An Alien Invasion

This clump of marsh plume thistle was found at the Research Forest along the South Knolls Trail. It has appeared within the last 12 months and currently measures more than 180cm tall.

Marsh plume thistle (Cirsium palustre), listed as a noxious weed in BC’s Central Interior by the Invasive Plant Council of BC,  is  showing it’s  presence in ALRF’s harvest areas. The plant grows in moist locations and competes with native plants and crop trees. A containment program for this purple-flowered plant is currently underway in the Central Interior aimed at preventing  its expansion. According to the IPCBC  the most effective way to  limit the spread of the species is  by  cutting the plants  down before they go to seed. Other methods such  as biological controls and herbicides are in development.

Last summer, several harvest areas on the Research Forest were surveyed for invasive plants and several  species were found in varying quantities. This provides excellent baseline information to help ALRF monitor increases and decreases in the diversity and abundance of invasive plants and to  implement  strategies for managing them.