conducted during the summer of 2003 was aimed to assess the
spread of crested wheatgrass at two known seeding locations on
the INEEL in southeastern Idaho. Crested wheatgrass has been
used historically to revegetate burns and degraded areas on
the INEEL. The focus of this study was to answer the
question "Does seeded crested wheatgrass spread beyond its
planting boundaries and invade native sagebrush steppe
Wheatgrass (Agropyron cristatum) is a long-lived (15-20
years) perennial bunchgrass native to the cold desert regions
of Asia. It was introduced into the United States in 1898, and
became extensively planted in the West beginning in the 1930s.
Crested Wheatgrass is well-suited to semiarid regions and is
primarily used for reclamation/revegetation of rangeland.
Historically, the uses include seeding for weed control (halogeton),
and for increasing the grazing capacity of an allotment. Many
semiarid ecosystems are managed with the assumption that
vegetation will return, or converge, to a native community.
Some crested wheatgrass seedings, however, have resisted the
invasion of native species for as long as 50 years.
The two sites
selected for this study were Lincoln Blvd from Mileposts
11-17, and Tractor Flats, about 5 miles north of Highway 20
near the eastern Site boundary. These sites were selected
because they have 1) at least one documented Crested
Wheatgrass (CWG) seeding, and 2) mapped boundaries to assess
the spread from.
The field data
were collected with GPS receivers by walking the spreading
boundaries. The seeding along Lincoln Blvd was walked in
entirety. The Tractor Flat seeding was partially walked, the
remainder was interpreted from satellite imagery. The GPS data
was corrected and imported into a GIS for analysis.
findings indicate that crested wheatgrass does spread beyond
its initial seeding extent and invades native grass
communities. Several factors influence the rate of spread;
these include fire, grazing, and soil type.
was funded by BBWI and the ISU Geoscience Department.