02183nas a2200145   4500008004100000245014500041210006900186300001300255490000700268520158400275100002001859700001701879700001901896856012201915       2004                        eng d00aCompetitive relationships of Andropogon gerardii (big bluestem) from remnant and restored native populations and select cultivated varieties0 aCompetitive relationships of Andropogon gerardii big bluestem fr  a451 -4570 v183 a1Although genetic differentiation among plant populations is well known, its relevance for preserving the integrity of native ecosystems has received little attention. In a series of competition experiments with Andropogon gerardii Vitman, a dominant species of the North American Tallgrass Prairie, plant performance was related to seed provenance and restoration activities.
2Glasshouse experiments showed plant performance to be a function of seed source. Differential target plant performance relative to competitor identity was observed when plant performance was assessed across a range of competitor densities. Local and non-local plants were larger when competing against non-local plants relative to the local and cultivar plants, while cultivar plants were consistently larger than local and non-local plants regardless of competitor identity or density. The consistency of cultivar performance could reflect directional selection during cultivar development for consistently high fecundity, vigorous vegetative growth and resistance to pathogens.
3In a field experiment, non-local plants were half the size of local and cultivar plants, supporting recognition of seed provenances of A. gerardii based on differences in plant performance among source populations observed in the glasshouse study, and previous genetic analyses of the same populations.
4This study establishes that seed provenance and restoration activities influence the competitive ability of a dominant species which, in turn, may affect plant community structure and potential ecosystem function.1 aGustafson, D.J.1 aGibson, D.J.1 aNickrent, D.L.  uhttp://knz.lternet.edu/content/competitive-relationships-andropogon-gerardii-big-bluestem-remnant-and-restored-native