Theses and Dissertations at Montana State University (MSU)
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Item Restoring semi-arid lands with microtopography(Montana State University - Bozeman, College of Agriculture, 2019) Dillard, Shannon Leigh; Chairperson, Graduate Committee: Anthony HartshornWater is often limiting to plant establishment in semi-arid lands, and this limitation can be especially pronounced in restoration contexts where human legacy impacts and/or non-native plants are present. The application of herbicide and mulch can help retain soil moisture by killing unwanted plant species or lowering evaporative losses, respectively. Creation of microtopography, or soil surface variation, is a third technique that could alleviate growing-season water shortages. Here we report findings from a study that explored the effects of these three techniques combined with broadcast seeding a mix of four native grasses, one native shrub, and one native forb for increasing plant canopy cover and density at three sites in northern Yellowstone National Park. One year after treatment, plant cover in control plots averaged 60%. Across plots treated singly with 1.5% glyphosate herbicide, 3 cm of red cedar mulch, or hand-dug microtopography, only mulch and microtopography increased canopy cover relative to control plots, although the increase consisted mostly of non-native species (>97%). Herbicide, not surprisingly, decreased canopy cover, and that decrease also consisted mostly of non-native species. The herbicide treatment was the most effective in encouraging native species canopy cover and density while simultaneously reducing the same measures of non-native species. Microtopography treatments encouraged growth of all plants (native and non-native), particularly in the micro-lows, but for this to be an effective restoration strategy, non-native species must first be controlled. Although herbicide was quite effective at reducing non-native species populations, particularly at the Cinnabar site, spraying must be timed with the phenology of the existing non-native plant community. We learned that reducing competition with non-native plants does not necessarily encourage native plant growth, which may indicate that growing conditions need to be improved at this site before restoration can be successful. Taken together, our results suggest that soil amendments like microtopography and mulch may have beneficial restoration applications in semi-arid lands but may also show little benefit on a short time-scale in a highly disturbed system. Areas plagued by non-native species invasions and legacy agricultural and grazing impacts are likely to require careful planning of restoration approaches in order to claim long-term success.Item Restoration of spotted knapweed infested grasslands in Glacier National Park(Montana State University - Bozeman, College of Agriculture, 2003) Stringer, Lewis Tipton; Chairperson, Graduate Committee: Catherine A. ZabinskiThere is an immediate and on-going need in Glacier National Park (GNP), and other public and private lands, to determine effective methods to re-establish and sustain native plant populations following control treatments of Centaurea maculosa. My research was developed in response to GNP concerns regarding annual herbicide treatment of C. maculosa invaded sites. The aim of this study was to determine if herbicide applications, site preparation and revegetation methods would increase the density and percent cover of native species, while reducing spotted knapweed at two sites in and near Glacier National Park. A priori contrast analysis was used to determine differences in treatment effects. The results of my experiment show that spot spray herbicide application reduced C. maculosa cover without significantly reducing existing native forbs. However, a repeat-herbicide application increased exotic graminoid cover. Tillage reduced the density of C. maculosa seedlings, but resulted in an increase in C. maculosa percent cover, and an overall decline in native forbs. Revegetation methods had limited success at increasing native species, and reducing C. maculosa. The only effect was at Swift Current, where the percent cover of native forbs was significantly higher with the planting treatment, and most pronounced in plots with repeat-herbicide application. Additionally, we measured the composition and density of the seed bank in C. maculosa dominated sites using the seedling emergence method. C. maculosa density was 3,900 and 6,714 seeds / m 2 at the two sites, which was 2 and 3 times higher than the sum of all other species. Seed bank composition and density needs to be considered in efforts to restore C. maculosa infested areas.Item Absarog-Issawua (from the land of the Crow Indians)(Montana State University - Bozeman, 1970) Toineeta, Joy Yellowtail"This is an original piece of research into the Crow Indian uses of native plants and animals for food and medicinal, as well as other purposes. Incorporated into the manuscript are introductory legends or incidents surrounding or accompanying the recipes."Item Seed dormancy and greenhouse propagation of arrowleaf balsamroot (Balsamorhiza sagittata) and silverleaf phacelia (Phacelia hastata var. hastata)(Montana State University - Bozeman, College of Agriculture, 2015) Bujak, Charissa Maria; Chairperson, Graduate Committee: Tracy A. O. DougherNative plant material, defined by the United States Forest Service, includes all indigenous terrestrial and aquatic plant species that evolved naturally in a defined ecosystem. Native plant material is important for horticultural and restoration purposes; however, propagation protocols for many Montana native plant species remains unknown. This study addressed the following: greenhouse propagation, seed dormancy classification, and seed-dormancy release treatments for arrowleaf balsamroot (Balsamorhiza sagittata) and silverleaf phacelia (Phacelia hastata var. hastata). Additionally, an assessment was completed to better understand current challenges, successes of the Montana native plant market. In this study gibberellic acid (GA3) significantly increased final germination of arrowleaf balsamroot to 81% + or = 2%. Utilizing the Baskin and Baskin (1998, 2004) seed dormancy classification scheme, arrowleaf balsamroot seed dormancy was classified as: 1) nondeep physiological dormancy type 2, 2) intermediate physiological dormancy type 2, and 3) deep physiological dormancy type 1 and 3. Following the Schewienbacher (2011) reclassification scheme, arrowleaf balsamroot seeds were indicative of physiological deep dormancy type 3. In the greenhouse, fertilizer rates up to 200 mg nitrogen/L (20-10-20 NPK of Jack's Professional Peat Lite Special TM) resulted in positive shoot growth but beyond 100 mg nitrogen/L reduced the root-to-shoot value. The Ray Leach Cone-tainer TM was an effective container type. For silverleaf phacelia, 87% + or = 5% germination was achieved within four days with scarification for at least 90 seconds. After 1 year of storage at 5 + or = 1°C, following the Baskin and Baskin (1998) classification scheme, silverleaf phacelia seed dormancy was classified as 1) nondeep physiological dormancy type 1, 2, and 5, and 2) intermediate physiological dormancy type 1 and 2. Addressing nondeep physiological dormancy type 5 would be most effective in breaking seed dormancy. In the greenhouse, fertilizer rates beyond 50 mg nitrogen/L (20-10-20 NPK of Jack's Professional Peat-Lite Special) resulted in positive shoot growth but beyond 50 mg nitrogen/L reduced root mass. The 4-inch square pot was an effective container type. A survey of 30 Montana native plant growers indicated a demand for native plants in the Montana nursery industry. However, more work needs to be completed to develop and stabilize the native plant market.Item Using successional theory to guide restoration of invasive plant dominated rangeland(Montana State University - Bozeman, College of Agriculture, 2003) Anderson, Jennifer Lisa; Chairperson, Graduate Committee: Douglas J. Dollhopf.Item Restoring native species to crested wheatgrass dominated rangelands(Montana State University - Bozeman, College of Agriculture, 2004) Johnson, Janel Denice; Chairperson, Graduate Committee: Bok Sowell.In the 1980's, there were an estimated 7 to 12 million ha of crested wheatgrass (Agropyron cristatum (L.) Gaertn.) in North America. Dense stands of crested wheatgrass lack species diversity, which negatively affects populations of wild mammals, birds, and reptiles. There is new interest among land managers in replacing stands of crested wheatgrass with native species for wildlife habitat, using minimal disturbance techniques such as herbicide and no-till seeding. The objectives of this project were to (1) evaluate the effects of glyphosate on crested wheatgrass and other species and (2) test seedling establishment of native grass and forb seed mixes planted in glyphosate treated crested wheatgrass sod with a no-till drill. Field trials were conducted with two herbicide application treatments and five planting treatments in 2002 and 2003 at five sites in central and eastern Montana. Crested wheatgrass biomass and seedling biomass index were collected in 2002 and crested wheatgrass, seeded species, and non-target species biomass were collected in 2003. Results from the field trials indicate that applying glyphosate in the spring was effective at reducing the biomass of crested wheatgrass for two seasons and shifting the dominance in the stands toward native or weedy species, depending on the plant and seedbank composition. Application of glyphosate increased diversity at sites with low initial diversity but not at sites with high initial diversity. Seeding was generally not successful, due primarily to lack of moisture and nitrogen. Switchgrass (Panicum mrgatum L.) and slender wheatgrass (Elymus trachycaulus (Link) Gould ex Shinners) were the most successful seeded species. Other native bunch grasses and forbs did not establish well. Because of the high cost of native seed and no-till drilling, this treatment is not recommended unless there is sufficient moisture and nutrients in the soil at the time of planting to support seedling growth.Item Taxonomic investigation of Erigeron lackschewitzii(Montana State University - Bozeman, College of Letters & Science, 1994) Kerstetter, TulliItem The sagebrush steppe of Montana and southeastern Idaho shows evidence of high native plant diversity, stability, and resistance to the detrimental effects of nonnative plant species(Montana State University - Bozeman, College of Agriculture, 2013) Quire, Ryan Lane; Chairperson, Graduate Committee: Matthew LavinThe premise of this study is that plant diversity is a neglected aspect of the North American sagebrush steppe, a once expansive biome that is now highly degraded. What kind of plant diversity is expected in the sagebrush steppe when it is not regularly physically disturbed? What ecological gradients most affect how plant diversity changes over large spatial scales? The answers to these questions could have implications for invasive plant management and the reclamation and restoration of the sagebrush steppe. Methods included sampling four regions of the sagebrush steppe in the northeastern portion of this biome. The Pryor Mountains, the Charles M. Russell National Wildlife Refuge, and the region of the Yellowstone Plateau were sampled in mostly Montana. These high-native-cover sagebrush sites were compared with those sampled in the Upper Snake River Plains region of southeastern Idaho. One hectare transects were established in high-native cover sagebrush steppe. These were paired with transects established in immediately adjacent disturbance-prone settings (e.g., roadsides) where sagebrush steppe vegetation remained intact. Geographically adjacent transects were sampled where they differed in at least one important ecological attribute. Key findings included that mountain big sagebrush steppe is evolutionarily distinct from Wyoming big sagebrush steppe and that the maximum temperature during the warmest month of the year was an important gradient for shaping species and phylogenetic beta diversity. Geographical proximity also had a large influence on the local species composition. The degree of disturbance also had less of an effect perhaps because of the influence of geography. The effects of physical disturbance were still detectable using descriptive approaches that compared infrequent with frequently disturbed transects. Regardless, native species diversity was distinctly diminished by physical disturbance, which is argued to be evidence that the sagebrush steppe is inherently ecologically stable. The implications of this research include the identification of specific taxonomic groups at and above the species level that may serve as benchmarks for sagebrush steppe reclamation or restoration. Long term stable conditions (infrequent disturbance regimes) are very much required for the successful restoration of the sagebrush steppe.Item Determining the suitability of native grasses for highway revegetation sod(Montana State University - Bozeman, College of Agriculture, 2007) Stott, Lance Vear; Chairperson, Graduate Committee: Tracy A.O. Dougher.In past years, the California Department of Transportation (Caltrans) has used hydroseeding, imprinting and drill seeding methods to revegetate highway construction sites with varying degrees of success. Ecological concerns have led researchers to consider using native species for revegetation as they are better suited to local environments, require less maintenance and do not pose a threat to adjacent ecosystems. In addition, the urgency for stabilizing areas of high erosion potential and that of establishing native plant cover quickly in order to prevent non-native plant and weed establishment, have led researchers to consider using native grass sod for highway revegetation. Twenty-one species of native grasses were selected in order to determine their suitability for sod production. Grasses were grown in six growth chambers; each mimicking one of the climates of the six selected California ecoregions. Mixtures of varying species included either one rhizomatous species with three bunch grasses, one rhizomatous species and five bunch grasses, two rhizomatous species with three bunch grasses, or two rhizomatous species with five bunch grasses.