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Filtering by: Creator McLaughlin, David J. Remove constraint Creator: McLaughlin, David J. Advisor Myrold, David D. Remove constraint Advisor: Myrold, David D.

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  • The link between nitrogen cycling and soil microbial community composition in forest soils of western Oregon

    Creator:
    Boyle, Stephanie A.
    Abstract:
    The objectives of this thesis were to examine the links between soil microbial community composition and function using the nitrogen (N) cycle as a model for these interactions and to assess the impact of environmental factors such as microclimate, vegetation type, and nutrient availability on microbial diversity and N transformations...
    Resource Type:
    Dissertation
    Full Text:
    . Rich, Peter J. Bottomley, Kermit Cromack Jr., David D. Myrold Reprinted from

  • Effects of vegetation and disturbance on fungal communities in the western Cascades of Oregon

    Creator:
    Kageyama, Stacie Ann, 1967-
    Abstract:
    The use of high throughput molecular methods that allow for the study of bacterial communities in environmental samples is commonplace in microbial ecology. Until recently, fungal community ecology has focused on isolation, collection of sporocarps, or collection of ectomycorrhizal roots. The techniques used to extract and amplify DNA from environmental...
    Resource Type:
    Dissertation
    Full Text:
    Oregon Stacie A. Kageyama, David D. Myrold, Peter J. Bottomley, and Kermit Cromack, Jr. Molecular

  • The development and decline dynamics of two ectomycorrhizal fungal mat soil microbial communities in response to a reciprocal soil transfer experiment in old-growth Douglas-fir forests

    Creator:
    Cappellazzi, Jed E.
    Abstract:
    Ectomycorrhizal fungi (EmF) form symbioses with trees. These symbioses profoundly influence forest ecology. Certain EmF form specialized profusions of hyphae, known as ectomycorrhizal fungal mats (mats) which are visible to the naked eye, alter forest soil biogeochemistry, substantially contribute to soil microbial biomass/respiration and support unique microbial communities. Piloderma and...
    Resource Type:
    Masters Thesis
    Full Text:
    : ________________________________________________________________________ David D. Myrold Jane E. Smith Ectomycorrhizal fungi (EmF) form symbioses with

  • Community composition and activities of denitrifying bacteria in soils

    Creator:
    Rich, Jeremy J.
    Abstract:
    Few studies have directly compared denitrifying community composition and activities in soils by coupling molecular-genetic techniques and traditional measures of denitnfication. I investigated communities of denitrifying bacteria from adjacent meadow and forest soils in the Cascade Mountains, Oregon. A key gene in the denitrification pathway, N₂O reductase (nosZ), served as...
    Resource Type:
    Dissertation
    Full Text:
    , Rachel S. Heichen, Peter J. Bottomley, Kermit Cromack, Jr., and David D. Myrold Applied and

  • The genetic diversity of Ceanothus-infective Frankia

    Creator:
    Ritchie, Nancy J.
    Abstract:
    Frankia from root nodules of nine different species of Ceanothus were characterized. DNA was amplified directly from nodular material using the polymerase chain reaction (PCR). The amplified region includes the 3' end of the 16S rRNA gene, the intergenic spacer (IGS), and a large portion of the 23S rRNA gene....
    Resource Type:
    Masters Thesis
    Full Text:
    ABSTRACT OF THE THESIS OF Nancy J. Ritchie for the degree of Master of Science in Soil Science presented

  • Inoculation potential of soil-borne Frankia on red alder (Alnus rubra Bong.)

    Creator:
    Martin, Kendall J.
    Abstract:
    Inoculation trials were set up in fumigated nursery beds for red alder (Alnus rubra Bong.) seedling production. Frankia inoculum was applied in eight treatments: control, nodule suspension, and three levels of cell suspension (strain ArI5) applied with and without a peat carrier. Seedlings were evaluated at midseason and lifting. The...
    Resource Type:
    Dissertation
    Full Text:
    AN ABSTRACT OF THE DISSERTATION OF Kendall J. Martin for the

  • Quantifying the fertilizer value of algal meal : an evaluation of an integrated dairy-anaerobic digester-algae production facility

    Creator:
    Andrews, Shannon B.
    Abstract:
    Algae have shown great potential as a source for renewable fuels. However, current production schemes have not been able to prove a sustainable energy return on investment due in part to the high costs of nutrient addition and the energy required for drying the biomass. Integrated algae-dairy production systems have...
    Resource Type:
    Masters Thesis
    Full Text:
    Dairy-Anaerobic Digester-Algae Production Facility Abstract approved: David D. Myrold

  • Toward understanding the nature of the soil microsite in relation to nitrogen and carbon cycling

    Creator:
    Cliff, John B.
    Abstract:
    My research has focused on understanding N and C cycling in soils at small scales. Isotope dilution methods commonly used to estimate gross rates of soil chemical transformations assume homogeneous distribution of label. I explored the effects of diffusion limitations on isotope dilution experiments in soil aggregates using spherical diffusion-reaction...
    Resource Type:
    Dissertation
    Full Text:
    especially like to thank Dr. David D. Myrold and Dr. Peter J. Bottomley for their dedication, tireless

  • Contributions of ammonia-oxidizing bacteria and archaea to nitrification in forest soils

    Creator:
    Lu, Xinda
    Abstract:
    Prior to 2005, ammonia oxidation, the first step of nitrification, was thought mediated mainly by ammonia-oxidizing bacteria (AOB). However, the discovery of Thaumarchaeota carrying the genes coding for the ammonia monooxygenase (AMO) enzyme led to the discovery that ammonia-oxidizing archaea (AOA) also contribute to nitrification. Despite the uptick in studies...
    Resource Type:
    Masters Thesis
    Full Text:
    : _____________________________________________________________________ David D. Myrold Prior to 2005, ammonia oxidation, the first step of nitrification, was

  • Evolution and ecology of the Ceanothus-Frankia symbiosis

    Creator:
    Jeong, Soon-Chun
    Abstract:
    The evolutionary relationship between Frankia and actinorhizal plants was evaluated by reconstructing molecular phylogenetic trees from nifH, 16S rDNA, and rbcL nucleotide sequences. Subgroupings in Frankia phylogenetic trees reconstructed from nifH and from 16S rDNA sequences were consistent in terms of plant origins of Frankia strains. Although the branching order...
    Resource Type:
    Dissertation
    Full Text:
    privacy ACKNOWLEDGMENTS First of all, I would like to express my special appreciation to Dr. David