Theses and Dissertations at Montana State University (MSU)
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Item 'Hypertemporal' remote sensing of plant function: a comparison of phenocam and geostationary operational environmental satellite NDVI data products(Montana State University - Bozeman, College of Agriculture, 2019) Douglas, James Thomas; Chairperson, Graduate Committee: Paul C. StoyOngoing climate warming is changing the seasonality of plant canopy function, but common approaches to explore these changes via polar-orbiting satellites often miss rapid canopy transitions due to infrequent observations. I explored the ability of satellites designed for studying weather systems, namely The Geostationary Operational Environmental Satellite (GOES), to track plant canopy status on time scales of minutes. With new capabilities to remotely sense in the infrared, the GOES weather satellites now have the capability to detect photosynthetic activity. Satellite observations of the normalized difference vegetation index (NDVI) are compared against near-surface phenological camera ("PhenoCam") observations from the National Ecological Observation Network (NEON, Inc.) at six sites every 15 minutes for one week in April 2019. Diurnal trends across both observation platforms showed the expected diurnal parabolic structure in NDVI with critical differences in NDVI magnitude between PhenoCams and GOES observations. One tailed T-test results show that there is variability between methods when measuring NDVI, with P-values less than 0.05 in all cases. This was anticipated due to correction factors needed for PhenoCam NDVI observations. However, additional variability can be attributed to other areas such as cloud cover, plant type, and heterogeneity. My proof-of-concept study demonstrates that raw NDVI data from both methods are often comparable, which lends credit to the notion that NDVI can be accurately observed from space at high (up to five minute) temporal resolution. With current research underway on the topics of atmospheric corrections and further surface validation, GOES has the potential to observe land surface attributes at up to 5-minute intervals across entire hemispheres for identifying phenology, disturbance and other vegetation dynamics in real time. With two hypertemporal methods at different spatial scales recently introduced, the research is primed to move towards a real time understanding of plant canopy function across the United States.Item The role of canopy tree diversity on understory plant richness and tree seedling abundance in a Pinus strobus forest in the southeastern U.S.(Montana State University - Bozeman, College of Agriculture, 2019) Davis, Stephanie Ann Morrow; Chairperson, Graduate Committee: Lisa RewThe goal of my project was to determine whether diversity in the canopy layer of a Pinus strobus dominated, mixed mesic forest in the piedmont of North Carolina showed a relationship to 1) understory richness and 2) tree seedling abundance. Forty plots were randomly selected at White Pines Nature Preserve, in Sanford, North Carolina for the study. For each plot, understory, species and tree seedling richness and density were recorded. Explanatory variables included canopy tree species richness, density and cover, total diameter at breast height (dbh) and environmental data including soil type, distance to nearest trail, and elevation. Diversity was calculated using the Simpson Index of Diversity (1-D) to show the effect of dominance in the canopy. Understory richness showed a decreasing pattern with increasing canopy diversity (p= 0.0783), suggesting a negative effect of canopy diversity on understory richness. Likewise, tree seedling abundance showed a significant negative response to canopy richness (p= 0.0146) and to all soils types (both positive and negative response). Total canopy tree basal area (diameter of tree at breast height) showed a positive relationship (p= 0.0514) to canopy species diversity (with functional similarity), which supports research showing complementarity between functionally-similar canopy tree species. Overall, results for this study suggest that, in a historically Pinus strobus-dominated forest, although greater canopy tree basal area is related to higher canopy diversity, understory richness is negatively affected by higher canopy diversity, and tree seedling abundance is negatively affected by higher canopy species richness.Item Spatial analysis of the recovery of submerged aquatic vegetation in the Hudson river estuary following the 2011-2012 hurricane seasons(Montana State University - Bozeman, College of Agriculture, 2019) Carroll, Sean Michael; Chairperson, Graduate Committee: Scott PowellSubmerged aquatic vegetation (SAV) is a critical habitat found in estuarine ecosystems throughout the world. SAV performs a multitude of ecosystem functions ranging from water quality improvement to habitat for macroinvertebrates and juvenile fish, and acts as a significant contributor to dissolved oxygen throughout the estuarine system. In the Hudson River Estuary (HRE), native SAV beds have been greatly reduced or altered by threats such as sedimentation, water quality issues, and the spread of invasive aquatic plants, as well as by disturbance from natural events such as large-scale storms. In 2011 and 2012, three hurricanes made landfall in the northeastern United States, having a tremendous impact on the Hudson River and the Hudson Valley region as a whole. SAV in the estuary was impacted by both storm surge as well as significant sediment deposition from the river's tributaries. However, in the wake of these events, there is uncertainty about the spatial patterns of SAV loss and recovery, and how these patterns are affected by the hydrology and physical characteristics of the river. Therefore, my study seeks to address this knowledge gap by investigating the impacts of these storms on SAV spatial patterns and the influence of SAV proximity to shoreline, tidal wetlands, and persistent "colony" SAV beds. I investigated these effects by analyzing overall (whole system) SAV recovery, the spatial patterns of recovery, and the correlation of recovery to prior SAV coverage and proximity to these features. Analysis was done using three years of remotely-sensed SAV GIS data, and was done at three different spatial scales. SAV coverages were determined at each scale for all three years and areal-change and percentage-change were calculated. Distance to the three aforementioned features was calculated for the fine-scale analysis. The results suggest that there was significant SAV loss river-wide between 2007 and 2014, followed by significant recovery between 2014 and 2016. Loss between 2007 and 2014 was greatest in the most upstream approximately 100 km of the river, likely a result of proximity to the Mohawk River, a major tributary and large sediment source during the storms. SAV recovery showed a similar pattern, occurring most in these upstream reaches. Distance from shoreline, tidal wetlands, and persistent SAV beds had varying impacts on SAV loss and recovery. The findings of this study help to elucidate both the potential impacts on the magnitude and patterns of vegetation loss following a large storm event and subsequent sediment flux, as well as the recovery potential of this vegetation during 'normal' years. Such information can help inform future biological studies of the HRE and watershed management decision-making.Item Water quality and physical parameters of Barnegat Bay after Hurricane Sandy(Montana State University - Bozeman, College of Agriculture, 2019) Rodenberg, Taylor; Chairperson, Graduate Committee: William KleindlBarnegat Bay is a coastal water body located off of the east coast of New Jersey. The bay is bordered by an estuary system to the west and barrier island and the Atlantic Ocean to the east. The bay is an important ecosystem for dozens of species of invertebrates, fish, mammals, birds, and amphibians, and provides millions of dollars in revenue for surrounding towns in tourism and recreation. However, coastal water bodies such as Barnegat Bay are subject to impacts from coastal storm systems such as hurricanes and tropical storms. My assessment determined how physical water properties and chemistry including water temperature, dissolved oxygen, pH, salinity, turbidity, specific conductance, and chlorophyll A were affected during landfall of Hurricane Sandy on October 29, 2012. Data on these properties was collected from available sources and were analyzed for significance in year-long data before and after hurricane landfall as well as one week before and after landfall in 2012 as compared with 2013. Results suggest that significant changes in water temperature, dissolved oxygen, pH, turbidity and chlorophyll a were observed in the week before compared with after the hurricane, while only significant changes in pH, turbidity and chlorophyll a could be observed in the year-long analysis. These data could be used to encourage further research in impacts to bay systems from coastal storms and to help create restoration plans following a storm system or preventive measures to ensure the health of the bay after major storms.Item Evaluating growth-defense trade-offs in ponderosa pine (Pinus ponderosa) in response to stimulated bark beetle attack(Montana State University - Bozeman, College of Agriculture, 2019) Hull-Jones, Jessica Wrae; Chairperson, Graduate Committee: Amy TrowbridgeThe mountain pine beetle (MPB; Dentroctonus ponderosae, Hopkins, Coleoptera: Curculionidae: Scolytinae) and its associated blue stain fungi are considered to be among the greatest natural threat to conifer ecosystems worldwide. In response to a rapidly changing climate, namely more frequent and hotter droughts, bark beetles benefit through a combination of higher reproductive capacity and greater availability of weakened and stressed host trees. Conifers have potent constitutive and induced chemical defenses to resist the bark beetle-fungi complex, but investment in these carbon-based defenses may be constrained by trade-offs associated with a tree's inherent growth rate. Although there are trade-offs that exist among all processes, it is unclear whether those particular growth-defense trade-offs are measurable and can be compared between individuals within various populations. Here we assess the concentration and composition of constitutive and induced terpene chemical defenses as a function of intraspecific variation in growth rates (slow-versus fast-growing mature ponderosa pines). We examine these relationships in the context of classical plant defense theories as well as the current state of the field. By determining the variation in chemical responses to stimulated bark beetle attack we can further our understanding of potential resistance trade-offs that might exist in stands that are being selectively bred for fast growth.Item Dynamics of native desert shrubs at restoration plots in the southern San Joaquin Valley, California(Montana State University - Bozeman, College of Agriculture, 2019) Peppel, Landon Charles; Chairperson, Graduate Committee: Scott PowellMy study relied on data accumulated over multiple recent years for shrub restoration at Wind Wolves Preserve, a 37,635 ha nature preserve located in the Southern San Joaquin Valley, California. Shrub species selected for the restoration project focused on creating habitat for threatened and endangered species such as San Joaquin kit fox (Vulpes macrotis mutica), Western burrowing owl (Athene cunicularia hypugea), and blunt-nosed leopard lizard (Gambelia sila). Monitoring data from 541 individual plants across 8 different species and different height classes were examined for survival after the initial planting date. Analysis of variance (ANOVA) was used to compare the relationship to survival and individual shrub species and their heights at planting. Results indicate that certain shrub species survived more frequently than others (p < 0.0001). Plants also varied by height at the original planting date (p = 0.001); however, plant height did not significantly affect dead or alive status (p = 0.76). The results of this study have implications for management decisions for San Joaquin Valley shrub restoration on retired agricultural lands suitable for threatened and endangered species habitat restoration. Future studies might examine more closely the significance of planting date, and the use of other restoration techniques, such as inoculation of arbuscular mycorrhizal fungi.Item Effects of road construction on water quality parameters and bull trout (Salvelinus confluentus) populations in three Montana water bodies(Montana State University - Bozeman, College of Agriculture, 2019) Thatcher, Hannah Alicen; Chairperson, Graduate Committee: Scott PowellRoad construction adjacent to rivers and ensuing clearing of timber and shrubs can lead to alterations in the dynamics and morphology of channel features and water chemistry that provide habitats for aquatic biota. We examined associations between bull trout (Salvelinus confluentus) populations and water quality parameters related to road construction in three western Montana rivers over a 15-year study period. Bull trout have specific habitat requirements that can influence their overall abundance and distribution within a watershed, making them an important indicator species of general ecosystem health. We used average annual bull trout population data from Montana Fish, Wildlife, and Parks and daily water quality observations from the United States Geological Survey between 2000 and 2014 to analyze the correlation between the data sets. We used a nonparametric statistical test to determine whether any significant change was observed between the medians of pre- and post-construction water quality parameters and bull trout population numbers. The association between the water quality parameters and bull trout numbers was visually examined with scatter plots created in R where the Y-axis was population numbers and the X was the water quality parameter. The plots were then fit with a linear regression line and from this a visual interpretation of the association and strength of said associated was determined. The analysis yielded unexpected results with only some of the water quality parameters exhibiting a negative relationship with road construction disturbance. Two water bodies (Flathead River and Warm Springs Creek) showed no significant changes in bull trout population numbers, and the control water body with no road construction (the Blackfoot River) displayed significant differences between the pre- and post-construction water quality parameter medians. The parameters that did display expected outcomes (cadmium concentration in the Flathead River; water temperature, pH, and instantaneous discharge in Warm Springs Creek; and instantaneous discharge, pH, and cadmium concentration in the Blackfoot River) were not all strongly correlated with decreased bull trout population numbers. The water quality parameters common to all the study rivers that presented a negative association with bull trout numbers was pH. High levels of recreation and management activities on the Blackfoot River (the control) could explain these unexpected findings. The results do, however, partially corroborate previous studies on the negative association between bull trout population numbers and road construction-related disturbance. A longer study period combined with finer-grained data would be beneficial for future studies.Item Tritrophic responses to signaling formulations sprayed in wheat stem sawfly-infested field plots(Montana State University - Bozeman, College of Agriculture, 2019) Caron, Christopher G.; Chairperson, Graduate Committee: Scott PowellThe wheat stem sawfly (Cephus cinctus Norton) is an economically important pest of wheat in the Northern Great Plains of North America. Producers and researchers are continuing to search for an effective management strategy. A combination of management tactics, such as host-plant resistance and biocontrol, may be the best method to suppress wheat stem sawfly (WSS) populations. My study examines whether direct toxicity, induced host-plant resistance, or the manipulation of tritrophic interactions, can be achieved through the application of signaling molecules in WSS-infested plots. The overall objective was to assess whether signaling molecules could be incorporated as a management tactic for WSS. Field experiments assessed whether aqueous applications of methyl jasmonate (MeJA), methyl salicylate (MeSA), and Actigard? influence WSS fitness, host-plant fitness, or the recruitment of natural enemies. Treatments were applied in WSS-infested plots for 3 consecutive weeks in both 2017 and in a second experiment in 2018. Wheat samples were collected before harvest and processed to assess parameters of infestation and parasitism. Plant growth and yield parameters were also recorded. The field trials suggested that MeJA and Actigard? induced significant changes that can impact tritrophic interactions in winter wheat. No effect was observed from the applications of MeSA. WSS fitness parameters decreased with applications of MeJA. MeJA treated plots had decreased infestation (2017), decreased larval weight (2018), and increased neonate mortality (2018). Actigard? treated plots had decreased larval weight and increased recruitment of clerid beetles (Phyllobaenus dubius Wolcott) (2017). Treatments of MeJA decreased stem height and grain weight, while treatments of Actigard? decreased grain weight in 2017. Although many of these findings were not consistent for both growing seasons, this study demonstrates the potential for these signaling molecules to manipulate the interactions between the WSS, or its host plant, and associated natural enemies in winter wheat.Item A risk assessment for hillslope erosion from wildfire and implications for water quality and watershed ecology(Montana State University - Bozeman, College of Agriculture, 2019) McGunagle, Patrick Timothy; Chairperson, Graduate Committee: Robert K. D. PetersonIn the western United States, wildfire is a natural disturbance and regulatory mechanism by which vegetated watersheds reset the natural succession regime. Wildfire management by humans protect property, people's lives, and values such as freshwater provision or recreational opportunity. However, erosion is a natural process that is directly exacerbated by wildfire. Erosion as debris flows, mass-wasting, or increased sedimentation is a continual phenomenon augmented by natural disturbance; fire plays an important role in stream channel development and floodplain connectivity. Hillslopes are the flanks of a valley and the margins of the eroding uplands and they vary in form and are indicative of the local geology and soils. However, ground observations to determine hillslope characteristics is expensive and negates the positive benefit of risk assessment as a "fast, cheap, good" method for targeting areas to manage a watershed for erosion risk. Therefore, my paper presents a risk assessment demonstrating the knowledge gap that limits economical risk management decisions to a pre-disturbance environment. I discuss hillslope erosion as the primary disturbance effect that can be managed pre-fire by the characterization of risk through an integrated ecological risk assessment. A beneficial outcome of accurate ecological risk assessment is knowledgeable resource triage in emergency situations, as well as the ability to proactively and economically manage for anticipated ecological effects. In addition, incorporating ecological risk metrics to a pre-disturbance management plan allows for inherently ecologically-sound operational objectives. I explore the risk of hillslope erosion from wildfire and how erosion from wildfire affects water quality and watershed ecology. I review the current understanding of erosion potential and how to minimize wildfire impact. I then demonstrate how to use the Total Risk Quotient to manage for total risk. I find that risk assessment for hillslope erosion requires interpreting layers of risk established by the topography, the fire, the storm, and the timing of these events. I conclude that whenever multiple natural phenomena affect resources and value, economic analysis to understand the total risk and risk mitigation options is required.Item The impact of elevation and proximity to trails on plant biodiversity in mountain ecosystems surrounding Flagstaff, AZ, USA(Montana State University - Bozeman, College of Agriculture, 2019) Morford-Graziano, Dawn Marie; Chairperson, Graduate Committee: Scott PowellThe objectives of this project were to compare biodiversity along an elevation gradient in the mountains surrounding Flagstaff, Arizona. In addition, identify the presence or absence of four specific non-native species being monitored using the Mountain Invasion Research Network (MIREN) protocol: common yarrow (Achillea millefolium), red clover (Trifolium pratense), white clover (Trifolium repens), narrowleaf plantain (Plantago lanceolata). The study used T-shaped transects at randomly selected sampling locations to collect data on richness and abundance of plant species up to 22 m from four hiking trails. Measured sample location was the middle point of the trailside or "near" sample unit. The "near" sample unit (2 m deep * 10 m parallel) was parallel with the trail. The other two sample units "middle" and "far" were perpendicular to the trail, starting 2 m from the measured sample location. Simpsons (1-D) and Shannon's Index were used to determine alpha biodiversity (diversity within a community (Magurran & McGill, 2011) along the elevation gradient. Jaccard Index and Morista-Horn Index used to compare dissimilarity of beta diversity (diversity between communities (Magurran & McGill, 2011)) between elevation zones and proximity to the trail. Dissimilarity is the amount of difference between communities. The study demonstrated species richness decreased as sample location elevation increased. Species richness also decreased as the distance from the trail increased. Simpson's and Shannon's biodiversity indices both showed a statistically significant difference in biodiversity values decreasing with an increase in elevation. Dissimilarity index values for both beta diversity indices indicated a statistically significant difference in dissimilarity based on proximity to the trail. The presence of common yarrow was only found at two sampling locations preventing further analysis. All trails had similar relative abundances but the dominant species along each trail was different. Elevation plays a determining role in the richness and diversity of species in mountain ecosystems surrounding Flagstaff, Arizona.