The project consists of a weed inventory along roads in the Lapwai and Big Canyon Creek watersheds. The survey was conducted in 2005 and 2006 and was funded by the Bonneville Power Administration as part of an anadromous fish restoration effort. The project was completed by the Nez Perce Soil and Water Conservation District.
Noxious weeds are an ever-increasing threat to native ecosystems. Weeds have a variety of detrimental effects including degrading wildlife habitat, crowding out beneficial native plants, choking steams and waterways, poisoning or injuring livestock and humans, and fouling recreation sites (Prather et al. 2002).
Weeds can affect anadromous fish habitat in many ways. Most weeds are annuals, which typically have less extensive root systems than the perennial native riparian vegetation. Most native riparian vegetation root systems provide stability for stream banks and reduce erosion. Weeds will also crowd out wetland plants common along stream banks and transitional areas. Many wetland plants act as filters reducing excess nutrients and trapping fine sediments before they reach the stream. Additionally due to their highly competitive life strategies, weeds can reduce recruitment of trees and shrubs which provide canopy cover that help maintain cool water temperatures.
Noxious weeds cost the U.S. $7.4 billion in lost productivity and $300 million is lost due to weeds in Idaho alone. Noxious weeds can spread at an alarming rate, increasing their acreage up to 14 percent per year (ISDA 1999). Roads are one of the primary pathways noxious weeds are spread across the landscape (Sheley et al. 2002, and Rooney et al. 2004). Weeds generally establish quicker in the disturbed, open areas along road corridors, and they often out-compete native vegetation in areas of disturbance.
- Obtain a baseline weed inventory for public roads within the watershed.
- Identify target weeds for management.