POSTER PRESENTER: http://tinyurl.com/2024WSC-Rademacher CO-AUTHOR: Daniel Tix, MNL TITLE: Adaptive management of invasive hybrid cattails (Typha x glauca) at the Minnesota Landscape Arboretum ABSTRACT: Native vegetation is often displaced by dense stands of invasive hybrid cattail (Typha x glauca) in Midwestern wetlands. Hybrid cattails have invaded multiple wetlands at the University of Minnesota Landscape Arboretum, including the area around Green Heron Pond. The shallow open-water pond is part of a wetland complex that includes the surrounding cattail marsh, shrub swamp, and sedge meadow communities. Surveys prior to treatment indicated approximately 90% of the marsh was covered in hybrid cattail from shrub line to the water’s edge. In 2020, we began treatment with a broadcast herbicide application using aquatic glyphosate from a Marsh Master (a tracked amphibious vehicle). In 2021, we completed a follow-up treatment with an agricultural drone sprayer, and we have since completed spot treatments using backpack sprayers. Following two years of herbicide treatments, we planted more than 750 plugs of emergent marsh species in the cattail thatch. A meander survey in the fall of 2022 showed a reduction to approximately 25% cover of hybrid cattail and an increase in native plant diversity and cover. With the use of different herbicide application techniques, we have found advantages and disadvantages to each that will inform future management strategies at this site and other wetlands. We also experienced several challenges that have impacted management or project results, including ongoing drought, altered hydrology, site access, and budget. Despite these obstacles, our project is showing promising results from intensive herbicide applications with continued follow-up treatments as the cattail thatch slowly degrades and allows for more native plant recolonization. BIO: Sarah Rademacher is the wetlands horticulturist at the University of Minnesota Landscape Arboretum, where she manages the habitat restoration projects in several of the wetlands at the Arboretum. She received her bachelor’s degree in forest restoration and management at UW-Stevens Point and her master’s degree in forestry at Purdue University.