…from the Western Wildland Environment Threat Assessment Center, US Forest Service…

“Most of Alaska’s invasive plants are found only along the state’s limited road system, and Melilotus alba is one of the most widely distributed invasives in the state. Recently, Melilotus has been found to have moved from roadsides to the flood plains of at least three glacial rivers. In one of these cases, Melilotus has become a major component of the flood plain vegetation of the lower Stikine River in southeast Alaska, within the Stikine-LeConte Wilderness. The presence of Melilotus on the lower Stikine River points out the vulnerability of roadless public lands in Alaska to invaders dispersing via linked road-and-river networks. Because more and more noxious species are turning up in Alaska each year, and because they are also spreading along the roadsides, it is likely that other species will follow the roads-to-rivers route that Melilotus has taken. The objective of this project is to develop a simulation model of the potential spread of an invasive plant along roads and river networks in Alaska. The model will allow us to predict the rate of spread, and the number of years until an invasive plant will reach different roadless public conservation units. It will identify certain road-river interfaces and crossings as critical control points for certain public lands conservation units. This information will provide a means of prioritizing and evaluating the effectiveness of different management responses to invasive species in Alaska. The model will highlight which public lands are most vulnerable to invasion via linked road and river networks, as well as showing which lands are least vulnerable. We will be able to use the model to test hypotheses concerning climate change and changing flood regimes, for a variety of management actions and for a variety of invasive species. Initial model development will focus on a 10,000 km² study area (100 by 100 km) comprising the rivers and roads upstream of the Kanuti National Wildlife Refuge (NWR), north of Fairbanks. This area is bounded on the east by the Dalton Highway, and on the west by the western boundary of the wildlife refuge. Kanuti NWR is entirely located in National Hydrography Data set subregion 1904, and although it has no direct road access, there are 13 major and 112 minor crossings upstream of the refuge, all on the Dalton Highway. When the model is functioning properly on this relatively small test area, we’ll expand it to larger extents, with the goal of scaling the model up to the full extent of interior and south-central Alaska.”

• More information