Alaska Melilotus Invasions: Distribution, Origin, and Susceptibility of Plant Communities

Melilotus alba and M. officinalis were introduced to Alaska in 1913 as potential forage crops. These species have become naturalized and are now invading large, exotic plant–free regions of Alaska. We determined distributions of M. alba and M. officinalis in Alaska from surveys conducted each summer from 2002 to 2005. Melilotus alba and M. officinalis occurred at 721 and 205 sites, respectively (39,756 total sites surveyed). The northward limit for M. alba and M. officinalis was 67.15°N and 64.87°N, respectively. Both species were strictly associated with soil disturbance. Melilotus alba extended no farther than 15 m from road edges except where M. alba on roadsides met river floodplains and dispersed downriver (Matanuska and Nenana [...]