-by Aimée Pelletier, Ecosystem Scientist, Parks Canada Agency
Parks Canada is the lead agency responsible for the protection and recovery of more than 40 species listed under Canada’s Species at Risk Act (SARA) that inhabit Garry oak and associated ecosystems. One of the goals of the Garry Oak Ecosystem and Species at Risk Recovery (GOESARR) Project is to assist in the recovery of Garry oak species at risk by introducing some of these species to suitable sites in Gulf Islands National Park Reserve and Fort Rodd Hill National Historic Site. Although there is no substitute for ecosystem protection when it comes to conserving rare species, there are instances where translocation (introduction or re-introduction) of a rare species is the best option for endangered species recovery.
For example, the endangered golden paintbrush (Castilleja levisecta) is restricted to only two small island populations off of Victoria, BC in Canada and to nine populations in the United States. The Recovery Strategy for Multi-Species at Risk in Maritime Meadows Associated with Garry Oak Ecosystems in Canada identifies as a recovery goal for this species the establishment of at least 7 new populations. Surveys of potential golden paintbrush habitat in Gulf Islands National Park Reserve determined that a small islet located at the south end of the park reserve is the best available site for supporting a new population.
Golden paintbrush seed was collected from a Canadian donor population near Victoria in August 2008 and entrusted to a local nursery for germination testing and propagation with fingers crossed that the seed would be viable (it was!). Once fall rains moisten the islet’s soil, a small team of hopeful biologists will be transplanting 250 precious seedlings into experimental plots. While several translocation attempts (some successful) have been made in the United States, this will be the first experimental translocation attempt in Canada.
Unlike the rich and protected greenhouse environment where the seedlings have been raised, these tender shoots will face a number of challenges in their new location, including potential trampling and herbivory by river otters (Lontra canadensis) and Canada geese (Branta canadensis) that use the island, competition with invasive species, and summer drought conditions. Research indicates that the limiting factor for seedling survival after transplanting is the drought conditions they face during their first summer in the field. This is why a third of the transplanted seedlings will receive supplemental watering treatment during the hot, dry summer months. Another third will receive supplemental fertilization in addition to water. A control group will receive neither water nor fertilizer.
The survival, growth, and reproductive output of the seedlings, as well as signs of trampling, herbivory, disease and competition with invasive species, will be monitored closely over the next several years to assess project success. If necessary, invasive species will be managed within the experimental plots. It is hoped that the information gained from this small-scale experimental translocation will not only inform future translocation efforts to establish long-term persistent populations at this and other Canadian locations but may also help determine management options for existing populations, some of which appear to be in decline.
Let’s keep our fingers crossed that these tender green shoots make it through the many challenges ahead! For more information about this project, contact Aimée Pelletier at Parks Canada Agency.