Scotts Bluff National Monument - Nonnative Species

Scotts Bluff National Monument by National Parks Service

Scotts Bluff National Monument has forty-six nonnative species of vascular plants and five known nonnative terrestrial vertebrate species. The nonnative terrestrial vertebrate species are house finch, house sparrow, rock dove, European starling, and ring-necked pheasant. Funds are spent to control two of the non-native vegetation species - Canada thistle and musk thistle. Both are listed as noxious weeds by the state of Nebraska. Several years ago the monument began an active control program. Personnel began spraying the most extensive areas of Canada thistle infestation with Rodeo, a water safe and relatively mild herbicide. In 1997, 1998, and 1999 the monument and the Scotts Bluff County Weed Authority released several species of biological controls. Since that time the county weed authority has continued to release biological controls throughout the county and near the monument's boundaries. In a few areas the biological controls have made significant impacts on Canada thistle.

Scotts Bluff National Monument also attempts to control musk thistle. Since musk thistle is a biannual the controls used are mechanical. Monument staff use shovels to sever the taproot of the plants approximately four inches below the ground surface. The flower weevil, another biological control, was not released within the monument, but essentially every musk thistle plant examined has some degree of infestation.

Downy brome and smooth brome are the two most serious nonnative grasses that infest the monument. Downy brome is an annual. Smooth brome is a perennial. At the present time prescribed fire is the only tool used to control these two species. It is doubtful prescribed fire alone will significantly control either of these grass species.

In 2002 the Northern Great Plains Network (NGPN) of national park areas initiated an exotic plant management team program. This consisted of a team of personnel who traveled to NGPN areas for the expressed goal of controlling exotic vegetation. Because of the monument's limited funds, this program has greatly improved the control nonnative vegetation.

Scotts Bluff National Monument will never be free of nonnative vegetation. These plants are well established, however, their control within acceptable limits is possible.