Germination, survivorship, productivity, and competitive ability of six native grass species from the northern mixed-grass prairie for use in prairie vegetation restoration

I examined establishment capabilities of six major native grasses along a topographic gradient and how these species interact competitively along a moisture gradient. At five sites along a hillside catena at Last Mountain Lake National Wildlife Area, Saskatchewan, Canada, monoculture plots of six native grasses, one invasive exotic, and one "native" cultivar were planted. Competitive ability among five of the native grasses at three moisture levels was studied with a growth-room experiment using Bromus inermis as the reference competitor (phytometer).;A higher proportion of seeds germinated of mesophytic grasses (Agropyron dasystachyum, A. trachycaulum, Bromus inermis, and Festuca hallii) compared to xerophytic grasses (Stipa comata, S. curtiseta, S. viridula, and S. viridula (Lodorm)). The mesophytic grasses and S. viridula (Lodorm) all germinated the first spring. In the remaining xerophytic species, germination varied over two years.;Survivorship and productivity were lower in drier sites. Survivorship of xerophytic species was less affected by variations in moisture availability. Productivity was markedly reduced in the alkaline lowland, except for A. trachycaulum.;Irrigation hastened germination and had a positive influence on total germination and survivorship. Irrigation the first growing season reduced germination of Stipa spp. and productivity in A. dasystachyum and A. trachycaulum in the second year.;Hierarchical competitive ranking differentiated those which are stress-tolerant, often slower-growing, and less competitive (Stipa curtiseta, S. comata, and Agropyron trachycaulum), and those which are more productive, have a higher potential growth rate, and a greater competitive ability (S. viridula and A. dasystachyum). Competitive ability of all the native grasses increased with reduced moisture availability relative to the phytometer. (Abstract shortened by UMI.)...