Terrestrial and Aquatic Ecology Commons^™

Coupling Biophysical Complexity And Forest Metabolism In A Floodplain Landscape, Peter Davis

Graduate Student Theses, Dissertations, & Professional Papers

Floodplains are biophysically complex systems that are considered among the most productive and biodiverse ecosystems on Earth. Until recently, quantitative assessment of the relationship between complexity and terrestrial production has been constrained by technological limitation. To address how floodplain biophysical complexity and ecosystem function are related, I employed remote sensing, GIS, and spatial analyses to quantify and couple metrics of complexity and terrestrial production, as well as explore the relationship among complexity, vegetation structural diversity, and terrestrial primary productivity. The study site is a 6.75-km by 1.75-km portion of the Bitterroot River floodplain near Carlton, MT upon which 551 sample …

Understanding Patterns And Drivers Of Alaskan Fire-Regime Variability Across Spatial And Temporal Scales, Tyler J. Hoecker

Graduate Student Theses, Dissertations, & Professional Papers

Boreal forest and tundra ecosystems are globally important because the mobilization of large carbon stocks, and changes in energy balance could act as positive feedbacks to ongoing climate warming. In Alaska, wildfire is a key driver of ecosystem structure and function, and therefore fire strongly determines the feedbacks between high-latitude ecosystems and the larger Earth system. The paleoecological record from Alaska reveals the sensitivity of fire regimes to climatic and vegetation change over centennial to millennial time scales, highlighting increased burning with warming and/or increased landscape flammability associated with large-scale vegetation changes. This thesis focuses on two studies aimed at …

Assessing Stream Channel Restoration: The Phased Recovery Framework, Jacob M. Dyste

Graduate Student Theses, Dissertations, & Professional Papers

Channel reconfiguration projects command a large portion of stream restoration resources, while long-term monitoring and research is severely underfunded and rarely implemented. This has led to a limited knowledge base about ecological response and efficacy. Although channel reconfiguration projects are being implemented to restore biological function to lotic systems, the document responses are highly variable and little evidence has shown these projects are reaching their target goals. I predicted the inconsistent response to these projects is the result of disturbance-induced successional processes and catchment-scale water quality impairment. To address how these endogenous and exogenous factors influence stream response to channel …

Baseline Study Of Recovering Headwater Streams In The Sapphire Mountains, Western Montana, Morgan Vinyard

Graduate Student Theses, Dissertations, & Professional Papers

Many riparian areas in the western United States have been degraded by grazing and logging. In the year 2000, the Montana Department of Environmental Quality (DEQ) re-initiated an effort to identify and characterize reference streams, or least impacted streams in each region of the state. In Montana’s Bitterroot Valley, most streams have been impacted by grazing, irrigation, and timber production. The Montana DEQ has not been able to identify reference streams in the Sapphire Mountains on the east side of this valley. MPG Ranch, located on the west-facing slopes of the Sapphire Mountains and purchased in 2009 by a conservation-minded …

Spatio-Temporal Analysis Of Ungulate Browsing On Willow (Salix Spp.) Communities Within The Northern Range Of Yellowstone, Donald L. Belile Jr.

Graduate Student Theses, Dissertations, & Professional Papers

Variation in ungulate browsing intensity on willow (Salix spp.) communities across Yellowstone’s northern range has been attributed to various biophysical factors including climate, topography, and predators. These studies were conducted without a long-term browsing dataset; they lacked a spatially extensive sampling design, and did not include dynamic snow characteristics known to affect ungulate mobility, habitat selection, and foraging strategies. We therefore focused on snow, an extreme landscape level disturbance that places nutritional stress on ungulates during the winter when most browsing on shrubs occurs. We applied a non-destructive sampling method by consecutively recording whether stem leaders were browsed between …

Synthesis Of Satellite Microwave Observations For Monitoring Global Land-Atmosphere Co2 Exchange, Lucas Alan Jones

Graduate Student Theses, Dissertations, & Professional Papers

This dissertation describes the estimation, error quantification, and incorporation of land surface information from microwave satellite remote sensing for modeling global ecosystem land-atmosphere net CO₂ exchange. Retrieval algorithms were developed for estimating soil moisture, surface water, surface temperature, and vegetation phenology from microwave imagery timeseries. Soil moisture retrievals were merged with model-based soil moisture estimates and incorporated into a light-use efficiency model for vegetation productivity coupled to a soil decomposition model. Results, including state and uncertainty estimates, were evaluated with a global eddy covariance flux tower network and other independent global model- and remote-sensing based products.

Abundance, Density, And Opinions About Columbian Black-Tailed Deer, Whidbey Island, Washington, Robert P. Wingard

Graduate Student Theses, Dissertations, & Professional Papers

Obtaining reliable knowledge is the first step towards properly managing wildlife species. Columbian black-tailed deer (Odocoileus hemionus columbianus) on Whidbey Island, Washington have not been the subject of study, and little is known about the population, or the opinion of resident’s of Whidbey Island towards the deer population. However, wildlife managers suggest deer on the island may be overabundant or over social carrying capacity. Given the lack of empirical knowledge about the deer population or human opinions towards deer on Whidbey Island, I designed research to determine the abundance and density of Columbian black-tailed deer on Whidbey Island, …

Decadal Scale Responses Of Soil And Ecosystem Processes To Forest Restoration In Rocky Mountain Conifer Forests, Peter Ganzlin

Graduate Student Theses, Dissertations, & Professional Papers

Decades of fire suppression have left much of the forest in the intermountain western United States exceedingly dense, and forest restoration techniques – including thinning and prescribed fire – are increasingly being used in an attempt to mitigate the potentially disastrous effects of severe wildfire, to enhance tree growth and regeneration, and to stimulate soil nutrient cycling. While many of the short-term effects of forest restoration have been established, the long-term effects on soil biogeochemical and ecosystem processes are largely unknown. In this thesis I present two manuscripts documenting and synthesizing these long-term impacts. The first chapter focuses on the …

Use Of Airborne Digital Imagery To Examine Floodplain Complexity At Varying Discharges, Katelyn P. Driscoll

Graduate Student Theses, Dissertations, & Professional Papers

Floodplains are composed of aquatic and terrestrial habitats that are frequently reshaped by hydrologic processes operating at various spatial and temporal scales. I hypothesized that floodplain habitat complexity is maximized at intermediate discharges because small changes in flow result in substantial aquatic habitat changes and extreme discharges are associated with a decreased habitat heterogeneity. Between April and September 2014, I collected ultra-high resolution digital multispectral imagery of the Clark Fork River, Montana taken on 6 dates between early spring and fall. Following image mosaicking into a single image, unsupervised classification of the spectral reflectance was used to identify and quantify …

A Gis Assessment Of Ecoregion Representation In Chile's Existing And Proposed Integrated Network Of Protected Areas, Jessica Schutz

Graduate Student Theses, Dissertations, & Professional Papers

Chile's state designated protected areas are reported to show representation bias and to be unable to meet conservation goals. Private protected areas are considered an important tool to resolve these issues, which has led to support for increasing the role of private protected areas in Chile and creating an integrated public-private protected area network. But the validity of the capacity of private protected areas to fix Chile's state protected area network bias, and the advantage of creating an integrated protected area network, have not been assessed. This study uses the most recent data on Chile's state, private, and international protected …

Assessing Changes In Avian Communities, Jessie D. Golding

Graduate Student Theses, Dissertations, & Professional Papers

Grazing is a potentially powerful tool to address wildlife declines associated with land use conversion in the western United States. Grazing systems can be manipulated to achieve desired vegetation outcomes, preserve native habitat and economically benefit multiple stakeholders. As a result, systems designed to benefit native ecosystems are being widely implemented. However, the benefits of these grazing systems on many wildlife communities remain relatively unexplored. Songbirds provide an ideal study system to test these benefits because they continue to use native habitat that is currently grazed. Given limited time and resources, conservation practitioners often monitor a single focal species or …

Cows And Plows: Science-Based Conservation For Grassland Songbirds In Agricultural Landscapes, Marisa K. Lipsey

Graduate Student Theses, Dissertations, & Professional Papers

Temperate grasslands are among earth’s most imperiled ecosystems. In North America, steep declines of endemic songbird populations indicate that grassland loss and degradation may be approaching critical levels. Grasslands are agricultural landscapes largely (~85%) under private ownership with little formal protection status. Remaining bird populations depend on grazing lands that have not been converted to cropland. We combine regional data from a hotspot for grassland bird diversity (northeast Montana, USA; 26,500-km2) with continental data spanning the northern Great Plains (1,000,000-km2) to evaluate how land use and management influence bird distribution and abundance. Regionally, habitat used by seven grassland specialists spanned …

Community Perturbation Associated With New Zealand Mudsnail (Potamapyrgus Antipodarum) Invasion: Discrepancies In Temporal And Spatial Assessment, Eric H. Richins

Graduate Student Theses, Dissertations, & Professional Papers

Invasive species have the potential to alter the ecosystems within which they establish as well as adjacent but uninvaded ecosystems by altering the flow of nutrients or biota across system boundaries. New Zealand mudsnails (Potamopyrgus antipodarum; NZMS) are often very abundant where they invade, sequestering the majority of stream primary production. This sequestering of production may reduce aquatic insect production, subsequent insect emergence and subsidies to riparian ecosystems. Tetragnathid spiders, an insectivorous riparian specialist, are dependent on the emergence of aquatic insects and are typical indicators of aquatic insect subsidies to riparian zones. In addition, NZMS invasions can result …

Disturbed Waters – A Montana Chemist Searches For The Source Of A Persistent Poison, Kindra Mcquillan

Graduate Student Theses, Dissertations, & Professional Papers

In December 2008, when Montana's great Clark Fork River tested its historic banks for the first time in 100 years, a crowd of hundreds gathered to watch the removal of Milltown Dam at the confluence of the river with the Big Blackfoot. After a century of pollution from Butte's copper mines, the river was undergoing the nation's largest­yet restoration project, the Upper Clark Fork River Superfund Complex.

But in a windowless laboratory a mile away, University of Montana chemist Heiko Langner had troubling news. Toxic methylmercury flowed through the river at concentrations of concern, undetected and undermining the project. It …

Habitat Quality Influences Migratory Strategy Of Female White-Tailed Deer, Charles R. Henderson Jr.

Graduate Student Theses, Dissertations, & Professional Papers

Partial migration is a life history strategy that is common for ungulate species living in seasonal environments. One factor that influences the decision to migrate by ungulates is access to high quality habitat. We evaluated the influence of access to winter habitat of high quality on the probability of an individual migrating, the differences in seasonal habitat use between and within migratory and resident classes of deer, and the effects of this decision on the survival of female white-tailed deer. We hypothesized that deer with home ranges of relatively low quality in winter would have a relatively high probability of …