Charvat, Iris D.

The aim of this research is to produce a local, diverse mycorrhizal inoculum for commercial production for use in the Minneapolis/St. Paul area. In earlier studies, spores of several arbuscular mycorrhizal fungal (AMF) species were isolated from a Minnesota remnant prairie and identified by morphological features. For each species, single spore cultures were established and stored in the cold for 6 to 7 years. Objectives of this project were to produce pot cultures from the single spore cultures and to recommend AMF species for commercial production. To check the identity of the fungi before and after inoculum production, genetic identification of fungi used to develop the inoculum should be performed. The extraction and preservation of DNA of AMF species were done. DNA analysis showed general agreement between the morphological and molecular identification of the spores and their placement in genera. However, results suggested that some species placement might not be consistent where these comparisons can be made. Further research may result in the re-naming of some species. Several AMF species are recommended as candidates for commercial inoculum production based on production of spores in pot cultures, on their longevity in cold storage, and in some species on molecular traits.

In this project, researchers studied mycorrhizal and vegetational characteristics at prairie and wetland restoration areas. Study objectives included the following: * quantifying the effect of fungal inoculum on plant communities at a Minnesota Department of Transportation (Mn/DOT) prairie restoration site near Cambridge, Minn. * evaluating the prairie forb germination rates * monitoring revegetation at prairie and wetland restoration sites * characterizing mycorrhizal status of native wetland and prairie areas for comparison to the restored sites * producing fungal inoculum for incorporation into further reclamation areas. Findings indicated that 15 months after planting, fungal inoculation resulted in significantly greater cover by native plant species than seen in control plots. At this site, mycorrhizal inoculation benefited the prairie restoration effort by encouraging earlier, more extensive establishment of the planted species. Ongoing studies at this site will determine the long-term effects of mycorrhizal inoculation on the plant community. The report also presents specific recommendations for future restoration efforts. The studies of mycorrhizae in native prairies and wetlands provide further data for a baseline against which to compare restored areas. In addition, fungal inoculum produced in this project has been incorporated into restoration plots at another Mn/DOT site.

The three objectives of this project were as follows: (1.) to survey the arbuscular mycorrhizal fungi from the prairies, wetlands, and Mn/DOT experimental sites in anticipation of using data as indicators of the sites' health, (2.) to produce mycorrhizal inocula by different methods and (3.) to incorporate the inoculum into a Mn/DOT restoration site. This project was the first year of a three year study that seeks to define the variability in the mycorrhizal spores and other structures present in different ecosystems and determine if these fungi can be used as indicator species. All phases of the project were successful. The preliminary results suggest the mycorrhizal fungal spore numbers will be useful health indicators of restoration sites. General and single spore mycorrhizal inocula were generated using primarily native grasses and forbs as plant hosts. The general inoculum was then incorporated into a Mn/DOT experimental site. Future evaluations of this site will help to answer long-term questions regarding the possible benefits of amending disturbed roadway plantings or other prairie restorations with mycorrhizal inoculum.

This project sought to examine whether it was possible to re-introduce naturally occurring soil fungi called vesicular arbuscular (VA) mycorrhizae back into disturbed soils as part of a normal seeding operation for restoring a prairie. The project consisted of three phases; 1) a survey to determine the types of VA mycorrhizae occurring in different soils and vegetation types (i.e. general roadside, prairie remnant, prairie planting); 2) collect from the wild and then grow prairie VA mycorrhizae species in a greenhouse at the University of Minnesota; 3) install the VA mycorrhizae along with seed from a conventional native seed drill and monitor whether the cultured VA mycorrhizae formed mycotrophic associations with prairie species in the field. This project was a preliminary feasibility study and was not intended to answer long term questions regarding the possible benefits VA mycorrhizae may confer to roadside plantings or other prairie restorations. All phases of the project were successful. The survey indicated that differences in VA mycorrhizae composition exist between different sites. It is possible to produce VA mycorrhizae in a greenhouse by culturing on living plant hosts. The VA mycorrhizae produced was successfully installed along with seed into field plots and did form mycotrophic associations with newly planted prairie species. Preliminary results obtained from this project indicate that further investigation is warranted.

The primary goals of this project are to discover management processes that benefit a restored prairie and reduce the need for prescribed burning. Moreover, because of the interdependence of the plants and soil, there is a strong focus on the soil community as a driving force of the vegetation. Consequently, our objectives were to assess the effects of manipulation (burning, mowing) on: (1) the vegetative community, (2) the belowground mycorrhizal fungal community, and (3) on soil parameters. Prescribed burning has the strongest effects on plant community composition and is the most effective method to increase aboveground plant biomass in a restored tallgrass prairie. Burning especially favors warm season grasses (WSG) and legume species, though it also favors certain annual species. Spring haying is an acceptable alternative to spring burning, though its effects are less dramatic than the burn. In particular, haying does not favor WSG as extensively and may not damage cool-season species as thoroughly as burning. Adding lime to hayed prairie may help benefit the cool-season plants, native and exotic. However, utilizing mowing instead of burning probably does not differ much from leaving the prairie untreated. The process of removing litter seems to be the most important cause of the ecosystem response to prescribed burning. Hayed plots are the most similar to burned plots in terms of soil moisture, temperature, and litter quantity. Hence, litter removal by haying will likely be a sufficient practice to replace prescribed burning at many sites.

This research project examined mycorrhizal and plant factors involved in roadside reclamatin. The addition of fertilizer did not benefit native prairie plantings and generally is not recommended for use at roadside prairie restoration sites.