BUFFALO, NY– The U.S. Army Corps of Engineers’ Buffalo and Detroit Districts, along with Engineer Research and Development Center (ERDC), and Ecology and Environment, Inc. completed a - five year project from 2014 to 2019 designed to manage invasive species across four riverine islands in the Menominee River.
The goal of the Menominee River Area of Concern (AOC) Aquatic Plant Control for Rookery Habitat Project was to reduce the abundance of invasive species, so native plant communities can thrive in the future, and protect the rookery.
“Protection of the rookery sites are so important to wildlife conservation because a large number of breeding individuals occurs in a single place,” said Timothy Noon, Army Corps of Engineers, Buffalo District’s project manager. “If a rookery gets abandoned due to any type of disturbance then a loss of productivity for one or more season can occur.”
The islands used were Little Blueberry Island, Blueberry Island, Boom Island, and Strawberry Island, totaling 17-acres.
The project completed several activities: invasive plant species controls; restoration planting with native trees, shrubs and seeds; vegetation monitoring; bird surveys; and stakeholder coordination.
“A specific concern for an active rookery or potential rookery habitat is that the thin, high-density stems of the invasive shrub are not strong enough to support heron and egret nests,” Noon said.
All four islands had mechanical and chemical treatments for invasive species completed starting in 2015. The most abundant invasive species on the project islands included common buckthorn, glossy buckthorn, and exotic bush honeysuckles.
“We’re very pleased with the results of the treatments completed during the Project,” said Noon. “It reduced the extent and relative abundance of invasive species across the four islands by approximately 90%. Mature invasive plants were mostly eradicated.”
After the initial treatment of invasive species, project restoration plantings began in the fall of 2016 and summer and fall of 2017 and 2018. The project plantings encompassed trees, shrubs, and seed mixes.
“Species and planting locations were selected to promote a complex vegetation structure, and low and high canopy shade in disturbed areas of the islands,” said Noon.
These project restoration plantings proved successful, native and acceptable plant species now dominate the project’s four islands.
Even with the success of the treatments and restoration plantings, some maintenance will be needed in the future in order to control these invasive plants. Each year the invasive seedling germination had a response on all four island. This resilience shows the viability of the invasive seed bank and the importance of continued efforts to control these invasive species.
Bird surveys were also conducted each year during spring and fall migrations, and during the breeding seasons. One-hundred and nineteen bird species were recorded during these seasons within the project area. The data collected from monitoring the birds remained relatively the same throughout the four years.
The final phase of the project was stakeholder coordination.
“An important part of our work in 2018 was to spread awareness and familiarity of the project, and make connections with organizations, groups, agencies, and people that find interest in continuing stewardship of the islands past completion of the project,” said Noon.
Project partners included Wisconsin Department of Natural Resources, Michigan Department of Natural Resources, the AOC Technical Advisory Committee, North East Wisconsin Hydro, LLC and the citizens’ advisory committee, and the Wild Rivers Invasive Species Coalition.
The project has been successful in establishing future invasive species control and monitoring activities with the Wisconsin River Invasive Species Coalition (WRISC). Through coordinated stakeholder engagement, a plan is in place between WRISC and the island landowners to pursue stewardship and monitoring into the future as funding allows.
“The Project brought to light the ecological importance of the islands within the lower Menominee River and was a catalyst for increased local and regional knowledge and interest in the natural resources that the islands represent,” said Noon.