Theses and Dissertations at Montana State University (MSU)
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Item Understanding the biology, ecology, and integrated managment of Ventenata dubia(Montana State University - Bozeman, College of Agriculture, 2019) Harvey, Audrey June; Chairperson, Graduate Committee: Jane M. Mangold; Lisa Rew, Timothy Prather and Jane Mangold were co-authors of the article, 'The effects of elevated temperature and CO 2 concentration on seedling growth of Ventenata dubia and Bromus tectorum' submitted to the journal 'Western North American naturalist' which is contained within this thesis.; Lisa Rew, Timothy Prather and Jane Mangold were co-authors of the article, 'Indaziflam provided up to three-years of control for Ventenata dubia in southwestern Montana' submitted to the journal 'Invasive plant science and management' which is contained within this thesis.; Stacy Davis, Lisa Rew, Timothy Prather and Jane Mangold were co-authors of the article, 'Effect of seeding date of Pseudoroegneria spicata (bluebunch wheatgrass) on establishment and subsequent ability to resist invasion by Bromus tectorum (cheatgrass)' submitted to the journal 'Ecological restoration' which is contained within this thesis.Ventenata dubia (Leers) Coss., common name ventenata or African wire grass, is a non-native winter annual grass of increasing concern in western Montana. In North American, V. dubia appeared in the early 1950s; since then it has successfully established in the northeastern and northwestern United States. It is known to invade areas previously inhabited by Bromus tectorum (cheatgrass) and Taeniatherum caput-medusae (medusahead). In the Intermountain Pacific Northwest, V. dubia has caused substantial ecological and economic impacts in perennial grass habitats. Varying disturbance regimes contribute to its rapid expansion over the last decade. Impending climate change threats have the potential to exacerbate the spread of this invasive species. Three independent studies were conducted to explore the biology, ecology, and integrated management of V. dubia populations in Montana to alleviate impacts by this species and other invasive annual grasses. A growth chamber study tested the effects of elevated carbon dioxide and temperature on seedling growth of V. dubia in response to climate change and in competition with B. tectorum. This competition replacement study indicated that at elevated climate conditions V. dubia and B. tectorum grow smaller and competition with V.dubia has the potential to decrease B. tectorum growth. A field-based herbicide efficacy trial utilizing the active ingredient indaziflam compared it to other commonly used herbicides to determine long-term control of V. dubia and potential plant community changes at 8, 11, 20, and 23 months after treatment. Foliar cover, species richness, and functional group biomass were collected. Findings indicated indaziflam can control V. dubia up to three years with positive implications for plant community dynamics. A revegetation study was used to determine the optimum seeding time for perennial grass species, Pseudoroegneria spicata, and the effects seeding time can have with competition dynamics with B. tectorum. A randomized complete block design was established and P. spicata grown for one season prior to Bromus tectorum seeding. After the second growing season, tillers and biomass were collected for both species. Findings indicated priority effects can occur with fall and early spring seeding of P. spicata, with implications for suppression of B. tectorum at earlier seeding dates.Item A Comparison of greenhouse methods as diagnostic tools for reclamation planning(Montana State University - Bozeman, College of Agriculture, 1984) Byron, Timothy MartinItem Soil retention capability of Deschampsia caespitosa, Phalaris arundinacea, and Poa pratensis upon exposure to flowing water(Montana State University - Bozeman, College of Agriculture, 1992) Strobel, Curt Calvin; Co-chairs, Graduate Committee: Clayton Blayne Marlow and Frank F. MunshowerItem Uptake and phytotoxicity of arsenic III and V in four grass species(Montana State University - Bozeman, College of Agriculture, 1995) Tice, Stephanie WagnerItem Availability of sulfur to alfalfa (Medicago sativa L.) and orchardgrass (Dactylis glomerata L.) as influenced by source and time of sulfur fertilizer applications(Montana State University - Bozeman, College of Agriculture, 1969) Stoltenberg, Larry EdwardItem Intraspecific differences in heavy metal accumulaton, distribution and uptake kinetics in the metallophyte, Deschampsia caespitosa(Montana State University - Bozeman, College of Agriculture, 1983) Cahoon, Richard StuartItem The establishment, drought tolerance, and weed suppression potential of multispecies sod(Montana State University - Bozeman, College of Agriculture, 2009) Stark, Jennifer Grace; Chairperson, Graduate Committee: Lisa J. Rew.Re-seeding is a frequently used technique to revegetate disturbed areas, but often leaves bare ground prone to weed invasion. Mixtures of drought tolerant or native species in sod could be used as an alternative to seed to provide rapid establishment of desirable plant communities that may potentially reduce weed emergence, survival, and productivity. Additionally, the reinforcement material required to aid transport of multispecies sod could further contribute to weed suppression and sod establishment. The objective of this study was to evaluate the weed suppression and establishment potential of multispecies sod. Three experiments were each subject to a water regime ranging from 2.54 cm of water/week to natural precipitation, and repeated over two/three years. In the first two experiments (A and B) Brassica napus (canola) was used as a surrogate weed species and sown either below the multispecies sod to represent weed seed bank, or above the multispecies sod to represent weed seed rain. In experiment A, B. napus was sown at six densities; while in experiment B reinforcement materials (nylon netting control, coconut-straw, jute, excelsior) were added below the sod and B. napus was sown at one density. B. napus suppression by multispecies sod, with or without reinforcement material, was evaluated by recording seedling emergence, survival and above-ground biomass. Multispecies sod, especially combined with reinforcement material, suppressed a large proportion of seedling emergence. The seedlings that did establish produced less vegetative and seed biomass as water decreased. In the second season of both experiments no seedlings survived to maturity. The establishment success of the multispecies sod was evaluated through repeated measures of percent sod cover over two/three years. The results suggested that the multispecies sod was able to establish and persist under natural precipitation. The third experiment evaluated the ability of multispecies sod to suppress Cirsium arvense (Canada thistle) vegetative propagules in two different habitat types, bare ground or multispecies sod, under high and low water treatments. More C. arvense shoots emerged in the bare ground, suggesting that multispecies sod could act as a buffer zone and reduce the vegetative spread of perennial weeds if used as a revegetation strategy.Item Impacts of native grasses and cheatgrass on Great Basin forb development(Montana State University - Bozeman, College of Agriculture, 2008) Parkinson, Hilary Ann; Chairperson, Graduate Committee: Catherine A. Zabinski.Land managers need more information on native forb growth and interactions between forbs and grasses to improve degraded sagebrush steppe habitats in the Great Basin, and to increase the diversity of revegetation seed mixes. This is especially important in areas infested with Bromus tectorum (cheatgrass), an annual grass present in more than 100 million acres of the Great Basin. To gather information on forb growth and measure the effects of both native grasses and B. tectorum on forbs, I conducted a greenhouse experiment with 5 native forbs: Lomatium sp., Eriogonum umbellatum, Machaeranthera canescens, Penstemon speciosus, Sphaeralcea munroana; two native grasses: Elymus elymoides and Poa sandbergii; and B. tectorum. Forbs were grown alone or with a grass, and were harvested after 6, 9 or 12 weeks of growth. Excluding Lomatium, which became dormant before week 12, forbs did not differ in shoot relative growth rate when growing alone, but the root relative growth rate of P. speciosus was 50% greater. Neither native grass reduced the biomass of any forb, but growth rate was reduced for two forbs. In contrast, B. tectorum reduced the biomass and growth rates of all forbs, between 50 and 96%. In a second experiment, to test the ability of native forbs to establish and grow with B. tectorum, 4 forb species were grown in plots seeded with densities ranging from 45-360 B. tectorum plants m -² at two locations in the Snake River Plain. Water content declined with increasing densities of B. tectorum and forb seedling survival was reduced for 2 species when B. tectorum densities were greater than 150 plants m -². Reductions in forb biomass greater than 90% occurred for three species when B. tectorum densities were less than 100 plants m-². This study demonstrated that sites with low expected densities of B. tectorum should be selected when seeding forbs, but that native forbs can establish in sites with B. tectorum densities less than 150 plants m -², that native grasses and forbs can be used together in seed mixes, and that phonological and morphological characteristics can be used to optimize the diversity of seed mixes.