The Trials and Tribulations of Grassland Restoration on Government Island
Start Date
3-11-2024 10:20 AM
End Date
3-11-2024 10:29 AM
Abstract
Government Island is a roughly 3.25 square mile island located in the Columbia River northeast of the Portland Airport. Since 2021 Mosaic Ecology has worked with the Port of Portland to rehabilitate a 50-acre restored grassland site that sits just east of the I-205 bridge. The restoration area is a test field for creating future mitigation areas to offset development impacts on nesting bird habitats in nearby areas. Prescribed fire, the most easily recognized grassland management technique, is unavailable due to the constraints of a major freeway and airport.
When Mosaic began managing the site invasive vegetation was beginning to overrun the area, including velvet grass (Holcus lanatus), Canada thistle (Cirsium arvense), and Himalayan blackberry (Rubus armeniacus). Coupled with the increase in invasive vegetation, a lack of disturbance has led to an overall reduction of species diversity, homogenization of vegetative size classes, and dense grass cover, all of which reduce the habitat quality for nesting grassland birds. Through a variety of management activities, including herbicide application and mowing, Mosaic staff has worked to “reset” a 25-acre portion of the restoration area, with the intent to reestablish a more resilient grassland community. This presentation will discuss the many logistical hurdles of large-scale restoration on an island, designing plant communities with invasive species management in mind, and the importance of including human initiated disturbance activities in the persistence of diverse grassland systems in the built environment.
Subjects
Habitat restoration, Land use planning, Plant ecology
Persistent Identifier
https://archives.pdx.edu/ds/psu/41410
Creative Commons License
This work is licensed under a Creative Commons Attribution-Share Alike 4.0 License.
The Trials and Tribulations of Grassland Restoration on Government Island
Government Island is a roughly 3.25 square mile island located in the Columbia River northeast of the Portland Airport. Since 2021 Mosaic Ecology has worked with the Port of Portland to rehabilitate a 50-acre restored grassland site that sits just east of the I-205 bridge. The restoration area is a test field for creating future mitigation areas to offset development impacts on nesting bird habitats in nearby areas. Prescribed fire, the most easily recognized grassland management technique, is unavailable due to the constraints of a major freeway and airport.
When Mosaic began managing the site invasive vegetation was beginning to overrun the area, including velvet grass (Holcus lanatus), Canada thistle (Cirsium arvense), and Himalayan blackberry (Rubus armeniacus). Coupled with the increase in invasive vegetation, a lack of disturbance has led to an overall reduction of species diversity, homogenization of vegetative size classes, and dense grass cover, all of which reduce the habitat quality for nesting grassland birds. Through a variety of management activities, including herbicide application and mowing, Mosaic staff has worked to “reset” a 25-acre portion of the restoration area, with the intent to reestablish a more resilient grassland community. This presentation will discuss the many logistical hurdles of large-scale restoration on an island, designing plant communities with invasive species management in mind, and the importance of including human initiated disturbance activities in the persistence of diverse grassland systems in the built environment.