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20th Century Forest-GrassLand Ecotone Shift and Effects of Livestock Herbivory: Author: Sankey, Temuulen Tsagaan; Date: 2005-12-15; Program: Land Resources and Environmental Sciences; Abstract: I studied 20th Century lower forest-grassLand ecotone shift in the Centennial Valley in southwestern Montana, USA and the Darhad Valley in northern Mongolia and investigated the effects of livestock herbivory on ecotone dynamics. A total of 525 aspen (Populus tremuloides) and 1,703 Douglas-fir (Pseudotsuga menziesii) trees were cored and 10,168 seedlings were counted at five sites along the ecotone in the Centennial Valley. A total of 2,968 Siberian larch (Larix sibirica) were cored and 4,709 seedlings were counted at five ecotones in the Darhad Valley. Tree-age distribution was constructed to...; Download File | View full details

Assessing Constructed WetLands for Beneficial Use of Saline-Sodic Water: Author: Kirkpatrick, Amber Denise; Date: 2005-05-15; Program: Land Resources and Environmental Sciences; Abstract: Changes in agricultural practices, and irrigation strategies combined with natural processes, have led to increased salinization of soil and water Resources worldwide. Coal bed methane (CBM) development in the Powder River Basin of Montana and Wyoming results in the co-production of large volumes of sodic and moderately saline discharge water, and represents a potential source of salinization of soil and water Resources. The objective of this study was to evaluate the potential of constructed wetLands as a tool for CBM product water management. This was accomplished by assessing seasonal water...; Download File | View full details

Belowground Competition and Response to Defoliation of Centaurea maculosa and Two Native Grasses: Author: Sartor, Karla Anne; Date: 2005-08-15; Program: Land Resources and Environmental Sciences; Abstract: Invasion of native rangeLands in the western United States has serious ecological and economic effects. Understanding the mechanisms behind invasion of Centaurea maculosa (spotted knapweed) is necessary to effectively manage this species. Arbuscular mycorrhizae (AM), which are a type of plant fungal symbiosis, are ubiquitous in grassLands. My research explores the role of AM for increasing the competitive ability of C. maculosa. A greenhouse experiment tested the effects of AM fungi and neighbor species growth of C. maculosa, Festuca idahoensis (Idaho fescue) and Pseudoroegneria spicata (blueb...; Download File | View full details

Comparative Nitrogen Partitioning and Water use by Native and Introduced Grass Communities in Southern Alberta, Canada: Author: Porter, Shane Warren; Date: 2005-12-15; Program: Land Resources and Environmental Sciences; Abstract: The objectives of this research were to evaluate 1) short-term changes in soil and plant N partitioning created by cultivating and re-seeding native grassLands with two cropping systems of wheat and perennial (crested wheatgrass and Russian wildrye) monocultures; 2) differences in the rate of soil water uptake between Mixed Prairie grassLands, crested wheatgrass and Russian wildrye after a dry-down period; and 3) differences in above ground water use efficiencies, root and crown masses between Mixed Prairie grassLands, crested wheatgrass and Russian wildrye under two different soil water conte...; Download File | View full details

Enhancing Native Forb Establishment and Persistance using a Rich Seed Mixture: Author: Half, Melissa Lindsey; Date: 2004-05-15; Program: Land Resources and Environmental Sciences; Abstract: Introducing and establishing desirable competitive forbs is crucial for successful invasive plant management and the re-establishment of a desirable plant community. The objectives of this study were: 1) To measure germination, dormancy, and viability of six native forbs, 2) To determine whether increasing forb seeding rate will yield an increase in forb establishment, 3) To examine the effects of a species mixture versus a single species on establishment and survival of desired species, and 4) To determine whether a mixture or a monoculture of forbs is more competitive with spotted knapweed. ...; Download File | View full details

Evaluating and Monitoring Invasive Plant Processes: Author: Repath, Charles Fitts; Date: 2005-05-15; Program: Land Resources and Environmental Sciences; Abstract: Non-indigenous plant species (NIS) are a concern for both natural area Land managers and the public. These species are perceived negatively despite the fact that the processes and impacts related to NIS are not fully understood. Also, control is generally conducted without understanding NIS population ecology. As a result, few NIS populations have been successfully controlled. We studied the population ecology of NIS in natural areas. First, Linaria vulgaris was monitored at different spatial scales over three years to determine its invasiveness, and also to determine which life history states...; Download File | View full details

Influence of Native Bunchgrass and Invasive Forb Litter on Plant Growth in a Semi-Arid Bunchgrass Prairie: Author: Hoopes, Carla; Date: 2006-05-15; Program: Land Resources and Environmental Sciences; Abstract: Litter can influence plant species diversity. I investigated plant litter effects for density, cover, and biomass on common St. Johnswort Hypericum perforatum L., a nonnative- species-group, and a native-species-group. The following hypotheses were tested: litter source would favor species dominant in the litter; the high amount of litter (908 grams) would decrease density more than the moderate amount (454 grams); coarse size litter would decrease density more than fine size; and the effect of litter would depend upon interactions of all three variables. Above-ground plant material was remove...; Download File | View full details

Mapping and Change Detection of WetLand and Riparian Ecosystems in the Gallatin Valley, Montana using Landsat Imagery: Author: Baker, Corey Ryan; Date: 2004-12-15; Program: Land Resources and Environmental Sciences; Abstract: The location and distribution of wetLands and riparian zones influences the ecological functions present on a Landscape. Accurate and easily reproducible Landcover maps enable monitoring of Land management decisions and ultimately a greater understanding of Landscape ecology. Multi-season Landsat ETM+ imagery from 2001 combined with ancillary topographic and soils data was used to map wetLand and riparian systems in the Gallatin Valley of Southwest Montana. Classification Tree Analysis (CTA) and Stochastic Gradient Boosting (SGB) decision-tree based classification algorithms were used to disti...; Download File | View full details

The Population Dynamics of Tansy Ragwort (Senecio jacobaea) in Northwestern Montana: Author: Bauer, Brad David; Date: 2006-05-15; Program: Land Resources and Environmental Sciences; Abstract: Following the Little Wolf wildfire of 1994 in northwestern Montana, tansy ragwort (Senecio jacobaea) was classified as a state noxious weed. This project aimed to help prioritize the management of populations of tansy ragwort through an understanding of the biotic and abiotic factors influencing the species. Using field collected data and by constructing a prediction model, we found that the most important variables to predict the presence of tansy ragwort were distance from the main road, slope, cosine of aspect, and several remotely sensed LandSAT ETM+ bands. Most of the predicted occurrence...; Download File | View full details

Soil Water Flow and Irrigated Soil Water Balance in Response to Powder River Basin Coalbed Methane Product Water: Author: Buchanan, Margaret MacNeill; Date: 2005-05-15; Program: Land Resources and Environmental Sciences; Abstract: A repacked soil columns experiment and a series of computer soil water balance simulations were conducted to examine potential impacts of coalbed methane (CBM) water from Montana's Powder River Basin (PRB) on soil water flow and water balance in PRB soils. CBM water is often high in sodium, which may separate soil clay particles, particularly after soil exposure to low-salinity rainfall or snowmelt, and when soils contain expansible smectite clay minerals. Aggregates in soils exposed to sodic water may swell and slake, and clays and other fine particles may disperse, clogging soil pores and sl...; Download File | View full details

Soil Water Use and Root System Characteristics of C. maculosa and Sympatric Plants: Author: Swan, Megan Cashman; Date: 2004-08-15; Program: Land Resources and Environmental Sciences; Abstract: Centaurea maculosa Lam. (spotted knapweed) is an introduced perennial forb that invades disturbed and undisturbed semiarid grassLands in the western United States. It forms dense monocultures and reduces native and desirable vegetation. We hypothesized that C. maculosa may succeed through a superior ability to access soil water. This study had two objectives, to compare soil water uptake patterns under C. maculosa, perennial grass, and R. hirta monocultures in the field on semiarid rangeLand, and to compare root characteristics of C. maculosa and R. hirta plants grown under two soil water regi...; Download File | View full details

Stream-Groundwater Interactions in a Mountain to Valley Transition: Impacts on Watershed Hydrologic Response and Stream Water Chemistry: Author: Covino, Timothy Patrick; Date: 2005-12-15; Program: Land Resources and Environmental Sciences; Abstract: As mountain headwater catchments increase in size to the meso-scale, they incorporate new Landscape elements including mountain-valley transition zones. Mountain-valley transition zones form part of the mountain front, influence groundwater (GW)-stream interactions, and impact hydrologic response and stream water composition. Mountain front recharge (MFR) in mountain-valley transition zones and subsequent GW discharge to streams in the valley bottom are important hydrological processes. These GW-stream interactions are dynamic in both space and time, playing a key role in regulating the amount...; Download File | View full details

Temporal and Spatial Patterns at Alpine Treeline in the Sierra Nevada USA: Implications for Global Change: Author: Bunn, andrew Godard; Date: 2004-08-15; Program: Land Resources and Environmental Sciences; Abstract: This work focuses on developing understanding of the role of climate variability in shaping montane Landscapes. Due to the temperature-related stresses on treeline populations it is thought that change at treeline is an indicator of global warming. Interpretation of treeline changes has been hampered by issues of scale and the paucity of Landscape-scale data. The application of remotely sensed imagery and computer-based mapping programs has filled this gap with datasets that have large extents and fine spatial grain. I used geospatial information about treeline in concert with population and p...; Download File | View full details

Vegetation Dynamics in Yellowstone's Northern Range: 1985-1999: Author: Savage, Shannon Lea; Date: 2005-12-15; Program: Land Resources and Environmental Sciences; Abstract: The Northern Range (NR) of Yellowstone National Park (YNP) is currently a critical area of analysis in the Greater Yellowstone Ecosystem (GYE). The complex dynamic ecosystems in the NR provide outstanding field laboratories for long-term scientific investigations to evaluate management techniques. GrassLand and shrubLand ecosystems serve as important habitat for a wide variety of animal species in the NR and empirical knowledge of these systems enables managers to better understand the ecological complexities and make informed management decisions. Accurate vegetation maps are useful tools for...; Download File | View full details

Water Use Potential and Salt Tolerance of Riparian Species in Saline-Sodic Environments: Author: Sessoms, Holly Nicol; Date: 2004-08-15; Program: Land Resources and Environmental Sciences; Abstract: Salinization of soil and water Resources exists on a global scale, largely due to irrigated agriculture in semi-arid climates. Coal bed methane (CBM) development, resulting in the co-production of saline-sodic discharge water, is a potential new source of salinzation in the Powder River Basin of Montana and Wyoming. Constructed wetLands may serve to reduce CBM product water volumes while applying saline-sodic product water to a beneficial use. The objective of this study was to assess the potential of constructed wetLands as a new management tool for CBM product water management. To accomplish...; Download File | View full details

Wheat Yield Prediction Modeling for Localized Optimization of Fertilizer and Herbicide Application: Author: Wagner, Nicole Catherine; Date: 2004-08-15; Program: Land Resources and Environmental Sciences; Abstract: The specific goal of this thesis was the development of a five-variable dryLand wheat yield prediction model for the optimal localized variable-rate management of fertilizer and herbicide considering varying levels of available water and weed infestation. The motivation for this work was to increase on-farm net return and reduce off-target chemical effects. The five most influential predictor variables of wheat yield were investigated: wheat density, wild oat density, nitrogen fertilizer rate, herbicide rate, and water level Previously collected field data sets that included dryLand wheat yiel...; Download File | View full details

Toadflax, Fire, Mecinus Janthinus, and Compensatory Growth: Author: Anthony, Antoinette; Date: 2005-08-15; Program: Land Resources and Environmental Sciences; Abstract: Dalmatian toadflax is a noxious weed of the western United States. In western Montana it invades in the foothills zone where bunchgrasses (Agropyron spicatum and Festuca idahoensis) meet low forests (Pinus ponderosa and Pseudosuga menziesii). Our results show that wildfire strengthens toadflax, probably at the expense of native grasses. The stem boring weevil, Mecinus janthinus, is being tested as the most likely biocontrol agent for the weed. On our toadflax infested sites in the Agropyron spicatum/Pinus ponderosa zone Mecinus established, survived, and spread slowly (2-4m/yr) for two years f...; Download File | View full details

Diffuse Reflectance Spectroscopy for the Characterization of Calcareous Glacial Till Soils from North Central Montana: Author: Steward, Genevieve Christine; Date: 2006-12-15; Program: Land Resources and Environmental Sciences; Abstract: Diffuse reflective spectroscopy (DRS) is a method of soil carbon (C) quantification. In this study, the Vis-NIR (350-2500 nm) and MIR (2500-25000 nm) regions were evaluated to determine respective predictive accuracies of soil organic and inorganic carbon (SOC and SIC, respectively). The dataset included 315 soil samples of glacial till origin, obtained from six independent farm sites within the Golden Triangle region of Montana, with depths ranging from 0-100 cm. For Vis-NIR analysis, Local vs. Regional vs. Global calibration sets were compared by six-fold cross validation by site of C predic...; Download File | View full details

Climate Variability and Treeline Dynamics in Yellowstone and Grand Teton National Parks: Author: Schrag, Anne Michelle; Date: 2006-12-15; Program: Land Resources and Environmental Sciences; Abstract: Understanding the impacts of climate variability on high-elevation forests is of great importance due to the interest in upper treeline as an indicator of future change in protected mountain systems. While the location of upper treeline is primarily controlled by temperature, investigation of local treeline processes reveals considerable complexity in the spatial and temporal responses of species to various climatic parameters. The focus of the work presented in this thesis is to increase the understanding of the bioclimatic drivers of upper treeline species distribution and abundance in Yello...; Download File | View full details

Arbuscular Mycorrhizae in Yellowstone National Park Thermal Soils: Host Plant, Fungal Inoculum, Soil pH, and Elevated Temperature Effects on Symbiosis Function: Author: Bunn, Rebecca Anne; Date: 2004-08-15; Program: Land Resources and Environmental Sciences; Abstract: Arbuscular mycorrhizae (AM) are frequently described as a textbook example of a mutualistic symbiosis between a plant and fungus. However, we now understand that AM fungi are not always beneficial to their host plants. By requiring host plant photosynthate in exchange for potential benefits, the symbiosis varies along a continuum from mutualistic to parasitic. Examining AM function in extreme environments may increase our understanding of how the balance between symbionts is achieved, and if it is altered in the presence of strong abiotic stresses. Thermal soils offer a unique opportunity to s...; Download File | View full details

Microbial Ecology of an Antarctic Subglacial Environment: Author: Mikucki, Jill Ann; Date: 2005-12-15; Program: Land Resources and Environmental Sciences; Abstract: The research presented in this dissertation focused on the microbial ecology of the subglacial discharge from the Taylor Glacier in the McMurdo Dry Valleys, Antarctica. The major objectives of my research were to 1) define the biogeochemistry of the subglacial outflow 2) describe the microbial diversity of the subglacial outflow and 3) examine the impact of subglacial outflow on the geochemistry and biology of the west lobe of Lake Bonney, a lake that abuts the glacier. The subglacial outflow from the Taylor Glacier is known as Blood Falls owing to a visible accumulation of iron-oxides at the ...; Download File | View full details

Plant-Metal Interactions in a Natural and Remediated High Elevation Metal-Contaminated WetLand: Author: Olsen, Lois Jeanne; Date: 2004-05-15; Program: Land Resources and Environmental Sciences; Abstract: WetLands and riparian areas, critical habitats for both species and Landscape diversity, were often the sites of hard rock mining beginning in the late 19th century. Mining created heavy metal-contaminated wastes associated with ore bodies and mine tailings, and acid mine drainage. The Ontario Mine, in west central Montana, was remediated in 2002 by removing bare tailings piles, which were replaced with clean soil, and seeded and planted with native species. Tailings in the Ontario mine wetLand that had naturally revegetated were left in place, and there was no treatment of adit water draining...; Download File | View full details

Long-Term Perspectives on Northern Rockies Climatic Variability from Tree Rings in Glacier National Park, Montana: Author: Pederson, Gregory Thomas; Date: 2004-05-15; Program: Land Resources and Environmental Sciences; Abstract: Instrumental climate records reveal fluctuations in summer moisture anomalies and winter snowpack in Glacier National Park, Montana, on decadal and multidecadal timescales. However, because climate records for the region are limited to the 20th century, studies on the impacts of long-duration variations in climate on physical and ecosystem processes were limited. Therefore, a reconstruction of summer moisture variability (June - August) spanning A.D. 1540-2000 was created from a multi-species network of tree-ring chronologies sampled in Glacier National Park. The reconstruction shows decadal-s...; Download File | View full details

Temperature and Light Adaptations of Synechococcus Isolates from a Hot Spring Microbial Community: Author: Allewalt, Jessica Post; Date: 2004-12-15; Program: Land Resources and Environmental Sciences; Abstract: Previous molecular analysis of a well-studied microbial mat system in Yellowstone National Park revealed numerous genetically distinct 16S rRNA sequences distantly related to the 16S rRNA sequence of the unicellular cyanobacterium Synechococcus lividus. These new genotypes were shown to be contributed by the predominant cyanobacterial populations. Patterns in genotype distribution relative to temperature and light conditions suggested that these populations may have evolved through adaptive radiation to fill ecological niches. In order to test this hypothesis, Synechococcus isolates were culti...; Download File | View full details

Using Ecological Theory to Guide the Implementation of Augmentative Restoration: Author: Bard, Erin Christina; Date: 2004-05-15; Program: Land Resources and Environmental Sciences; Abstract: Invasive organisms are now considered the second worst threat to native biological biodiversity, behind habitat loss and fragmentation. Successful control of invasive plants can have unexpected impacts on native plants and wildLand systems. Therefore, it is important for managers of invasive species to become increasingly concerned with more than target invaders, but also ecological mechanisms and processes like invasion resistance, Environmental heterogeneity, and succession that direct plant community dynamics. Augmentative restoration is a management approach that augments existing ecologic...; Download File | View full details

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