Mammalian herbivores are a significant driver of plant species composition in tallgrass prairie. Despite their demonstrated importance and ubiquity in prairies, considerable uncertainty remains concerning the interactive effects of mammalian herbivores in prairie ecosystems. This project will use an existing long-term prairie restoration with sites of different ages to examine the interactive effects of three dominant herbivore species -- deer, rabbits, and voles -- on plant community composition and rates of soil carbon and nutrient cycling. Herbivore exclosures will be established in prairies of different ages to determine how the influence of herbivory changes through time.
This work will improve our understanding of the role of herbivory in restored prairie ecosystems. Prairie restorations rarely take into account the importance of herbivores, thus the project has important implications for the management and restoration of grassland ecosystems. This research will integrate research, outreach, and education with undergraduate students, K-12 students, and the community. The project will recruit students from underrepresented groups for summer research opportunities for undergraduates. In addition, the proximity of the project to the college campus provides opportunities for both K-12 and community education. Finally, the project will enhance undergraduate education in ecology through the development of new inquiry-based laboratory activities.
This project has established a long-term experiment investigating the roles of mammalian herbivores in restored tallgrass prairies of in the Carleton College Cowling Arboretum. Herbivores are a major driver of energy flow and nutrient cycling in ecosystems. Herbivores can impact plant growth and species diversity and have direct and indirect impacts on the cycling of nutrients in ecosystems. In grassland ecosystems in particular, herbivores have a significant impact on plant community composition and ecosystem processes. North American tallgrass prairie was once the dominant ecosystem type of the Great Plains, but little of this original ecosystem remains. However, recent conservation efforts are leading to the restoration of tallgrass prairie throughout its former range. Restored prairies contain a novel assemblage of both plant and animal species and provide a unique opportunity to investigate the role of herbivores in influencing community structure and ecosystem processes. This study was established to determine the relative importance of different herbivore species in restored prairie, the changes in the importance of herbivore impacts as restored prairie ecosystems develop over time, and the interactive effects of multiple herbivore species on community composition and ecosystem processes. To date, the project has resulted in two peer-reviewed publications (both with undergraduate co-authors), three conference presentations, two presentations at the local middle school, and presentations and newspaper articles at Carleton College. The findings of this research have advanced understanding of the rates of soil carbon and nitrogen accumulation through the development of restored prairie ecosystems over time and on the causes and consequences of selective herbivory by deer in prairie communities. This project is ongoing and will continue to explore the role of herbivores in restored prairies. This project has had a significant impact on the training and mentoring of undergraduate students and outreach opportunities in the local community. To date, the project has involved 15 undergraduate research assistants. Three of these students have gone on to graduate school in ecology and eight are continuing to work in research positions in the field. The project has provided research opportunities to students in ecology classes at Carleton College through the development of a laboratory exercise that takes advantage of the experiment and has increased the visibility and understanding of ecological research on campus. The project has also involved eight Hispanic middle school students in field and laboratory research over two years by partnering with a local program designed to increase college access for underrepresented groups.
