Limited Evidence For Co2-Related Growth Enhancement In Northern Rocky Mountain Pinus Contorta Populations: Trends In Growth And Intrinsic Water-Use Efficiency Across Climate Gradients, Charlotte C. Reed

Graduate Student Theses, Dissertations, & Professional Papers

Forests sequester large amounts of carbon annually; however, the degree to which enhanced forest productivity is due to more conducive climate or CO₂ fertilization remains uncertain. Increasing atmospheric CO₂ may enhance photosynthesis and/or decrease stomatal conductance thereby enhancing intrinsic water use efficiency (iWUE). While increasing iWUE has been observed in most trees globally, this increase does not necessarily translate into greater growth. This study aims to evaluate whether responses of radial growth and iWUE to increasing CO₂ vary across climatic gradients. To investigate interactions between climate and CO₂ and their impacts on tree physiology and growth, …

Growth Response Of Whitebark Pine (Pinus Albicaulis) Regeneration To Thinning And Prescribed Burn Release Treatments, Molly L. Mcclintock Retzlaff

Graduate Student Theses, Dissertations, & Professional Papers

Whitebark pine (Pinus albicaulis Engelm.) plays a prominent role throughout high-elevation ecosystems in the northern Rocky Mountains. It is an important food source for many birds and mammals, as well as a major player in high-elevation watershed maintenance, both slowing snowmelt and stabilizing soils. Whitebark pine is vanishing from the landscape due to three main factors – white pine blister rust (Cronartium ribicola) invasions, mountain pine beetle (Dendroctonus ponderosae) outbreaks, and successional replacement by more shade-tolerant tree species historically controlled by wildfire. In the past century, human activity such as fire suppression has altered these …

Harvest And Persistence Of Wolf Populations: Variable Effects Of Harvest On Wolf Packs In The Rocky Mountains, Sarah B. Bassing

Graduate Student Theses, Dissertations, & Professional Papers

Pubic harvest is a common method used to manage populations of wolves (Canis lupus) in North America. Although wolves appear resilient to the effects of harvest management the influences on demography and pack stability are uncertain. Packs generally drive population dynamics for wolves; thus, we were interested in how harvested populations were maintained and how harvest influenced the abundance and distribution of packs. We used noninvasive genetic data collected in Idaho, USA (2008–2014) and Alberta, Canada (2012–2014) to test whether immigration compensated for harvest mortality and helped maintain population densities. We further fit occupancy models to detection data …

Changes In Postural Sway Behavior Across The Life Span, Maria M B N R Santos

Graduate Student Theses, Dissertations, & Professional Papers

The present study aimed to investigate human balance control by assessing postural sway on three groups representing three stages of life (6-12, 19-40 and 65-74 years old). There were 14 individuals in each group and they were tested during upright bipedal stance with either eyes open or closed. Focus was given to multiple sway indices representing multi-dimensional features of postural sway in quiet stance and included: the center of pressure area, amplitude, root mean square (RMS), velocity, jerkiness, and sample entropy. Results confirmed that children and seniors swayed more (p<.004), faster (p<.001) and their body sway was shakier (p<.001) than young adults. Seniors also presented faster (p<.006) and shakier (p<.001) sway than children and a more unpredictable pattern of body sway in time (p<.002) than children and young adults. In addition, children presented a more random anterior-posterior sway (p<.034) and a more regular medio-lateral sway (p<.043) than young adults, and a higher synchronization between anterior-posterior and medio-lateral body sway (p<.012) than young adults and seniors. We also observed that postural control of children and young adults becomes relatively more challenged in experimental situations when eyes were closed for most postural indices. In conclusion, this study suggests that multi-dimension posturography is sensitive to detect subtle age-related changes in the postural behavior and each stage of life may have their own signature patterns of postural behavior. Therefore, we expect that quantifications of this nature may be used to assess not only postural instability and fall risk but also to aid the testing of the efficacy of balance interventional protocols.

Structural Integrity And Physical Properties Of Ponderosa Pine Over Time After Death Between Vectors Of Mortality, Edward J. O'Donnell

Graduate Student Theses, Dissertations, & Professional Papers

In an era of accelerated climate change, with persistent and increasing disturbance on our landscapes it is important to increase our knowledge of how these natural disturbances effect our lands. This study investigated the changes that take place in ponderosa pine (Pinus ponderosa) stems after death when killed by mountain pine beetle (Dendroctonus ponderosae) and by fire. Trees killed by mountain pine beetle as well as trees killed by fire were sampled and separated into two age classes, those dead 0-4 years and those dead 4+ years. Data was gathered on the modulus of rupture, modulus …

Integrated Stress And Community Perceptions: Toward An Understanding Of Human-Cougar Tolerance, Lara Brenner

Graduate Student Theses, Dissertations, & Professional Papers

Evidence suggests that cougars (Puma concolor) are beginning to recolonize their traditional range in the Midwestern and Eastern US, returning to a landscape and a social environment that have changed drastically in a century of absence. Any hope of the cougar’s persistence depends on both human tolerance of their presence and on cougar tolerance of disrupted habitat. In this thesis, we took advantage of diverse cougar policy in place in the Western US to explore variation in human attitudes and acceptability of cougars and in the cougar stress response. We validated a process to identify and extract cortisol …

Response Of Amphibian And Invertebrate Communities To Wetland Mitigation In The Greater Yellowstone Ecosystem, Leah K. Swartz

Graduate Student Theses, Dissertations, & Professional Papers

Wetlands play a critical role in supporting freshwater biodiversity and ecosystem services, but human activities have resulted in large-scale loss and degradation of these habitats across the globe. To offset the decline of wetland area, mitigation wetlands are now frequently constructed, but their ability to replace the functions of natural habitats, including providing habitat for native fauna, remains uncertain. A recent highway reconstruction project in northwestern Wyoming caused impacts to and the destruction of multiple natural wetlands. To mitigate this loss, new wetlands were constructed along the highway corridor. To evaluate the performance of these created wetlands relative to reference …

Evolution Of Molt Phenology In Dwarf Hamsters, Zachary Clare-Salzler

Graduate Student Theses, Dissertations, & Professional Papers

Environmental seasonality presents many challenges for survival. In response, organisms from across the tree of life exhibit adaptive phenology, which can facilitate survival from season to season. In particular, many species are white in the winter and brown in the summer where winter snow cover alters the visual environment. There is an extensive body of literature describing the physiological and cellular regulation of this trait in the Siberian dwarf hamster (Phodopus sungorus), but there are major shortcomings in our understanding concerning the evolution and molecular regulation of mammalian skin phenology. Notably, little is known about the genetic basis …

Molecular Diversity Of Foliar Fungal Endophytes In Relation To Defense Strategies And Disease In Whitebark Pine, Lorinda Bullington

Graduate Student Theses, Dissertations, & Professional Papers

An invasive fungal pathogen, Cronartium ribicola (the causative agent of white pine blister rust) infects and kills whitebark pine (Pinus albicaulis) throughout the western US. Blister rust has decreased whitebark pine populations by over 90% in some areas. Whitebark pine, a keystone species, has been proposed for listing under the Endangered Species Act in the U.S., and the loss of this conifer is predicted to have severe impacts on forest composition and function in high elevations. Hundreds of asymptomatic fungal species live inside whitebark pine tissue, and recent studies suggest that these fungi can influence the frequency and …

Sms Parent Action Intervention (Span): A Pilot Study To Assess The Feasibility Of Using Text Messaging To Promote Child Health On An American Indian Reservation, Julia M. Malich

Graduate Student Theses, Dissertations, & Professional Papers

Abstract

Purpose: Childhood obesity and its associated health risks are widely recognized as a major public health crisis in the United States (Johnson & Johnson, 2014; Proctor, 2008; Rogers et al, 2013; Vinci et al, 2016) and worldwide (Elías-Boneta, Toro, Garcia, Torres, & Palacios, 2015). Among children in low-income families, American Indian/Alaska Native (AIAN) children have the highest prevalence of obesity (21.1%) compared to other racial/ethnic groups (14.74% overall) (Pan et al, 2015). Parents play an important role in introducing healthy foods and encouraging physical activity in young children (Birch & Ventura, 2009; Lindsay et al., 2006; Natale et al., …

K-Mer Analysis Pipeline For Classification Of Dna Sequences From Metagenomic Samples, Russell Kaehler

Graduate Student Theses, Dissertations, & Professional Papers

Biological sequence datasets are increasing at a prodigious rate. The volume of data in these datasets surpasses what is observed in many other fields of science. New developments wherein metagenomic DNA from complex bacterial communities is recovered and sequenced are producing a new kind of data known as metagenomic data, which is comprised of DNA fragments from many genomes. Developing a utility to analyze such metagenomic data and predict the sample class from which it originated has many possible implications for ecological and medical applications. Within this document is a description of a series of analytical techniques used to process …

Drivers And Feedbacks Of The Fire-Grazing Interaction In The Northern Great Plains, Jacob E. Powell

Graduate Student Theses, Dissertations, & Professional Papers

The fire-grazing interaction is well studied in mesic grasslands worldwide, but research is lacking in semiarid systems. In addition, the fire-grazing interaction reduces the invasion of exotic forage species in mesic grasslands by increasing the scale of grazing selection and may be a tool to control invasive plants in other grasslands. We examined the principal drivers and feedbacks of the fire-grazing interaction on the strength of cattle grazing selection, forage quantity and quality, and vegetation structure and composition in two pastures in northeast Montana at The Nature Conservancy’s Matador Ranch. We also determined the influence of time since fire, within …

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 …

Contributions Of Gene Copy Number Variation To Genome Evolution And Local Adaptation Of The Cyanobacterium Acaryochloris, Amy L. Gallagher

Graduate Student Theses, Dissertations, & Professional Papers

Acaryochloris is a recently discovered genus of cyanobacteria, unique in its use of an uncommon chlorophyll as its major photosynthetic pigment, and in its peculiar genome dynamics. Members of this genus exhibit increased genic copy number variation (CNV), which is thought to be primarily derived from gene duplications and horizontal gene transfer (HGT). Acaryochloris provides an ideal system to explore mechanisms behind maintenance of gene duplicates and the influence of CNV in local adaptation. Here, I propose a mechanism for retention of gene duplicates of the bacterial recombinase, RecA, in Acaryochloris genomes and provide preliminary evidence that these paralogs are …

Does Timing Of Herbicide Use Influence Rates Of Germination Or Seedling Biomass Of Native Plants Used For Restoration?, Christine Mcmanamen

Graduate Student Theses, Dissertations, & Professional Papers

Invasive plants can negatively impact native grasslands by changing their species composition, productivity, and function. Managers commonly use herbicides as a control method; however, this practice can lead to secondary invasion by other non-native invasive plants, unless measures are taken to promote natives. Because of this, managers often seed native plants after spraying herbicides. There is evidence, however, that chemical control of invasive plants may reduce the effectiveness of subsequent seed-addition treatments, but there is currently little quantitative information on optimal timing between spraying and seeding or on variation in herbicide sensitivity among native plants commonly used in seed mixes. …

Are Maximum Ground Forces And Leg Compression In Phase? A Test Of The Classical Spring Mass Model Of Running Gaits, Seth Donahue

Graduate Student Theses, Dissertations, & Professional Papers

The mechanical understanding of human running has classically been described as a spring-mass system, with subsequent models predicting the movements of the body’s center of mass and the forces applied by the leg against the ground. A central requirement of any spring system is the phasic relationship between the length of the elastic elements and the forces applied to these structures. Specifically, elastic elements compress under load and extend as the load is released. We tested whether this model applies to individuals with specialization for extreme performance in human gait. Recent work from elite level sprint runners suggest that their …

Poison In Pink, Sydney V. Cook

Graduate Student Theses, Dissertations, & Professional Papers

Humans slather, spray, mist, and cleanse their bodies with personal care products like lotion, hairspray, cologne, and shampoo every day. Our cupboards are stocked full of them, but few of us understand what is in those jars and bottles. We trust that if it’s on the shelf at the store, it’s safe. However, this is not always the case, and many personal care products contain chemicals that are harmful to human and environmental health.

My multi-disciplinary Environmental Studies thesis project combines evidenced-based research, interviews, nonfiction narrative, and science communication to create part of a book manuscript intended to educate general …

Evolution Of The Kinetics And Dynamics Of Heme-Crevice Loop Regulating Chemistry In Human Cytochrome C, Shiloh M. Nold

Graduate Student Theses, Dissertations, & Professional Papers

Cytochrome c, cytc, is a metalloprotein that plays primary roles in electron transport and intrinsic apoptotic pathways. Much of the chemistry that cytc is involved with is regulated by a highly conserved region known as the heme crevice loop, consisting of residues 70-85. Only three of these residues (those at positions 81, 83 and 85) are not universally conserved within the evolutionary timeline. Here I look to elucidate possible evolutionary roles for several of the key residues known to be important in regulating heme chemistry of cytc.

I first address the role that lysine …

¬Multilocus Phylogeny Of The Lichen Family Megasporaceae, Tim B. Wheeler

Graduate Student Theses, Dissertations, & Professional Papers

The lichen symbiosis is one of the oldest studied mutualisms; in fact, Frank and De Bary coined the term "symbiosis" while studying lichens (Frank, 1877; De Bary 1879). The widespread, stable association between the mycobiont and photobiont in lichens offers an ideal system for the study of co-evolution. The recent application of molecular data to lichens has begun to unveil the complexities involved in these associations (Upreti et al. 2015, Spribille et al. 2016). Lichenized fungi make up a huge fraction of fungal diversity (Nash 2008), yet very little is known of their genetic diversity. Fungal taxonomy is notoriously difficult …

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 …

High-Resolution Mapping Of Hierarchical Greater Sage-Grouse Nesting Habitat: A Grain-Spectrum Approach In Northwestern Wyoming, Robert T. Haynam Iii

Graduate Student Theses, Dissertations, & Professional Papers

Our overall objective was to create a probabilistic nesting-habitat map for the Jackson Hole sage-grouse population that would have utility as a tool for future research, conservation, and management. The models that we developed for this purpose were specified to evaluate whether sage-grouse may be selecting nesting-habitat characteristics simultaneously at various spatial scales. Our spatially-explicit landscape-scale research was implemented primarily with readily available National Agriculture Imagery Program (NAIP) data. All nesting data was collected from 2007-2010. We tested how a broad range of grain sizes (spatial resolution) of covariate values affected the fit to logistic regression models used to estimate …