| The economic impact of three invasive, exotic weeds--diffuse, spotted, and Russian knapweed (Centaurea diffusa, C. maculosa, and Acroptilon repens)--on Montana's economy was estimated using a procedure developed for another invasive weed species. Published data and that from a survey of county weed boards were used to estimate direct negative impacts of over $14 million annually due to infestation of over 2 million acres of rangeland and wildland. This amounts to about $10.63 on each infested grazing land acre and $3.95 on each infested wildland acre. Direct plus secondary economic impacts, estimated using an input-output model, are about $42 million annually, which could support over 500 jobs in the state's economy. This first approximation suggests... |
