As an ecologist, Courtney Robichaud, Postdoctoral Fellow with Carleton University, is interested in using science and evidence to conserve our natural world. She recently completed her PhD at the University of Waterloo (Dr. Rebecca Rooney) where she studied invasive Phragmites australis management in freshwater marshes. This included working with a variety of taxa, such vegetation, invertebrates, and birds. She is continuing her work on wetland restoration at Carleton University, where she is studying how to improve decision making in conservation.

Abstract:
Phragmites australis poses a threat to sensitive wetland habitat. However, the removal of large amounts of established vegetation via herbicide may also pose a threat to native biota. In Long Point, a Lake Erie coastal marsh, glyphosate-based herbicide was applied directly over standing water to control hundreds of hectares of P. australis. Despite being a common practice in the US, this was the first time that this approach has been used in Canada. Our work assessed how the marsh ecosystem responded to herbicide-based P. australis control. This included monitoring herbicide residue in the marshes, and how vegetation, macroinvertebrates, and aerial insectivore birds responded after treatment. Herbicide concentrations in soil and water were consistently very low. The reduction in plant biomass following herbicide treatment resulted in changes to the vegetation community and dramatically more Chironomids (non-biting midges) emerging from herbicide-treated areas. These changes resulted in ideal foraging habitat for aerial insectivore birds, with many individuals preferring to forage over the recently treated areas. Our research demonstrates that the large scale removal of P. australis altered the native community dynamics for a few years after treatment, but that these changes appear to be positive. We suggest managers take care to ensure highly-vegetation ‘refuge’ areas remain in treated wetlands, and encourage longer-term monitoring of communities were possible.

свернуть