Garry oak ecosystems restoration (Fort Rodd Hill National Historic Site)
Project lead: Parks Canada
Key partners: (see list below)
Location: Fort Rodd Hill National Historic Site, Vancouver Island, British Columbia
Natural region: (not applicable; only applies to National Parks)
Ecozone: Pacific Maritime
Timeframe: 2001 to present
Project size: Garry oak ecosystems comprise approximately 11 ha of the site.
Project overview - Natural and cultural heritage values - Defining the problem - Goals and objectives - Project activities - Monitoring - Lessons learned - What’s next? - For more information - Contacts - Key partners
Parks Canada led the restoration of Garry oak ecosystems at Fort Rodd Hill National Historic Site. The project focused on removing and controlling invasive plants that threatened the rare and sensitive native species associated with Garry oak meadows and associated ecosystems. Some of the rare plants were protected from grazing of hyperabundant deer and rabbits by enclosing a 1.3 hectare area within a fence. Hand-collected seeds from the site were grown in a nursery and resulted in several thousand native plants to be planted within the fenced area. Parks Canada is engaging visitors to Fort Rodd Hill through new interpretive media, as well as through interpretive and volunteer programs.
The actions undertaken by the Parks Canada restoration team demonstrate the best practice approach described in Principles and guidelines for ecological restoration in canada’s protected natural areas. The process of ecological restoration, as described by this approach, adheres to three guiding principles. Restoration should be:
- effective in restoring and maintaining ecological integrity,
- efficient in using practical and economic methods to achieve functional success, and
- engaging through implementing inclusive processes and by recognizing and embracing interrelationships between culture and nature.
Natural and cultural heritage values
Fort Rodd Hill National Historic Site is a coast artillery fort built in the late 1890s to defend the city of Victoria and the Esquimalt Naval Base. The site is owned and managed by Parks Canada, and includes three gun batteries, underground magazines, command posts, guardhouses, barracks and searchlight emplacements.
The site also protects one of the few remaining examples of Garry oak ecosystems in Canada. Garry oak ecosystems have a very limited range in Canada and are considered imperilled, with less than 5% remaining in a near natural condition. They are high in biodiversity and provide habitat for many species at risk. For example, Fort Rodd Hill is home to at least seven plant species considered at risk in British Columbia, two of which are at risk of extinction in Canada, deltoid balsamroot (Balsamorhiza deltoidea) and Macoun’s meadowfoam (Limnanthes macounii). Garry Oak ecosystems range from shady woodlands to open meadows with scattered trees, and include rocky outcrops. Their meadows are particularly breathtaking in spring with showy wildflowers.
Defining the problem
In the past, wildfires and fire management by Aboriginal peoples helped maintain the open character of Garry oak meadows and associated ecosystems. In recent times, fires have been suppressed, creating ideal conditions for establishment of trees and shrubs that are more fire sensitive or faster growing, such as Douglas fir trees. Without fire, many of these areas were naturally maturing into a different ecosystem – in this case an ecosystem dominated by Douglas fir. This was problematic because Douglas fir grows faster and taller than Garry oaks, which cannot tolerate shade.
In addition, increasing development in areas where Garry oak occurs has led to the fragmentation and isolation of “islands” of habitat. As a result, these ecosystems have become more vulnerable to invasion by alien species such as scotch broom (Cytisus scoparius) and spurge-laurel (Daphne laureola), which gradually out-compete and replace the native species. These alien species have not been kept in check by fire, predators, or diseases.
Over-grazing by hyperabundant deer and rabbits has also threatened native species, such as the endangered deltoid balsamroot.
Goals and objectives
The restoration goals for Fort Rodd Hill were to conserve species at risk, restore natural processes, enrich native biodiversity, and have a mosaic of natural habitats such as coastal Douglas fir ecosystems, Garry oak woodlands, meadows, vernal pools and rocky outcrops. The main focus was the removal and ongoing control of invasive species, and protection and enhancement of the rare and sensitive plant species on the site. Grazing by hyperabundant deer also needed to be controlled to ensure the success of the project. In addition, native species of rare plants were grown from seed collected on-site and planted in a fenced area. Finally, tonnes of non-native, invasive shrubs and trees needed to be removed and their re-growth controlled.
Because Fort Rodd Hill is a National Historic Site, ecological restoration needed to be integrated with the program for cultural heritage resource protection and presentation at the site. Restoring Garry oak ecosystems would enhance the cultural aspects of the site by opening up the canopy to reveal historical view lines that had become overgrown with invasive species of shrubs and trees.
An Environmental Assessment (EA) was conducted for the construction of the two restoration exclosures (fenced areas) and other specific work related to the restoration. An archaeological assessment was also conducted prior to beginning the restoration work to ensure protection of the site’s cultural and historical resources.
To restore the Garry oak ecosystems, ecological processes were mimicked through the removal of Douglas fir trees in order to imitate the effects of fire. By the summer of 2004, about 12.5 tonnes of invasive plant species had also been removed. These shrubs and trees had been encroaching on and displacing native plants and disrupting ecosystem processes.
A 1.3 hectare site within a priority Garry oak stand was fenced to reduce grazing by hyperabundant deer. Prior to erecting the fence, this area had been cleared of invasive species. Over 10,000 native plants were grown in a nursery from seed that was hand-collected on the site and then planted within the fenced area. As a result, the abundance of native species has increased.
Deltoid balsamroot, listed as endangered under the Species at Risk Act, was last seen at the fort in the 1960s. In 2001, while doing a plant inventory at the site, the individual who located the plants many decades ago found that the plants were still persisting on a very limited basis. Fencing provided temporary relief from deer browsing, and their flowering success has improved.
By restoring the Garry oak ecosystems, the canopy was opened up to reveal historical view lines that had become overgrown with invasive species of shrubs and trees. In this way, the restoration project enhanced both the natural and cultural heritage aspects of the site.
Staff members whose work focused on cultural heritage resource protection and presentation at Fort Rodd Hill collaborated with the ecosystem recovery team. For example, Daphne laureola (spurge-laurel) is an alien invasive species that was not present during the historical period; therefore, removal was desirable for both ecological and cultural integrity.
Best practices were developed for the control of invasive species. For example, testing of various methods has shown that the most efficient way to control Daphne laureola (spurge-laurel) is to cut down the young plants with a scythe-like tool. The young plants do not flower or set seed for several years; therefore, regular cutting thins out the plants over time.
An efficient photo-monitoring program tracked response to the treatments. This was replicated by university students hired each year through a Cooperative Work Study Program.
Parks Canada staff and volunteers have worked together to control invasive species. Volunteers have included local community members, university students, and Scouts, all of whom have learned about Garry oak ecosystems and participated in hands-on restoration activities. In 2003, over 80 volunteers contributed 543 hours of labour. At the end of the day, volunteers experienced a sense of accomplishment as they stood beside substantial piles of invasive plants they helped remove from Garry oak sites.
Visitors and the public have also learned about and experienced this work through a series of public lectures at local libraries and community centres, as well as through on-site interpreters and interaction with restoration technicians working on the site. In 2004, a large, colourful interpretive sign providing information about Garry oak ecosystems was erected at Fort Rodd Hill. This was the first time that a sign of a more ecological nature had been erected at a site primarily dedicated to history.
Parks Canada is the federal government lead for recovery of Garry Oak ecosystems in Canada, and has worked in conjunction with all levels of government and other partners in this effort. Over 30 agencies have been involved in the overall recovery effort and approximately 80 members have participated on the Garry oak ecosystems recovery team (GOERT) and its various committees.
The number of species at risk has stabilized and is being closely monitored. A photo-monitoring program has tracked response to the treatments and enabled long-term monitoring of large-scale ecosystem and vegetation changes. The approach provided visual evidence of the success of the invasive species removal efforts and was replicated by university science students hired each year through the Cooperative Work Study Program. Long-term monitoring will be necessary to confirm a decline in the soil seed bank.
Project activities and results have been evaluated and reported regularly through a Restoration Project Annual Report, as well as through formal assessment and reporting structures such as Environmental assessment.
- While restoration actions held to the tenet of doing no harm, activities were not stalled because of incomplete knowledge. Work proceeded cautiously, in an experimental format, and was modified based on information and experience gained.
- Using an adaptive management approach was particularly useful in this ecosystem, where knowledge about how to control invasive species and enable recovery of native species was initially limited.
- Biology students were employed to conduct a lot of the work and an ongoing volunteer program was instituted. The greatest success for volunteer recruitment was through personal contacts.
Two full-time staff will be hired to help manage this project along with four summer students. A year-round volunteer program will be implemented. Plans are underway for translocation of two additional rare plant species that formerly occurred in Fort Rodd Hill. Also, interpretation of the natural history of Fort Rodd Hill will be increased , as well as external communications with the public and media. Finally, Parks Canada is hoping to engage interested First Nations groups that wish to tell their story and their relationship with Garry oak ecosystems, such as the use of native food plants like common camas.
For more information
This case study is intended to provide general information about ecological restoration projects in Canada’s protected natural areas. For more detailed or technical information about this restoration project, please consult the following sources, or the contacts provided below.
- Garry oak ecosystems recovery team (GOERT)
- Species at Risk: Fort Rodd Hill and Fisgard Lighthouse National Historic Sites of Canada and Garry Oak Ecosystems
For more detailed or technical information about this restoration project, please contact:
Field Unit Office
2220 Harbour Road
Sidney BC, V8L 2P6
Gulf Islands National Park Reserve of Canada
2220 Harbour Road
Sidney BC, V8L 2P6
If you wish to comment on this case study, please contact Parks Canada at firstname.lastname@example.org