Invasive Species
Beware of giant hogweed
Giant hogweed is an invasive species with broad leaves and a dense canopy that can out-compete the growth of many native species. It can also pose a serious health risk since its stalks, leaves and bristles contain a noxious sap that sensitize skin to sunlight.
Giant hogweed has been reported in the NVCA watershed in the towns of Collingwood, Mono, New Tecumseth and Wasaga Beach and the townships of Adjala-Tosorontio, Clearview and Essa.
For more information on giant hogweed, please click here.
Garlic mustard infestations being tracked along Bruce Trail
The extent of garlic mustard infestation along sections of the Bruce Trail in the NVCA watershed was documented during the summer of 2009 by NVCA staff (including an Ontario Federation of Anglers and Hunters Invasive Species Program student), Fred Nix (NVCA board member) and several volunteers.
Garlic mustard is an invasive plant species that can quickly invade and dominate the forest floor, limiting or eliminating the growth of native species such as trilliums and violets. In North America, Garlic Mustard has a lack of natural predators. It also has a fast growth rate and can disperse 15,000 seeds per plant, which remain viable in the soil for up to five years.
Garlic mustard has begun to colonize the NVCA watershed. Heavy infestations were observed along some trail sections in the Hockley Valley, the Nottawasaga Bluffs Conservation Area and Pretty River Valley Provincial Park. Lighter infestations were observed at Petun Conservation Area.
The Bruce Trail was selected for monitoring for the following reasons:
- portions of the trail run through three NVCA-owned lands
- some sections of the trail run through provincially and regionally significant Areas of Natural and Scientific Interest (ANSIs)
- there is evidence that garlic mustard seeds can be inadvertently spread by hikers, leading to further infestation.
The monitoring methodology consisted of hiking along the trail and recording various parameters when garlic mustard was encountered, including the shape of the garlic mustard patch (linear or polygon), the geographical location of the start and end of the patch and the estimated number of plants in the patch.
Many garlic mustard infestations were observed near parking areas and trail access points. This suggests that garlic mustard seeds are inadvertently being carried by hikers' footwear along the trail system and being introduced to previously unaffected areas.
The final report provides recommendations for garlic mustard control which will hopefully be implemented by agencies and volunteer groups to keep this invasive species at bay. The NVCA plans to continue working with the Bruce Trail Conservancy and the OFAH to monitor the Bruce Trail.
To read the full report, please click here.