Copyright Jeff Selleck
Conestoga wagons at Scott Bluff National Monument, Nebraska.
Prairie restoration is a management priority of Scotts Bluff National Monument, Nebraska. More than 365 ha (900 acres) of formerly agricultural land have been added to the park since it was established in 1919. Restoration was necessary to return the vegetation to its condition at the time of migration on the Oregon Trail in the mid-1800s. The park lies in the northern mixed-grass prairie where the original plant community was the Agropyron-Hesperostipa association. Dominant species included threadleaf sedge (Carex filifolia Nutt.), needleandthread (Hesperostipa comata [Trin. & Rupr.] Barkw.), western wheatgrass (Elymus smithii [Rybd.] Gould), blue grama (Bouteloua gracilis [Willd. ex Kunth] Lag. ex Griffiths), buffalograss (Buchloe dactyloides [Nutt.] Engelm.), and many forbs. Much is known about propagation of the grasses, but little is known about threadleaf sedge. Its seed production is extremely low and most efforts to propagate threadleaf sedge have ended in failure. This important native component of the vegetation is valuable for soil stabilization in this windy environment and it provides food for many species of wildlife. Since threadleaf sedge is one of the dominant species in the native plant community, restoration cannot be considered to be complete without this species.
Scotts Bluff National Monument has a long history of grass restoration on previously farmed and other disturbed sites. Sod was transplanted around a newly constructed parking lot in the 1930s, but the first seedings more than 30 years ago included only a few species of grasses. Though these seedings provided perennial grass cover to the land, they were not prairie restorations. Prairie restorations are aimed at recreating the historical vegetation and more fully restoring ecological function to the land. In 1997, the National Park Service and the University of Nebraska used a $124,000 grant from the Nebraska Environmental Trust Fund to begin restoration of the former site of the Scotts Bluff Country Club that was incorporated into the national monument in 1975. The work included removal of building foundations, a swimming pool, irrigation canals, and nonnative trees and was followed by land contouring, native seed purchases, and preliminary research on threadleaf sedge propagation. Park staff planted seed mixtures of native grasses and forbs in two restoration units (12 ha and 5 ha; 29.7 acres and 12.4 acres). Success of those seedings has been rated as excellent by restoration specialists.
Threadleaf sedge, one of the main components of the native park vegetation, was not included in the restoration because seeds were not available. Research conducted in the park by the University of Nebraska has shown that both seed production and germination for this species are extremely low (Griffin 2002; Fassett 2003). In order to fully restore the vegetation community to meet park goals, greenhouse-grown threadleaf sedge plants would need to be transplanted in the old golf course site. Though research at the University of Nebraska is investigating ways to enhance seed production and establish this species from seed, techniques are incomplete and seeds are not commercially available. Additionally, the university’s research on vegetative propagation has shown that transplanting plugs of sod was not successful; however, transplanting greenhouse-grown plants into the plant community has been highly successful (Tichota 2000; Stubbendieck et al. 2002). In the late fall and early spring of 2002–2003 and 2003–2004, we investigated the success of a transplant method to incorporate threadleaf sedge, taken from the park and propagated in the greenhouse, back into the restoration units at the national monument.
Tunnell, S. J., J. Stubbendieck, R. Manasek, and G. Willson. 2006. Restoration of threadleaf sedge at Scotts Bluff National Monument. Park Science 24(1):48–50.
Available at http://www.nature.nps.gov/ParkScience/archive/PDF/Article_PDFs/ParkScience24(1)Summer2006_48-50_Tunnell_et_al_2522.pdf.