cornus drummondii, Vitus riparia, and Pyrus calleryana. C. drummondii, V. riparia, and P. calleryana have fruiting seeds, which indicates that the more successful species tend to be frugivore dispersed. Overall, this study shows that areas with a lower diversity of non-woody prairie plants that exclude herbivory provide for higher establishment of invading woody seedlings.