Author
ASAY, KAY - RETIRED ARS | |
Chatterton, N | |
Jensen, Kevin | |
Jones, Thomas | |
Waldron, Blair | |
Horton, William |
Submitted to: Arid Land Research and Management
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 4/11/2003 Publication Date: 11/4/2003 Citation: Asay, K.H., N.J. Chatterton, K.B. Jensen, T.A. Jones, B.L. Waldron, W.H. Horton. 2003. Breeding Improved Grasses for Semiarid Rangelands. Arid Land Res. and Manage. 17:469-478. Interpretive Summary: Large areas of America's rangelands are severely degraded and infested with troublesome exotic weeds such as cheatgrass. In many instances, re-vegetating these areas with new varieties of perennial grasses is the most economical and plausible means of reclamation. The preferred method is to use native species; however, many of these plant materials are difficult to establish and do not compete as well with weedy grasses as their introduced counterparts such as crested and Siberian wheatgrass. The use of seed mixtures involving both native and certain introduced (naturalized) grasses is proposed. Introduced grasses could also be used as an "ecological bridge" to assist in establishment of natives on harsh range sites. Genetically improved germplasms and varieties of native and introduced grasses have and are being developed by the Forage and Range Research Laboratory of the United States Department of Agriculture - Agricultural Research Service (USDA-ARS) in cooperation with the Utah Agricultural Experiment Station, and other agencies. These plant materials have demonstrated the potential for increasing the biological diversity, protecting watersheds and soil resources, and improving the habitat and grazing potential for livestock and wildlife on semiarid rangelands. The selection of varieties to be used on rangelands must be based on objective criteria if we are to protect our lands and natural resources from further degradation. Technical Abstract: Vast areas of semiarid rangelands in western USA are severely degraded and infested with troublesome weeds such as cheatgrass (Bromus tectorum L.) and medusahead rye (Taeniatherum asperum (Sim.) Nevski). Re-seeding with appropriate plant materials that are adapted to the site and competitive enough to replace existing undesirable vegetation is often the most plausible way to reclaim such sites. Unfortunately, many of our native grasses are more difficult to establish and are not as competitive with these exotic weedy grasses as their introduced counterparts including crested and Siberian wheatgrass (Agropyron cristatum (L.) Gaertn.; A. desertorum (Fisch. ex Link) Schultes; and A. fragile (Roth) Candargy). Most native grasses did not evolve under intense management or in association with species as competitive as cheatgrass. Genetically improved germplasms and cultivars of native and introduced (naturalized) grasses have and are being developed by the Forage and Range Research Laboratory (FRRL) of the United States Department of Agriculture - Agricultural Research Service (USDA-ARS) in cooperation with the Utah Agricultural Experiment Station (UAES), and other agencies. These plant materials have demonstrated the potential for increasing the genetic diversity, protecting watersheds and soil resources and improving the habitat and grazing potential for livestock and wildlife on semiarid rangelands. Research is also in progress at FRRL to develop germplasm and methodology whereby introduced grasses may be used in combination with natives, and in some instances assist in the establishment of native stands. The proper choice of plant materials must be based on objective criteria if we are to protect our lands and natural resources from further degradation. |