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Non-Native Plants on the Mount Baker-Snoqualmie National Forest.

Tracy L. Fuentes, Laura L. Potash, Ann Risvold, Kimiora Ward, Robin D. Lesher, and Jan A. Henderson, USDA Forest Service, Mount Baker-Snoqualmie National Forest

The Mount Baker-Snoqualmie National Forest is one of the most visited National Forests.  More than 5 million people live within a 70 mile drive. The high visitation rate and the proximity to large numbers of noxious weeds and ornamental plants make the Forest particularly vulnerable to the establishment and spread of invasive plants.  To understand the current status and distribution of invasive plants on the Forest, we queried our botany, ecology, and noxious weed databases and GIS layers for all non-native plants.  The resulting data were then analyzed by ranger district and by county.  We examined the spatial distribution of species to understand how invasive plants may have established and to determine which areas are most vulnerable.  In total, 153 non-native species in 28 plant families have been documented.  Of these, 30 are state listed noxious weeds, and 33 are escaped garden ornamentals not currently listed as weeds. We identified the following sources of establishment and spread:  spread from interstates, highways, and power lines that cross the Forest, spread from floods, spread from vehicles directly accessing the Forest, dumping of yard waste, using materials infested with invasive plant propagules, and the deliberate planting of ornamentals.  In addition, several recent land acquisitions included parcels that were already infested with invasive plants.