Theses and Dissertations at Montana State University (MSU)

Permanent URI for this communityhttps://scholarworks.montana.edu/handle/1/732

Browse

Search Results

Now showing 1 - 10 of 13

The impact of recreational hunting of white-tailed deer on native and non-native plant abundance in northern pennsylvania
(Montana State University, 2020) Supplee, Heather; Chairperson, Graduate Committee: Anthony Slominski
The introduction and spread of non-native plant species is a large area of concern for land managers and ecologists, because these species are often capable of outcompeting native species, altering vegetative community dynamics by reducing species richness and ecosystem function. Low species diversity and disturbances in community structure are factors that may be associated with facilitating the success of non-native species. The white-tailed deer (Odocoileus virginianus) is a large herbivorous animal that can alter plant communities through a variety of mechanisms, including trampling and grazing. At high population densities, white-tailed deer can reduce plant species richness and alter plant community interactions, potentially facilitating an increase in the abundance and richness of non-native plants. Hunting is an effective tool for controlling high deer populations. In this study, I examined the impact of the presence or absence of recreational hunting on native and non-native plant species in habitats that were known to contain deer in north central Pennsylvania. I sampled native and non-native plant species richness and percent cover within 1m2 quadrats placed at 10 random locations along five transects. Two transects were in non-hunted, privately owned land and three transects were in public game lands. Each transect was sampled on five different dates, except for one transect in the private land, which was sampled four times. These transects represented a variety of habitat types. Plant species richness and percentage cover in hunted and non-hunted plots were analyzed with linear and generalized linear models using R statistical software. I found that native species richness was greater and non-native species abundance was higher at the public game lands compared to the site where hunting was prohibited. The greater native species richness in hunted sites suggests that controlling deer populations densities with hunting may play a role in maintaining the health of vegetative communities. Future studies should look at vegetative data in additional habitat types and survey sites across hunted and non-hunted lands to improve the certainty of these findings.
Water quality impacts from leaking coal ash ponds at two superfund sites
(Montana State University, 2020) Rozwara, Aeriel Kyra; Chairperson, Graduate Committee: Miranda Margetts
Coal is a fossil fuel used worldwide for energy production. Although coal is a plentiful and cost-efficient source of energy, the by-product of coal production, coal ash, poses environmental and human health risks. My analysis involved the identification and comparison of concentrations of thallium, manganese, and arsenic contamination at two Superfund managed sites that experienced a leak of coal ash ponds. I also examined the potential role that public awareness and risk management approaches undertaken at each site to contain the effect of the contamination may have played in mitigating the extent of the risk impacts. The Kingston Tennessee Valley Authority (TVA) coal ash spill received national media coverage and occurred over a large visible area in a relatively short time frame (December 2008 - December 2014). In contrast, the coal ash spill at Town of Pines received limited media attention and occurred slowly over many years (April 2000 - present). As a result, the spill remained unknown to many residents in neighboring counties. To investigate the efficacy of the implemented mitigation measures, I compared both the risk management approach to containing the spills, and the contaminant concentrations (arsenic, manganese, and thallium) at each site over time. Overall, the TVA coal ash spill received a relatively fast, intensive containment, reflected by contaminant values reduced to below EPA threshold levels within a matter of months. The visible extent of the spill was shared extensively by the media . Conversely, my analysis of the Town of Pines spill, which remained unknown to residents and received limited media attention, highlighted that although concentration values have decreased over a 15-year timeframe, some concentrations remain at harmful levels. The results of my study demonstrate the influence of public awareness and subsequent community pressure on the timeliness of remediation measures and reduction of overall environmental and human health risks from coal ash spills.
An ecological risk assessment of the establishment of the asian giant hornet (vespa mandarinia) in the pacific northwest
(Montana State University, 2020) Norderud, Erik D.; Chairperson, Graduate Committee: Robert K. D. Peterson
The recent introduction of the Asian giant hornet (Vespa mandarinia) in the United States in late 2019 has raised concerns about the establishment of the insect in the Pacific Northwest, and its potential deleterious effects to honey bees and their pollination services in the region. Therefore, I conducted a risk assessment to estimate the risk of establishment of V. mandarinia in Washington and Oregon on a county by county basis. To assess these risks, my assessment used the risk assessment framework put forth by the U.S. National Research Council. The risk assessment relied on the biological requirements and ecological relationships of V. mandarinia in the environments of the Pacific Northwest. I based the risk characterization on climate and habitat suitability estimates for V. mandarinia queens to overwinter and colonize nests, density and distribution of apiaries, and locations of major human-mediated introduction pathways that may increase the risk of establishment of the hornet in the counties of Washington and Oregon. My results suggest that 70 of the 75 counties in the region could be at medium to high risk of establishment by the hornet. Many of the western counties of both Washington and Oregon were estimated to be at the highest risk of establishment, mainly due to their suitable climate for queens to overwinter, dense forest biomass for nest colonization, and proximity to major port and freight hubs in the region. Considering its negative effects, these counties should be prioritized in ongoing monitoring and eradication efforts of the insect.
Timber harvest and topographic effects on the intermittency of headwater streams in western washington
(Montana State University, 2020) Bretherton, Welles David
Headwater streams make up the majority of the total stream length in the state of Washington. These non-fish-bearing upper reaches are critical habitat for sensitive stream-associated amphibian populations. During the low-flow summer months these streams contract and the surface flow that amphibian species rely on becomes disconnected from other flowing reaches, sometimes by hundreds of meters of dry channel. To understand these spatial and temporal shifts in the dry reaches of the headwaters, I used data that we collected as part of the Soft Rock study for the Washington State Department of Ecology. We measured the length of every dry reach in 11 non-fish-bearing watersheds, located in southwest Washington, for 8 years (2013-2020). In 2014 and 2015, a clearcut timber harvest treatment was implemented at 8 of the 11 basins. We used a generalized linear mixed model to test for a treatment effect on the percentage of the stream network that retained surface flow. In the first 2 years post-harvest, we found a 26% (post-1) then a 24% (post-2) increase in the Percent Wetted Channel (PWC) relative to the reference sites. In addition to treatment effects, we also tested for precipitation and topographic impacts on the PWC using a Pearson's R and a Random Forest model, respectively. Summer precipitation was correlated with PWC at the reference sites whereas annual precipitation was not. We also found synergistic effects with some of the topographic features. Smaller drainage area, low-gradient valleys, and steeper stream slopes were all associated with drier sections of the streams. All of these features are more likely to be found higher up in the watershed, so it is probable that a combination of this topography is increasing intermittency in the upper reaches of the headwaters of western Washington. This contraction and disconnection of surface flow at inconsistent spatial and temporal scales could create unreliable habitat for stream associated amphibians. Further research is needed on the habitat implications, and the potential for stream temperature increases due to the greater amount of surface flow post-harvest.
Linking substrate organic matter and water quality to invertebrate and fish populations within a constructed wetland treatment system
(Montana State University, 2020) Sees, Mark Daniel; Chairperson, Graduate Committee: William Kleindl
The Orlando Easterly Wetlands is a highly engineered and managed free surface flow constructed wetland treatment system that was constructed for the expressed purpose of removing nitrogen and phosphorus from municipal reclaimed wastewater. The system has been in operation since 1987 and is managed and maintained for water quality. Through the 33 years of operation, the system has accumulated tremendous amounts of organic matter through natural wetland processes. However, this organic matter has caused significant short-circuiting of water flow ultimately leading to the need for removal. Removal of the organics is expensive and time-consuming and results in a complete renovation of the wetland marshes. These renovation projects effectively remove the organics along with the plants and wildlife species that inhabit a given project area. My paper aims to link water quality, accreted organic matter, and wildlife diversity and abundance. I theorized that biodiversity within the system is influenced and driven by the constant input of dissolved nutrients and the associated organic matter accretion. Through substrate samplers, dip netting, and minnow traps, aquatic biota was sampled and correlated with water quality indicators such as chlorophyll-a, carbonaceous biochemical oxygen demand, ammonia, ortho phosphate, total kjedahl nitrogen, total nitrogen, and total phosphorus along with the depths of organic matter. The abundance of macroinvertebrates was strongly correlated with carbonaceous biochemical oxygen demand (r2=0.91) and total nitrogen (r2=0.88). Ammonia displayed a moderate positive correlation and depths of the accreted organic matter were weakly correlated. The presence and abundance of larger more mobile aquatic species were moderately correlated with levels of chlorophyll-a (r2=0.702). OP and TP showed significant negative correlations (r2 = -0.619, -0.628), respectively. Suggesting that as OP and TP concentrations decrease abundance increases. I also document the rapid recolonization of invertebrates within newly renovated marshes in the Orlando Easterly Wetlands and how this system provides outstanding biodiversity.
The relationship between yellow toadflax (linaria vulgaris) presence, treatment history, and plant species richness near west yellowstone, montana
(Montana State University, 2020) Williams, Amanda; Chairperson, Graduate Committee: Lisa Rew
Humans have spread plant species to novel ranges throughout history, but the rate of new introductions has drastically increased with globalization. These introduced species are often viewed as a threat to native species richness. Linaria vulgaris (yellow toadflax) was introduced to North America in the 1600s as a useful and ornamental plant and has since spread across the continent. It is mandated for control in much of the intermountain west and is thought to form monocultures to the detriment of native species. Despite L. vulgaris' long residence time on the continent, causal links to negative effects have not been established. Land managers are typically faced with a long list of species mandated for control and limited resources and thus must prioritize high impact species for control. Herbicide is the management choice for non-native plants in Yellowstone National Park, but it may have negative effects. Therefore, managers need to be sure that treatment is worthwhile, and that the effects of treatment do not exceed the effects of non-native plants. Consequently, I selected 10 sample sites in the West Yellowstone, Montana area: five with a recent history of herbicide treatment and five without. Data were collected on plant species richness and abundance within and immediately adjacent to L. vulgaris patches. Species richness and diversity did not vary between sites based on treatment history. Species diversity did increase where L. vulgaris was present, indicating that it may act as a "plus one" in communities and does not dominate where it occurs. Treatment history was not linked to a reduction in L. vulgaris abundance, but the abundance of other non-natives was greater in treated sites. These results indicate that land managers should not assume that L. vulgaris negatively effects native species richness and diversity in their location and should pair management efforts with rigorous monitoring. In the West Yellowstone area, L. vulgaris likely should not be a high priority for herbicide treatments. However, this study is observational and not sufficient to establish causal links.
The optimal consortia of microbial bioremediation agents for the removal of heavy metals from the superfund site at newtown creek in brooklyn, new york
(Montana State University, 2020) Korecki, Danielle Angela; Chairperson, Graduate Committee: Amaya Garcia-Costas
Bioremediation is a technique that introduces a microbial population capable of destroying, transforming, or immobilizing a pollutant of interest in a manner that is both safe to the environment and cost-effective. Bioremediation agents are effective in sequestering heavy metals, and are capable of functioning at their highest capacity when environmental conditions are complimentary to microbial growth, the indigenous microbial population favorably interacts with the introduced microorganisms, and nutritional requirements are satisfied either by the ecosystem or via the addition of amendments. Additionally, genetically engineered microorganisms can be utilized when necessary within especially challenging conditions. This study determines the ability of a consortia of microbial bioremediation agents to remove heavy metals from the Superfund site at Newtown Creek in Brooklyn, New York. The remediation of heavy metals at Newtown Creek can be accomplished using Rhodopseudomonas palustris, Saccharomyces cerevisiae, and Cupriavidus metallidurans. These microorganisms possess a high degree of potential and are promising tools in the reduction of Earth's ever-increasing pollution levels. Heavy metal concentrations, nutrient levels, pH, temperature, salinity, oxidation reduction potential, and the indigenous microbiome were analyzed to determine the expected benefit of microbial bioremediation in the reduction of heavy metal concentrations. Although high initial heavy metal concentrations and salinity may negatively impact this effort, all other variables are expected to be conducive to microbial growth. The introduction of amendments is expected to further benefit microbial bioremediation potential. The selected consortia of microorganisms introduced have the capacity to sequester all the chromium, lead, mercury, selenium, and silver found at Newtown Creek. The impact of arsenic, cadmium, copper, nickel, and zinc concentrations can also be decreased due to microbial bioremediation efforts. The use of genetically engineered microorganisms within a bioreactor is expected to further benefit remediation efforts for heavy metals sequestered at low rates within the natural environment. Microbial bioremediation is not expected to fully remove heavy metals from Newtown Creek, yet these microorganisms are capable of greatly improving conditions.
The ecological tradeoffs of invasive rhizophora mangle on the hawaiian islands
(Montana State University, 2020) Puklus, Kyla Patricia; Chairperson, Graduate Committee: Scott Powell
My research reevaluates historical nonnative mangrove eradication and habitat restoration goals on in Hawaii. As a part of this reevaluation, I establish a framework for weighing modern ecological services with negative ecological and socioeconomic costs. The purpose of my framework is to support land managers by providing updated assessments that accurately represent the contribution nonnative mangroves provide regarding Hawaii's current climate mitigation goals. This framework focuses on invasive Rhizophora mangle (red mangrove) stands as they are the most abundant type of mangrove on the islands. Recently published Rhizophora mangle carbon sequestration and soil accretion rates on the Hawaiian island of Molokai now allow us to estimate their ability to offset current greenhouse gas emissions and sea level rise rates. These offsets can then be weighed against the traditional view that all Rhizophora mangle must be removed. I estimate 4 km2 of ??. mangle currently sequesters 0.3% of Hawaii's current greenhouse gas reduction target and if removed would set this goal back by 8%. I also find that Rhizophora mangle vertically accretes sediment faster than current seal level rise and coastline erosion rates predicted for Hawaii, making this ecosystem service is a valuable asset in mitigating the effects of climate change. Historically, Rhizophora mangle removal is justified by a reduction in water quality and endemic bird habitat in both anthropogenic features like harbors, canals, and fishponds, and also sensitive coastline features like anchialine pools. By weighing the ecological impacts against services, I recommend strategic mangrove removal in sensitive areas and areas that hinder commerce. Mangrove removal efforts on the islands are currently active and on-going, financially supported by state and federal funding in conjunction with local conservation groups. I examine reported financial costs of previous mangrove removal projects and discuss the feasibility of island-wide eradication. Based on the cost of prior removal projects, I estimate the cost of full eradication above $41 million not including future monitoring and maintenance. With new climate mitigation goals being added to already burdened state and federal conservation and land management budgets, I promote a more pragmatic view of nonnative species by recommending strategic Rhizophora mangle management in lieu of full state-wide eradication.
Effectiveness of the pre-emergent herbicide indaziflam on the restoration of cheatgrass (bromus tectorum l.) infested rangelands in montana
(Montana State University, 2020) Hauptman, Ben Cameron; Chairperson, Graduate Committee: Jane M. Mangold
Cheatgrass (Bromus tectorum L.) is an invasive annual grass that was introduced to North America in the 1850s and is very abundant over 210,000 km2 in the western United States and is found in every Montana county. Cheatgrass encroachment negatively effects native vegetation in rangelands and results in losses of forage for livestock and wildlife, and its management is difficult. Therefore, the objective of this study was to determine if the use of indaziflam (Esplanade 200SC®) is an effective way to restore cheatgrass infested rangelands in Montana by decreasing cheatgrass abundance and increasing perennial grass abundance. The characteristics of indaziflam may provide an opportunity for rangeland managers to manage cheatgrass successfully. On ranches near Hall and Big Timber, Montana, I used a completely random design to compare vegetation in indaziflam treated plots and non-treated plots. Plots were sprayed in August 2018 with indaziflam using a CO2 powered handheld boom sprayer at a rate of 350 g/ha. Canopy cover and biomass of cheatgrass was reduced in the indaziflam treated plots at both sites. Canopy cover was 32.7% and 50.5% in non-treated plots and 0.55% and 0.80% in indaziflam-treated plots, cheatgrass biomass was reduced from 53.4 g/m2 and 82.2 g/m2 to 1.67 g/m2 and 2.8 g/m2. Perennial grasses responded to indaziflam treatments by producing more biomass, 204 g/m2 and 113.4 g/m2 in indaziflam treated plots compared to 74.2 g/m2 and 68.04 g/m2 in non-treated plots. Canopy cover in indaziflam treated plots was not different compared to non-treated plots. Annual forb canopy cover and biomass was also reduced in the treated plots and were nearly absent following indaziflam applications. Perennial forb abundance was not different between plots that had been treated and the non-treated plots. Indaziflam effectively controlled cheatgrass at both sites. Increases in forage production indicate perennial grasses were more vigorous following the reduction of cheatgrass. Livestock producers would expect an increase in animal units per month (AUMs)/acre on rangelands treated with indaziflam, but grazing management and the cost of herbicide application indicate more long-term research is needed to determine if this would be an economically viable option for land managers.
The effect of urbanization on stream-flow patterns on big creek watershed, alpharetta, georgia
(Montana State University, 2020) Avila, Iris; Chairperson, Graduate Committee: Paul Hook
The natural flow regime, defined as the characteristic pattern of discharge variation in streams and rivers not altered by humans, plays an important role in the ecosystem. The increase in urban development in the U.S. is an important environmental change that alters the landscape and affects the flow regime of streams and rivers. Previous hydrological studies have used different methods to investigate the effects of urbanization on stream flow; these studies have found that urbanization can often lead to an increase in peak flow (largest instantaneous magnitude occurring in a water year), increased flashiness (rapid change in magnitude), and reduced baseflow (relatively steady stream-flow primarily maintained by groundwater between storm runoff events). With increasing urbanization in the southern U.S., my study focused on Big Creek watershed, located in one of the most populated cities, Metro-Atlanta. Several studies have investigated urbanization effects on stream-flow in Metro-Atlanta, but these studies have focused on the Peachtree Creek watershed, a highly urbanized watershed located near downtown Atlanta. In contrast, the Big Creek watershed is a less intensively developed area about 20-35 miles from downtown Atlanta. I used a paired watershed approach with a nearly 60-year period of record to characterize Big Creek discharge before and after urban development and to compare changes in Big Creek to a non-urban reference watershed, Snake Creek. Several hydrological trend analyses and pre- versus post-urbanization comparisons revealed that urbanization altered some features of the flow regime. The post-urban period in Big Creek resulted in an 11% increase in high flow (defined as 5% annual exceedance probability), 25% decrease in low flow (90% annual exceedance probability), 27% decrease in average peak flow, 14% decrease in average baseflow, and a flashier discharge. Current stormwater management strategies within Big Creek target minimizing peak flow events by requiring facilities to control for the 2-year to 100-year flood event. The findings indicate that stormwater management strategies should also aim to restore baseflow and reduce flashiness within the watershed.

Theses and Dissertations at Montana State University (MSU)

Browse

Filters

Settings

Sort By

Results per page

Search Results