Re-evaluating the ecological role of a keystone species at the urban-wildland interface
PhD: University of Colorado Boulder, 2015.
Prairie dogs are receiving increased attention from landscape restoration managers as a result of intensified interactions at the urban-wildlife interface. While prairie dogs are regarded as a keystone species in natural grasslands due to their effects on ecosystem function and biodiversity, recent studies at the urban-wildland interface have linked the presence of prairie dogs to unexpected plant compositional changes and the creation of novel plant communities. Due to the link between plant community composition, ecosystem structure, and function, the development of novel communities on prairie dog colonies at the urban-wildland interface suggests the creation of a system highly resilient to restoration efforts with altered ecosystem services. To this aim, my dissertation examines prairie dog colony restoration at the urban-wildland interface by observing changes to plant communities and species following the removal of prairie dogs due to plague epizootics and management intervention. I demonstrate that plague extirpations will not restore plant communities to historical compositions, but rather allow for a potential proliferation of introduced winter active species and exotic forbs. Furthermore, I determine that three years of prairie dog removal will not return plant communities, groups, or vegetation diversity to the levels equivalent to those found on uncolonized areas, and will transition the restored communities to alternative compositions. I also examine the relationship between prairie dogs at the urban-wildland interface and two ecosystem services: wind erosion mitigation and plant productivity, which are both regulated by prairie dogs in a more natural landscape. My analyses showed nearly ten times the amount of wind erosion emanating from prairie dog colonies at the urban-wildland interface compared to adjacent uncolonized areas, as well as lower forage biomass on colonies than uncolonized grasslands in the region. This research shows that prairie dogs at the urban-wildland interface are operating outside of their historical context, and have the ability to dramatically impact grasslands ranging from plant community compositions to higher level ecosystem services. The ecological role of the prairie dog has changed at the urban-wildland interface, and understanding these changes will be critical for future sustainable management of these valuable grassland areas.