Spotted knapweed plant management and restoration of native grassland in Waterton Lakes National Park, Alberta

Abstract

The province of Alberta is known for its prairies, which are ecosystems dominated by temperate grasslands. These grasslands contribute to flora and fauna biodiversity, but are the most endangered ecosystems in the region, due to the invasion of non-native species. Waterton Lakes National Park in the Canadian prairies is the only Canadian national park that preserves these grasslands under the foothills parkland ecoregion, which is an environmentally sensitive site characterized by rough fescue. It is mostly threatened by spotted knapweed (Centaurea stoebe), a perennial plant that spreads from disturbed anthropogenic sites. The park’s vegetation restoration team has applied two main types of invasive plant management techniques over the years, which are mechanical and chemical treatments. This research study attempts to identify effective ways for restoration of native plant communities in Waterton Lakes National Park, Alberta, by comparing the effective use of chemical and mechanical techniques from 2014 to 2017. Our results show that chemical herbicide was found to be economically efficient (with lesser number of persons) for higher abundance of spotted knapweed infestation in larger areas, whereas the mechanical treatment is ecologically efficient (little impact on native plant communities) for the control of spotted knapweed infestations in the flowering stage in smaller areas. We recommend an integrated management plan for control of invasive species that combines the effective use of chemical and mechanical techniques. The integrated management plan will help the park management in conservation and restoration of the fescue grasslands in the foothills parkland ecoregion, which are important for protecting the rare and endangered flora and fauna.