Lisa Scott. 1998. Weed Invasion in Smith, I.M., and G.G.E. Scudder, eds. Assessment of species diversity in the Montane Cordillera Ecozone. Burlington: Ecological Monitoring and Assessment Network, 1998.

WEED INVASION

Lisa Scott

STATUS REPORT

Provincial Legislation

The British Columbia Ministry of Agriculture, Fisheries and Food has classified some of the most threatening weeds as noxious. Legislation imposes a duty on land occupiers to control designated noxious plants through the BC Weed Control Act. There are currently 21 weeds classified as noxious throughout the entire province and the majority of these introduced plants occur in the Montane Cordillera Ecozone. In addition to the provincial list, nineteen species have been classified as noxious weeds within the boundaries of specific regional districts. The complete list of provincially and regionally noxious species can be found in Appendix A.

As weeds do not recognize land jurisdiction boundaries, it is not surprising to discover that many weeds deemed as noxious in the BC section of the Montane Cordillera also occur in southwestern Alberta. In Alberta, weeds are legally designated as restricted, noxious or nuisance, based on the severity of the problem a species poses. The complete list of restricted, noxious and nuisance weeds of Alberta can be found in Appendix B. Alberta Agriculture, Food and Rural Development administers the Alberta Weed Control Act which requires occupants of the land to:

(a) destroy all restricted weeds located on the land to prevent the spread, growth, ripening or scattering of the restricted weeds,

(b) control all noxious weeds located on the land to prevent the spread, growth, ripening or scattering of the noxious weeds, and

(c) prevent the spread or scattering of nuisance weeds.

Provincial weed acts were established as agricultural aids for controlling plants that may detrimentally affect the agricultural use of land or reduce crop values (White et al. 1993). Consequently, the list of weeds in Appendix A and B represent a very small proportion of the total number of immigrant species entering BC and Alberta. A more thorough list of introduced forbs of British Columbia can be found in Harding (1994).