ANDERSON, ROGER C, JANEEN LAATSCH, & MICHELLE SIMONE.
Department of Biological Sciences, Illinois State University, Campus Box 4120l, Normal, IL 62901-4120 USA.
During restoration of native prairies, late-successional species associated with high quality remnant prairies often fail to become established or do not appear on the site until a matrix of aggressive, early-successional prairie plants dominate the restoration. It was hypothesized that changes in the mycorrhizal community during restoration facilitate establishment of late successional species. We examined variation in mycorrhizal inoculum potential, and growth and arbuscular mycorrhizal colonization for early (Canada rye, Elymus canadensis) and late (Little bluestem, Shizachyrium scoparium) successional prairie grasses, in soils obtained from three restored prairies of varied ages (2, 11, and 17 years old). Soil from the oldest restoration site had a significantly higher inoculum potential than soils from the other two restoration sites. For little bluestem, there were no significant differences in colonization among plants grown in the three soils. Canada rye colonization was significantly higher in the 2-year old restoration site soil than in soil from older sites. Canada rye had lower colonization than little bluestem when grown in soils from the oldest restoration site. Little bluestem root mass was significantly greater for plants grown in soil from the oldest restoration site than for plant grown in soil from younger sites. Root mass of Canada rye differed significantly among soils from the different-aged restorations, but was greatest in the intermediate-aged restoration. For both species, plants grown in soil from the 12-year old site produced more shoot mass than plants grown in soil from the 2-year old site.