Background/Question/Methods Rocky Mountain National Park is home to complex native plant and animal communities that have developed since the last ice age. The ecological balance of native plant communities located within the montane and lower subalpine life zones are currently being threatened by the highly invasive, non-native, annual cheatgrass.  Nitrogen deposition, elk herbivory, climate change, and human-caused disturbances have likely increased the occurrence and spread of cheatgrass into disturbed and undisturbed lands. Since cheatgrass infestations within the park occur in variable site conditions (i.e. differing plant communities, aspects, elevations, etc.), this project aims to develop specific treatment and restoration strategies for a variety of site conditions.
Results/Conclusions In 1987, cheatgrass rarely inhabited sites above 2,438 m in Rocky Mountain National Park. In 2008, data indicated that 137 of 153 known infested hectares occur between 2,438 m and 2,822 m. In 2008, cheatgrass sites were characterized and six Circular Nested Plots (CNP’s) were installed to study the effects of imazapic treatments on target and non-target plant species. In addition, six reference CNP’s were installed in adjacent non-infested sites for comparison. Rocky Mountain National Park and the Natural Resource Conservation Service Plant Material Center in Meeker, Colorado are cooperating to increase local genotypes of early, mid, and late seral native plant species to outcompete cheatgrass and other invasive non-natives in a variety of site conditions. Preliminary conclusions and management implications will be presented for high elevation cheatgrass infestations.