Theses and Dissertations at Montana State University (MSU)
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Item Evaluating non-native annual brome control with herbicides and facilitating Wyoming big sagebrush establishment in degraded drylands(Montana State University - Bozeman, College of Agriculture, 2017) Metier, Emily Pierson; Chairperson, Graduate Committee: Lisa J. Rew; Matt Rinella (co-chair)The degradation of drylands, through resource extraction and non-native annual brome invasion, is a major problem throughout the Intermountain West. Most restoration relies on establishing desired species from seed, but success is limited and establishing Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) is especially failure prone. This study focused on developing methods for controlling annual bromes, specifically cheatgrass (Bromus tectorum L.) and Japanese brome (Bromus japonicus Thunb.), and successfully re-introducing native sagebrush steppe species to degraded drylands. In the greenhouse, I assessed the efficacy of glyphosate and four graminicides (clethodim, sethoxydim, fluazifop, and quizalofop) applied at two rates, to cheatgrass plants of different heights. I also assessed the same five herbicides on three accessions of cheatgrass and Japanese brome. All herbicides reduced cheatgrass biomass, with most effective control on plants less than 11 cm. Overall, glyphosate and sethoxydim treatments were least effective, and quizalofop and fluazifop treatments were most effective. Japanese brome and the disturbed accessions of both species were more susceptible to herbicides than cheatgrass and the undisturbed accessions. My field study targeted the same annual bromes on two Montana coal mines. Four herbicide treatments (control, glyphosate, quizalofop, or glyphosate plus quizalofop) and two seeding treatments (differing in the amount of sagebrush seed) were evaluated for their effectiveness to manage annual bromes and boost seeded species establishment. Half of each herbicide plot was retreated with quizalofop the second year. All herbicide treatments reduced annual brome cover, especially in plots that received glyphosate. Wyoming big sagebrush density and cover of sown species increased in seeded plots with and without herbicides, but there was no difference between seeding treatments. Herbicide effects on seeded species were inconsistent, though generally establishment was greatest in plots receiving glyphosate. Quizalofop retreatment reduced annual brome cover, but did not impact seeded species establishment. These results suggest that targeted herbicide applications can be used to control non-native annual bromes and increase seeded species establishment. Specifically, using glyphosate pre-seeding when plants are small and graminicides post-seeding, can decrease annual brome cover. These treatments can provide a window of opportunity for establishing species from seed, including Wyoming big sagebrush.Item The in vitro digestibility and utilization of Big Sagebrush and Black Sagebrush(Montana State University - Bozeman, College of Agriculture, 1985) Striby, Karl DavidItem An ecological investigation of moutain big sagebrush in the Gardiner basin(Montana State University - Bozeman, College of Agriculture, 1996) Hoffman, Trista LynnItem The influence of crude terpenoid constituents on mule deer preference for big sagebrush and black sagebrush(Montana State University - Bozeman, College of Agriculture, 1985) Personius, Timothy LeeItem The role of some environmental and man-made factors on big sagebrush (Artemisia tridentata Nutt.) reinvasion(Montana State University - Bozeman, College of Agriculture, 1972) Taha, Faisal KhidirItem Prediction of available forage production of big sagebrush(Montana State University - Bozeman, College of Agriculture, 1991) Creamer, William HenryItem Effects of Douglas fir establishment in southwestern Montana mountain big sagebrush communities(Montana State University - Bozeman, College of Agriculture, 1998) Grove, Adam JayItem A comparison of burned and unburned big sagebrush communities in southwest Montana(Montana State University - Bozeman, College of Agriculture, 1997) Walhof, Kendal ScottItem Food habits, range use and home range of pronghorn antelope in central Montana during winter(Montana State University - Bozeman, College of Letters & Science, 1967) Bayless, Stephen RoyA study of the food habits, range use, and home range of pronghorn antelope with emphasis on the winter period was conducted in 1966-67 on a 171,712 acre area in north-central Montana, The physiography and vegetation of the area was described. The vegetation consisted of eight types: sagebrush-grassland, grassland, shale slope, greasewood, greasewood-sage-brush, cropland, abandoned meadow, and woodland. Quantitative measurements of canopy coverage and densities of taxa were made for five of the eight types. Characteristics of the antelope population were evaluated from results of five aerial censuses in summer. There were 309 females per 100 males and 74 fawns per 100 females. Distribution of antelope and use of vegetation types was evaluated. The sagebrush-grassland type received most of the use, both in summer and winter. Most of the antelope observations in winter were in vegetation types where sagebrush was common. The average group size for antelope in winter was 23.5, with groups being largest when snow covered the ground. The average group size in summer was 9.4. Winter food habits were determined from the examination of 28 feeding sites and analysis of the contents of each of 18 rumen samples. The winter diet of antelope, determined by examination of feeding sites, consisted of 93 percent shrubs, 6 percent forbs, and a minor amount of grass. The diet determined by analysis of rumen contents consisted of 78 percent shrubs, 19 percent forbs, and a small amount of grass. Big sagebrush (Artemisia tridentata) provided the bulk of the antelope food. A statistical analysis was conducted to determine the relationship between abundance of available plant species and their significance in the diet of antelope. Big sagebrush was the only plant which was present in significantly higher proportions in the diet than in the plant community. Three dead fawns were found on the study area. The apparent cause of death was malnutrition. Their rumen contents did not vary significantly from those of other antelope collected during the winter. Poor body condition of antelope and fawn mortality was possibly related to quality of sagebrush in the diet. Winter home range size was determined for each of 16 individually marked antelope. Each of three was equipped with a radio transmitter. Marked antelope were located daily when possible, A total of 579 individual observations of marked antelope was recorded from December 10 through March 23. Eight of the marked antelope "shifted" their home range at least once in winter. A yearling female had a home range size of 5574.4 acres and a yearling male, 4l60.0 acres. Six adult females had an average home range size of 2841.4 acres; three fawn females, 2417.1 acres; and five fawn males, 1579.5 acres. Fawn females had the most variable home range size. Adult females used a larger area on the sagebrush-grassland vegetation type than on the grease-wood-sagebrush type. Both fawn males and females showed the opposite.Item 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.