A multi-scale framework for evaluating the benefits and costs of alternative management strategies against invasive plants.
Using a bioeconomic model that explicitly accounts for inventory and treatment expenditures, we carry out benefit-cost analyses of management strategies for three invasive plants in British Columbia: hawkweed, Scotch broom and Eurasian watermilfoil. For hawkweed, a province-wide biocontrol programme could achieve greater benefits than a conventional control programme, while for Scotch broom a small-scale mechanical treatment programme applied in a transport corridor was not economically viable unless it prevented spread into the surrounding area. Mechanical treatment of Eurasian watermilfoil in regional lakes generates net benefits to society, but inventory should be a key component of a control programme. Based on these analyses, we recommend continued development of successful biological control programmes for hawkweed and other invasive plant species.