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cover sample was also taken). All woody plants, including seedlings, with root crowns found within the quadrat boundaries were tabulated by species and by life stages as follows: seedling, mature, or dead. For shrubs that sprout from along-lived root system, such as snowberry (~ymohoricarpos rotundifolius), serviceberry (Amelanchier alnifolial, Gambel's oak (Duercus gambeliil, and chokecherry (Padus virginiana ssp. melanocaroal, individuals were counted as 'clumps' that appeared to originate from the same central root system. For these species, the actual number of individuals present in a stand of woody shoots is highly debatable and such determinations inevitably vary between observers, introducing more variance into already variable sample data. Quaking aspen ( ulus tremuloides) were counted as individual stems, even though it is well known that the trees within thousands of square meters of a typical aspen stand may represent the root sprouts of very few or even a single individual. Plant Species Frequency and Dengj!)f Measurements During the course of cover sampling, all plant species occurring within one meter on either side of the cover transact were noted on the cover data sheets. Frequency for each plant species observed during sampling was calculated by dividing the number of sample transacts in which the species was observed by the total number of samples. As such, this value may be mare correctly termed 'constancy.' Relative vegetation cover was calculated by dividing the absolute cover of each species by the total vegetation cover and expressing the result as a percent. The total number of species (within each lifeform) observed in each sample provide a measure of 'species density', in the units of number of species per 100 sq.m. These measures provide an indication of relative species richness. Plant Species Llsting During the course of the field work, a list of all encountered plant species (quantitatively plus incidental observations) was compiled. Scientific names used follow Weber and Wittman (1992); common names cited may be found in Beetle (1970), Nickerson et al. (1976), or SCS (1979). Cross reference to the substantially revised scientific nomenclature for the flora of Western Colorado, as set forth by Weber (1987), may be determined by reference to Weber and Wittman (1992). Of plant species observed, only Canada thistle (Cirsium arvensel, yellow toadflax (Linaria vulgaris), whitetop (Cardaria • drabal, and common bindweed (Convolvulus arvensisl are listed state-wide as noxious weeds (Thornton et al. 1974). Blue lettuce (Lactuca pulchella), pennycress (Thlasoi 3