Brooks Range
Grizzly along the Denali Highway Rafting the Gulkana National Wild River Native woman drying salmon on racks ATV rider on trails near Glennallen Surveyor
BLM>Alaska>Programs>Invasives Species>Noxious & Invasive Plants
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What is a Weed?

The definition included here tries to incorporate the concepts of public land health and sustainability. A weed is defined as "a non native plant that disrupts or has the potential to disrupt or alter the natural ecosystem function, composition and diversity of the site it occupies. It 's presence deteriorates the health of the site , it makes efficient use of natural resources difficult and it may interfere with management objectives for that site. It is an invasive species that requires a concerted effort (manpower and resources) to remove from its current location, if it can be removed at all." (adapted from Noss and Cooperider (1994))

What is a noxious weed?

The term "weed" means different things to different people.  In the broadest sense, it is any plant growing where it is not wanted.  Weeds can be native or non-native, invasive or non invasive, and noxious or not noxious. 

Legally, a noxious weed is any plant designated by a Federal, State or county government as injurious to public health, agriculture, recreation, wildlife or property. (Sheley, Petroff, and Borman,1999)

A noxious weed is also commonly defined as a plant that grows out of place   (i.e. a rose can be a weed in a wheat field) and is "competitive, persistent, and pernicious." (James, et al, 1991).

Are invasive plants the same as noxious weeds? 

No.  Invasive plants include not only noxious weeds, but also other plants that are not native to this country.  The BLM considers plants invasive if they have been introduced into an environment where they did not evolve.  As a result, they usually have no natural enemies to limit their reproduction and spread (Westbrooks, 1998).  Some invasive plants can produce significant changes to vegetation, composition, structure, or ecosystem function. (Cronk and Fuller, 1995).