Taking on the invaders
European buckthorn- Venise-Ouest peatland (QC) (Photo by NCC)
Invasive species are one of the leading threats to biodiversity and cause ecological havoc in many sensitive habitats. In an effort to protect native plants and animals across their properties in Quebec, the Nature Conservancy of Canada (NCC) has recently started taking action against many aggressive invaders.
One of them is the European buckthorn, an Eurasian shrub species that was introduced to North America as an ornamental shrub for fencerows and windbreaks in agricultural fields. Since then it has spread aggressively throughout North America thanks to birds and other wildlife that eat its fruits and disperse its seeds. Because of its tolerance of a wide range of ecological conditions, European buckthorn is able to successfully invade many habitats, forming dense thickets that crowd out native shrub species and understory plants. Once established, it is difficult to remove and can regenerate after cutting.
In the late 90s, European buckthorn colonized the Venise-Ouest peatland. This peatland is part of a large wetland northeast of Missisquoi Bay. The entire area is of vital significance, as it shelters a great number of threatened or vulnerable species. In fact, it is home to the wood turtle and the largest population of bog fern in Quebec. Only three populations are observed in the province, the other two being in Clarenceville and North Sutton. This wetland also plays a vital ecological role by filtering some of the water that empties into Missisquoi Bay and absorbing water overflow during spring flooding of Lake Champlain.
Losing this habitat to the profit of an invasive species would be devastating. For this reason, a Conservation Volunteers event was held on July 17 to cut back European buckthorn and prevent it from crowding out the native species that form this unique ecosystem.
Seven motivated volunteers and three Nature Conservancy of Canada (NCC) employees used all their power to pull out three big bags of seedlings and two dozens of saplings using a puller-bear: a tool specifically designed to remove invasive shrubs. In addition volunteers sawed 30 mature shrubs, too large to be removed with a puller-bear. Their stumps were covered with plastic to prevent regeneration.
The area will be monitored over the following years to keep an eye on their comeback and act rapidly if need be. Staff are also considering a planting activity to fill the canopy gaps and prevent invasive species from colonizing them.