Browsing by Author "Hebberger, Joanna"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    The Effects of Fire versus Mowing on Prairie Plant Communities
    (2003-07-01) Tix, Daniel; Hebberger, Joanna; Vaughan, Elizabeth; Charvat, Iris D
    The primary goals of this project are to discover management processes which 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.
  • Thumbnail Image
    Item
    Mycorrhizal/Plant Factors Involved in Roadside Reclamation
    (2000-08-01) Charvat, Iris D; Agwa, Hamdy; Hebberger, Joanna; Tallaksen, Joel; Raley, Marcia; Gould, Elizabeth; White, Jennifer; Slack, Sarah
    The main goal of this research was to study mycorrhizal and plant factors involved in roadside reclamation. Our objectives included (1) producing mycorrhizal inocula for incorporation at restoration sites, (2) assessing the properties of soil additives and mycorrhizal inocula in potted greenhouse trials, (3) assessing the effects of soil amendments and maintenance techniques on mycorrhizal/plant parameters on recently established roadside rights-of-way, (4) assessing the longer-term effects of mycorrhizal reintroduction into prairie restoration sites, (5) monitoring mycorrhizal diversity of undisturbed Minnesota prairies for comparison to restoration sites, and (6) monitoring plant colonization in wetland and prairie habitats at a restored roadside site. Fertilization amendments favored the growth of undesirable weedy species and lowered the diversity of native plant species. Hence, the addition of fertilizer did not benefit native prairie plantings and generally is not recommended for use at roadside prairie restoration sites. The fungal inocula incorporated into roadside restoration plots enhanced native plant cover at one location, but had minimal impact at another location. Our results indicate that many factors influence the outcome of fungal inoculation. The mycorrhizal studies of native areas provide an information base against which to compare restored areas. The revegetation studies yielded recommendations for future restorations. Keywords: Prairie and wetland restoration, arbuscular mycorrhizal fungi, fungal inoculum, fertilization, seedbank, burning/mowing