PS 13-177 - CANCELLED - Restoration through inoculation: the response of tallgrass prairie plants to native microbial reintroduction

Abstract: Understanding interactions between above- and belowground biodiversity is essential for establishment of grassland ecosystem functionality and native plant diversity during ecological restorations. Plant diversity has long been recognized as an important component of ecosystem functionality, but the role of belowground microbial diversity, such as arbuscular mycorrhizal (AM) fungi, has also recently gained attention. Previous studies have shown AM fungal communities have a pronounced influence over the composition of aboveground vegetative communities. When designing and implementing grassland restoration projects following non-native plant invasions, it is essential to consider the role of both above- and belowground biodiversity, as neglecting the potentially altered AM fungal communities may diminish the successful recovery of invaded grassland ecosystems. At Konza Prairie Biological Station (NSF-LTER) in Manhattan, KS, we established a restoration project following the invasion of a non-native warm-season grass (Bothriochloa bladhii), with a goal of establishing native plant diversity to the site. Bothriochloa. bladhii has been shown to facilitate dominance through the alteration of AM fungal community composition. In an effort to ameliorate these alterations, B. bladhii was eradicated from the site and 24 replicate plots were established to assess the benefits of reintroducing beneficial taxa of AM fungi through transplanting AM fungal-inoculated seedlings. Seedlings of five native prairie plant species (Andropogon gerardii, Pascopyrum smithii, Asclepias syriaca, Ratibida columnifera, and Lespedeza capitata) were established in a greenhouse with one of three AM fungal inocula: whole prairie soil collected from an adjacent undisturbed location, soil with lab/greenhouse selected AM fungal spores, or sterilized soil (nonmycorrhizal control). Reestablishment of B. bladhii, assessment of native plant diversity, and survival of transplanted seedlings were monitored within each plot each year for 6 years. Responses to AM fungal inoculations were plant species-specific. Grass species (A. gerardii, P. smithii) survival was generally not improved following inoculation with either whole soil or selected AM fungal taxa. However, survival of forb species (R. columnifera, L. capitata) was significantly improved when inoculated with either native soil or selected AM fungal taxa, compared to plants inoculated with sterile prairie soil. Survival of A. syriaca was generally low and did not differ between fungal inoculation treatments. Inoculation with AM fungi did not significantly reduce reestablishment by the non-native grass or increase native plant diversity when compared to the nonmycorrhizal control.