Identifying Geographically Based Metapopulations For Development Of Plant Materials Indigenous To Rangeland Ecosystems Of The Western Usa

Rangeland ecosystems account for about half of the earth's land surface. They play an important role in providing forage for livestock and wildlife, and they serve as critical watershed areas. Many of the world's rangelands have been degraded by overgrazing, marginal crop production, mineral and energy extraction, recreation, and other human-caused disturbances. This degradation has led to invasion by exotic weeds and subsequent increases in fire frequency. This, in combination with uncertainties associated with global climatic change, has resulted in a critical need for plant materials to restore and revegetate rangeland ecosystems. The assessment of genetic variation and its phenotypic expression in important rangeland plant species (especially forbs) is critical in defining population structures (genetically differentiated groups) that could be used in rangeland restoration/revegetation efforts. We used common-garden studies and DNA-based analysis of genetic variation to assess genetic diversity in three rangeland legume species indigenous to rangeland ecosystems of the Great Basin Region of the western USA. Results of these studies are presented as three case studies that describe data collection procedures, analysis, and interpretation used to identify population structures in each species. These data formed the basis for combining plant collections into geographically based metapopulations for these three legume species that are being used to develop plant materials for commercial seed production and subsequent use on rangelands of the Great Basin.