A network model to help land managers predict and prevent spread of invasive plants from roads to river systems in Alaska

Abstract

Alaska has relatively few invasive plants, and most of them are found only along the state's limited road system. Melilotus alba, or sweetclover, is one of the most widely distributed invasives in the state. Melilotus has recently moved from roadsides to the flood plains of at least three glacial rivers. We developed a network model to examine the spatial relationships between roads, river crossings, and downstream public lands of high conservation significance in interior and south-central Alaska. In 2005 and 2006, we documented the distribution of Melilotus on roadsides and near river crossings in interior and south-central Alaska. Considered together, the distribution data and the network model identify road-river interfaces that potentially expose public land downstream to invasion. We have developed the GIS data layers and compiled our results into summary tables so that land managers may execute queries to extract relevant information for their conservation unit. For example, a land manager may query a list of crossings upstream from a particular wildlife refuge. A transportation manager can extract a list of crossings with Melilotus on the roadside and adjacent flood plain along a particular stretch of road. We hope to partner with spatial data infrastructure providers to make these attribute queries, as well as customized maps, more widely available. Our work to date is focused on a single invasive species, but is intended to provide a general modeling framework to address the spread of invasive species along arctic and subarctic roads, and onto adjoining wildlands.

Citation

Macander, Matthew J.; Wurtz, Tricia L. 2007. A network model to help land managers predict and prevent spread of invasive plants from roads to river systems in Alaska. Yellowknife, Northwest Territories, Canada: International Polar Year Committee. 10 p.