02235nas a2200157   4500008004100000245010500041210006900146300001500215490000700230520163800237653002201875100002001897700001701917700001801934856012501952       1989                        eng d00aRelationship between mycorrhizal dependence and competitive ability of two tallgrass prairie grasses0 aRelationship between mycorrhizal dependence and competitive abil  a2608 -26150 v673 a<p>The impact of mycorrhizal symbiosis on growth of Andropogon gerardii (big bluestem) and Koeleria pyranidata (junegrass) was compared. Andropogon gerardii was 98% dependent on the symbiosis, whereas K. pyranidata displayed less than 0.02% dependence. Mycorrhizal fungus inoculation resulted in 50 times larger A. gerardii plants but did not alter growth of K. pyradidata. When competing in pairs, A. gerardii dominated when the mycorrhizal symbiosis was present and K. pyradidata dominated when it was not present. Dry weight of mycorrhizal A. perardii was altered, whether grown alone or with K. pyranidata, but mycorrhizal K. pyranidata grew well only in the absence of competition and failed to grow appreciably if A. gerardii was present. Without mycorrhizal fungus inoculation, A. gerardii did not grow and had no deleterious effects on K. pyranidata. When P. fertilization was substituted for mycorrhizal fungus inoculation, A. gerardii grew better alone than in competition with K. pyranidata at low P levels but was not affected by competition at high P levels. Koeleria pyranidata was not affected by competition at low P levels, but high P fertilization resulted in reduced dry weight of K. pyranidata plants when in competition with A. gerardii. Phenologic separation of growing seasons avoids interspecific competition between these two grasses and may be one mechanism contributing toward their coexistence. Since low temperatures limit mycorrhizal nutrient uptake, phenologic separation of growing seasons could also avoid the competitive advantage of warm-season grasses conferred by their mycorrhizal dependence</p>10atallgrass prairie1 aHetrick, B.A.D.1 aWilson, G.T.1 aHarnett, D.C.  uhttp://knz.lternet.edu/content/relationship-between-mycorrhizal-dependence-and-competitive-ability-two-tallgrass-prairie