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

RECOMMENDATIONS FOR FUTURE RESEARCH AND MONITORING

It is apparent from field observations and research papers that sulphur cinquefoil, Dalmatian toadflax and leafy spurge are highly adaptable weeds that have the ability to infest much of the grassland and open forest of the Bunchgrass, Ponderosa Pine and Interior Douglas-fir biogeoclimatic zones within the Montane Cordillera. While a considerable amount of information on sulphur cinquefoil has been compiled by Powell (1996), further research on all three species is required to determine the following information:

Similar information, particularly on ecological amplitude and potential distribution, should be gathered on any species that are similarly detrimental to natural areas in the Ecozone.

In any weed management plan, the process of information gathering is essential and continuous. In addition to staying abreast of advances in control techniques, effective weed management is contingent on frequent and accessible inventory and monitoring programs (Hoglund et al. 1991). Monitoring provides baseline data to compare one season with another, and is a tool for measuring progress, effectiveness and actual costs (Hoglund et al. 1991). The challenge of monitoring and controlling weeds requires a cooperative effort of citizens, government agencies (regional, provincial and federal), non-government organizations, First Nations, livestock associations and utility companies. Several Weed Committees have been organized within the Montane Cordillera, to address the major environmental threat of invasive non-native vegetation in rangelands and natural habitats. It is important that these committees coordinate their efforts while they endeavour to encourage agency coordination, prioritize management activities and to provide public information programs for weed management within their respective jurisdictions. Multi-agency coordination prevents duplication of effort, broadens the availability of specialists, substantially reduces the cost for participants and increases the effectiveness of weed control programs. Cooperation should be encouraged with agencies in Washington to increase the knowledge, experience, financing and success. Similar climate and topography create a natural geographic unit that crosses the BC:Washington border. Information on weed spread and new weed species could significantly assist the monitoring program.

Attempts to control weeds must address the causes of the invasion. There has been little examination of the management of weed populations and the implications of changes in land use practices. Most of today’s weed problems arise from past and present human activity. Changes in human behaviour are required to deal with current weed problems and to minimize future problems (Hobbs and Humphries 1995). Prevention and early detection of weeds are critical weed management measures, and their importance needs to be recognized. Lack of early treatment can lead to the development of a major weed problem, and this process can be exacerbated by inappropriate land management practices (Hobbs and Humphries 1995).