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be related to a competitive effect originating with the small size of this species, wherein <br />Bouteloua thrives when cover of larger species is reduced during dry years. Calamovilfa <br />• longifolia, though a warm season grass, shows greater relative cover during average and <br />wet years in the reference azea. To achieve full growth, Calamovt fa appeazs to require <br />more moistwe and a longer overall favorable growing season. Stipa virtdula, though a <br />cool season grass, responds in the opposite manner of Calamovilfa, with highest relative <br />cover values during normal and dry yeazs. Artemista filifolia continues to maintain a <br />relatively constant presence in the reference azea as shown by the relative cover values. <br />This species appears relatively unaffected by precipitation, likely due to its woody habit. <br />1995 Reclamation Areas <br />The 1995 reclamation areas have been sampled quantitatively for the last fow growing <br />seasons. A total of thirty-three species have been encountered in vegetation sampling since <br />1998. Of those species, eleven were present in each year of the sampling. These species <br />included six perennial cool season grasses, two perennial warm season grasses, one annual <br />cool season grass, one native annual forb, and one perennial native forb. <br />No one species has shown consistent yearly increases in relative cover over the period of <br />sampling. However, several perennial species show stable contributions during the last <br />four growing seasons, including Agropyron cristatum, Agropyron dasystachyum, <br />Agropyron intermedium, Bouteloua gracilis, Calamovilfa longifolia, and Oryzopsis <br />hymenoides. The perennial native forb Ambrosia psilostachya has maintained a constant <br />presence throughout the cover sampling. While the annual forb Kochia scoparia has <br />• continued to generally decrease in overall relative cover over the last four growing <br />seasons, Bromus tectorum relative cover doubled this year (compared with 2000) due to <br />the favorable precipitation regime. <br />Of the important species in the 1995 reclamation areas, Agropyron dasystachyum and <br />Agropyron tntermedium have slowly increased in relative cover over time while <br />Agropyron smtthii has decreased. Bouteloua gracilis increased in relative cover the first <br />three years and decreased slightly this wet year, possibly due to the competition effect <br />posed above. Bromus marginatus and Bromus tectorum both appear to respond directly <br />to precipitation amounts, and increase relative cover in average and wet years, while <br />decreasing in dry years. Oryzopsis hymenoides has shown a general decrease in relative <br />cover over the past four yeazs, and Panicum virgatum has appeared and increased the last <br />two years. The two forts consistently present are Ambrosia psidostachya and Helianthus <br />annuus. Unlike the other forb species, these two appear little impacted by precipitation <br />regime, possibly due to their adaptations to dry conditions, waxy cuticles, pubescent <br />epidermis, and in the case ofAmbrosia, small statwe. <br />1997 Reclamation Areas <br />• Quantitative sampling has been undertaken in this area for the past three growing seasons. <br />During this time thirty-one species have been encountered. Of those species, seven have <br />-20- <br />