Theses and Dissertations at Montana State University (MSU)
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Item The response of parafluvial soils to beaver mimicry restoration in a Montane stream(Montana State University - Bozeman, College of Agriculture, 2020) Whitehead, Briana Katherine; Chairperson, Graduate Committee: Tracy M. Sterling and William Kleindl (co-chair); Paul Stoy, William Kleindl, Martin Rabenhorst, Rob Payn, David Wood and Anthony Hartshorn were co-authors of the article, 'Parafluvial soil response to beaver mimicry restoration in a montane stream' submitted to the journal 'Restoration ecology' which is contained within this thesis.Beaver Mimicry Restoration (BMR) is a relatively new aquatic restoration practice that seeks to improve deteriorated stream ecological functions. BMR is designed to rejoin hydrologically disconnected streams with their adjacent floodplains via the installation of small-scale, stream-spanning structures derived from natural materials and inspired by the influence of natural beaver (Castor spp.) dams. These structures capture sediment, elevate stream stage and groundwater tables, create thermal refugia, and re-establish riparian vegetation. Most research on BMR has focused on the hydrological or botanical results, but little is known about the response of parafluvial soils. I report measurements of soil water content, soil temperature, soil biogeochemical reduction, and vegetation responses at paired BMR-influenced treatment and non-BMR-influenced control locations from June through September of 2018 and 2019 in a montane stream in southwestern Montana (USA). In comparison to soils at control sites, soils adjacent to BMR activity experienced an extended period of higher water contents (0.23 m 3/m 3 higher), increased anoxic conditions (on average 27% more during the field season), a less variable and cooler soil temperature range (on average 5 °C cooler), and supported longer durations of vegetation greenness (additional 20 days) during the dry months. Results demonstrate how BMR produces conducive conditions for the development of new and/or the reestablish of historic hydric soils.Item 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 Restoring Russian knapweed-infested riparian areas(Montana State University - Bozeman, College of Agriculture, 2003) Laufenberg, Stephen Michael; Chairperson, Graduate Committee: Roger L. Sheley.Item Establishment of native and invasive species along a riparian resource gradient(Montana State University - Bozeman, College of Agriculture, 2000) LeCain, Ronald RoyItem Use of vegetative filter strip for controlling nitrate and bacteria pollution from livestock confinement areas(Montana State University - Bozeman, College of Agriculture, 2000) Fajardo, Juan JoseItem Mapping and change detection of wetland and riparian ecosystems in the Gallatin Valley, Montana using landsat imagery(Montana State University - Bozeman, College of Agriculture, 2004) Baker, Corey Ryan; Chairperson, Graduate Committee: Rick Lawrence.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 distinguish wetlands and riparian areas from the rest of the landscape. CTA creates a single classification tree using a one-step-look-ahead procedure to reduce variance. SGB utilized classification errors to refine tree development and incorporated the results of multiple trees into a single best classification. The SGB classification (86.0% overall accuracy) was more effective than CTA (61.7% overall accuracy) at detecting a variety of wetlands and riparian zones present on this landscape. A change detection analysis was performed for the years 1988 and 2001. The change detection used Landsat-based Tasseled Cap (TC) components and change vector analysis (CVA) to identify locations of wetland/riparian gain or loss in the 13-year period. CVA of TC brightness, greenness, and wetness components reduces the compound errors of multi-date classifications by using a threshold value to separate land cover change from spectral variability between 1988 and 2001 imagery. Only the highly changed pixels were classified using 1988 Landsat imagery and ancillary data. These change pixels were then merged with the 2001 classified image to develop a wetland/riparian map for 1988. The high overall accuracy of the 1988 classification (81%) developed with this procedure showed the benefits of this technique for mapping historical landcover features. Comparison of the 1988 and 2001 classifications identified locations where wetlands/riparian areas increased, decreased, or remained stable between these years. TC based CVA had an overall change detection accuracy of 75.8% and was able to identify areas of isolated and contiguous wetland/riparian change.Item Hydrology and landscape structure control subalpine catchment carbon export(Montana State University - Bozeman, College of Agriculture, 2009) Pacific, Vincent Jerald; Chairperson, Graduate Committee: Brian L. McGlynn.Carbon export from high elevation ecosystems is a critical component of the global carbon cycle. Ecosystems in northern latitudes have become the focus of much research due to their potential as large sinks of carbon in the atmosphere. However, there exists limited understanding of the controls of carbon export from complex mountain catchments due to strong spatial and temporal hydrologic variability, and large heterogeneity in landscape structure. The research presented in this dissertation investigates the control of hydrology and landscape structure and position on two major avenues of carbon loss from mountain watersheds: soil respiration and stream dissolved organic carbon (DOC) export. Measurements of soil respiration and its biophysical controls (soil water content, soil temperature, vegetation, soil organic matter, and soil physical properties) and stream and groundwater DOC dynamics are presented across three years and multiple riparian-hillslope transitions within a complex subalpine catchment in the northern Rocky Mountains, Montana. Variability in soil respiration was related to hydrologic dynamics through space and time and was strongly influenced by topography and landscape structure. Cumulative soil CO 2 efflux was significantly higher from wet riparian landscape positions compared to drier hillslope locations. Changes in hydrologic regimes (e.g. snowmelt and precipitation timing and magnitude) also impacted soil respiration. From a wet to a dry growing season, there were contrasting and disproportionate changes in cumulative growing season surface CO 2 efflux at wet and dry landscape positions. Stream DOC export was also influenced by landscape structure and hydrologic variability. The mobilization and delivery mechanisms of DOC from the soil to the stream were dependent upon the size of DOC source areas and the degree of hydrologic connectivity between the stream and the riparian and hillslope zones, which varied strongly across the landscape. This dissertation provides fundamental insight into the controls of hydrology and landscape structure on carbon export from complex mountain watersheds. The results of this research have large implications for the carbon source/sink status of high elevation mountain ecosystems, the influence of changing hydrologic regimes on soil respiration, and the use of landscape analysis to determine the locations of large source areas for carbon export.Item Variability in soil CO2 production and surface CO2 efflux across riparian-hillslope transitions(Montana State University - Bozeman, College of Agriculture, 2007) Pacific, Vincent Jerald; Chairperson, Graduate Committee: Bryan L. McGlynn.The spatial and temporal controls on soil CO2 production and surface CO2 efflux have been identified as an outstanding gap in our understanding of carbon cycling. I investigated both the spatial and temporal variability of soil CO2 concentrations and surface CO2 efflux across eight topographically distinct riparian-hillslope transitions in the ~300 ha subalpine upper-Stringer Creek Watershed in the Little Belt Mountains, Montana. Riparian-hillslope transitions provide ideal locations for investigating the spatial and temporal controls on soil CO2 concentrations and surface CO2 efflux due to strong gradients in respiration driving factors, including soil water content, soil temperature, and soil organic matter. I collected high frequency measurements of soil temperature, soil water content, soil air CO2 concentrations (20 cm and 50 cm), surface CO2 efflux, and soil C and N concentrations (once) at 32 locations along four transects. Soil CO2 concentrations were more variable in riparian landscape positions, as compared to hillslope positions, as well as along transects with greater upslope accumulated area. This can be attributed to a greater range of soil water content and higher soil organic matter availability.Item Composition and modeling of riparian vegetation in the West Fork of the Gallatin River watershed(Montana State University - Bozeman, College of Agriculture, 2007) Shoutis, Levia Nima; Chairperson, Graduate Committee: Duncan T. Patten.Riparian areas contribute to the health of watersheds through their influence on hydrologic, biogeochemical, physical, and ecological processes. Limited research has focused on riparian systems of small mountain watersheds in the western U.S., which are increasingly under pressure from development activities. Watershed managers would benefit from an increased understanding of environment-riparian relationships in mountainous watersheds, for the purpose of assessing habitat and potential available nutrient buffering. This study assessed vegetation-environment relationships using digitally-derived terrain variables and wetland indicator scores, and used these relationships to assess the composition and model the cross-valley extent of riparian vegetation within the West Fork of the Gallatin River watershed in southwest Montana. Digital terrain analysis was used to extract the following terrain predictors: elevation above and distance from streams, plot gradient, valley width, and a topographic wetness index, which integrates the upslope area that contributes flow to a plot, and the plot gradient, thus serving as a measure of site wetness. Species abundance was used to assign weighted plot wetland indicator scores in order to focus on cross-valley gradients, with plots below a threshold score (mesic plots) designated as riparian plots.Item How landforms and geology affect the structure of riparian areas(Montana State University - Bozeman, College of Agriculture, 2012) Anderson, Dustin Carl; Chairperson, Graduate Committee: Brian L. McGlynn; Clayton B. Marlow (co-chair)Current riparian zone assessments focus on the morphological features of the stream channel and ocular vegetation measurements. This procedure fails to address the hydraulic features responsible for the floristic structure and composition of the riparian zone. We looked at how the geology and landforms function as drivers of groundwater and surface-water exchange. These can mitigate watershed processes via groundwater availability to shape riparian processes; e.g. discharge, seasonality. We hypothesized that groundwater surface-water exchange is a first order process and that it dictates riparian water availability and that the underlying geology and landform can serve as a tool to gain greater understanding of a properly functioning riparian ecosystem. We tracked groundwater surface-water exchange using wells, piezometers, water temperature, conservative tracer injections and solute conductivity on an alluvial fan in the Gallatin valley. Southwestern Montana Conservative tracer injection indicated 3% tracer losses over the 1.5km reach. Through spring and summer 2011 groundwater wells and piezometers indicated flashy transient shallow groundwater. Significant late growing season stream discharge (~300 l/s) and standard riparian monitoring assessments would suggest a larger floristic community than what is present at the site. These metrics together suggest a disconnection between the surface-water and groundwater ultimately limiting the extent of the riparian vegetation community. We further determined that the surface water is disconnected from the local groundwater table. We conclude that the lack of surface water - groundwater connectivity drives the floristic structure and character of the riparian zone. Skewed or inaccurate views of riparian functionality may occur because; the current assessment fails to address surface water - groundwater connectivity.