Assessing Spread and Impacts of Non-native Plants from Highway Corridors in the Northwest Territories (NWT), Canada

ABSTRACT

Species invasions are recognized as one of the leading threats to biodiversity globally and have been associated with declines in native species and changes in ecosystem function, disturbance regimes, species community composition and structure, and species interactions. Invasions are often strongly associated with human disturbances and increased propagule pressure. Thus, transportation corridors like roads, which experience ongoing disturbance as well as potentially large numbers of unintentional introductions of non-native plant propagules due to vehicular traffic, are often key pathways for the introduction and spread of non-native species into remote areas. Additionally, spread of non-native plants away from these anthropogenically-disturbed corridors into natural areas, including into natural disturbances in particular, is increasingly being documented. Here, Singer discusses the spread and impact of non-native plants and distinguishes between the different selection factors operating at each stage of the invasion process.