Environmental Microbiology and Microbial Ecology Commons^™

Characterization Of The Rumen Bacterial Communities Of Bison Heifers Fed A Grass-Based Diet Vs A Grain-Based Free-Choice Diet, Anlly Miley Fresno Rueda

Electronic Theses and Dissertations

A century ago, the North American grasslands and prairie ecosystems were dominated by bison. At least 30 million bison roamed the Great Plains when the first explorers arrived. By 1900, there were little over a thousand bison remained in the United States and Canada. Recovery efforts has been made since the 20th century to reestablish the herds and increase the bison population. Today, over 500,000 bison are distributed across North America, with more than 90% of the existing bison population under commercial production. Modern conservation strategies are made via the collaborative efforts of conservationist, producers, and researchers, resulting in increased …

Impact Of Arbuscular Mycorrhizal Fungi On Conyza Canadensis Drought Responses And Possible Mechanisms, Kian G.M. Speck, Ylva Lekberg, Anna Sala

Undergraduate Theses, Professional Papers, and Capstone Artifacts

• Arbuscular mycorrhizal fungi (AMF) are important plant mutualists that can facilitate plant responses to various environmental stressors, such as drought. A plant that may benefit from AMF-induced drought tolerance is Conyza canadensis due to its ability to thrive in dry conditions and its high colonization rate. However, no studies have researched C. canadensis in this context and the exact mechanisms of AMF-induced drought tolerance are still unknown.
• To better understand if and how AMF facilitate drought response in C. canadensis, we conducted a greenhouse experiment comparing the response of mycorrhizal and non-mycorrhizal plants to three watering levels. We measured …

Remnant Assessment And Soil Inoculation To Inform Large-Scale Prairie Restoration At Eastern Washington University, Erik E. Peterson

EWU Masters Thesis Collection

The Palouse Prairie of Eastern Washington and Western Idaho, characterized by rolling hills of deep loess soil, is one of the most endangered ecosystems in the world, with more than 99% converted to tilled farmland. To mitigate this loss, Eastern Washington University has begun prairie restoration on a tilled wheat field adjacent to campus, in the northern extent of the Palouse Prairie Ecoregion. However, effective restoration requires understanding reference conditions, and there are relatively few studies of remnant prairie plant communities or soils, particularly in the Northern Palouse. From north to south in the Palouse Prairie Ecoregion, there are gradients …

Roles Of Non-Frankia Bacteria In Root Nodule Formation And Function In Alnus Sp., Kelsey Christine Mercurio

Honors Theses and Capstones

Plant roots are home to a wide variety of beneficial microbes; understanding and optimizing plant-microbe interactions may be critical to enhance global food security in a sustainable, equitable way. With the help of their nitrogen-fixing bacterial partner, Frankia, actinorhizal plants form symbiotic root nodules and play important roles in agroforestry and land reclamation. However, Frankia does not live alone in nodules, and the other microbial residents may contribute to nodule formation and function. We collected root nodules from alder trees (Alnus sp.) in 2018 and 2019, then isolated DNA and individual bacterial strains to characterize the nodule microbial …

Determining The Effects Of Imidacloprid On Non-Target Soil Organisms In Hemlock Stands, Braley Burke

Graduate Theses, Dissertations, and Problem Reports (ETD)

The hemlock woolly adelgid (HWA), Adelges tsugae Annand (Hemiptera: Adelgidae), is an invasive insect that is causing mortality of eastern hemlock trees, Tsuga canadensis, and Carolina hemlock trees, Tsuga caroliniana, across the eastern United States. To protect these ecologically important tree species, a neonicotinoid insecticide, imidacloprid, is commonly used. Imidacloprid is an effective treatment and can remain effective against HWA for four to six years but long-term (≥ one year after application) non-target effects of imidacloprid on forest ecosystems are not well-studied. This study examined terrestrial non-target effects of imidacloprid in hemlock stands with different treatment histories to …

Comparison Of The Effects Of Land Use / Land Cover On Water Quality And The Intertidal Marine Macroalgae Communities At The Fluvial Outflows Of The Dingle Peninsula, Cassandra Lew

Theses

The Milltown, Feohanagh, and Owenmore river basins located on the Dingle Peninsula in Ireland were studied to see how variation in land use and land cover (LU/LC) affected water quality and the macroalgal communities at each river’s respective fluvial outflow. Abundance and composition of macroalgae in river and coastal water bodies have been designated as an indicator of water quality according to the Water Framework Directive 2000. The results of this study found that the Feohanagh’s macroalgal community had the highest species richness for most months while the Milltown had the highest Shannon Diversity Index. The Owenmore’s community was consistently …

Effects Of Biofertilizer On Soil Nutrient Cycling And The Productivity Of Bioproduct Crops In Marginal Soils, Kieran B. Liseski

Graduate Theses, Dissertations, and Problem Reports (ETD)

Recently there has been increased interest in the use of marginal lands in order to grow bioproduct crops. Utilizing marginal lands to grow bioproduct crops such as Miscanthus x giganteus and Panicum virgatum could not only improve soil quality and minimize negative environmental impacts on the surrounding ecosystems but could also offer economic benefits to growers in rural areas. Because marginal soils tend to reduce crop yields compared to prime farmlands even when growing bioproduct crops, which tend to be more robust than traditional food crops, augmenting the soil with biofertilizers (i.e., the direct addition of viable microbial cells) could …

Comparing Capabilities Of Shewanella Oneidensis Mr-1 And The Microbial Community Of Iron Caves To Reduce Fe(Iii), Aaron Douglas Pham

Williams Honors College, Honors Research Projects

Caves are generally formed by the erosion and/or dissolution of rock and its subsequent removal by water. Iron ore caves (IOCs) form despite being hosted by relatively insoluble and weathering-resistant rock. Due to the discovery of a microbial community behind the walls of these caves, it was hypothesized that these bacteria could be responsible for speleogenesis. Iron ore exists in an oxidized (Fe(III)) state, but reduced (Fe(II)) form is soluble. It was further reasoned that the bacteria might be able to reduce Fe(III) through direct metabolic activity, which uses iron as an electron acceptor. Here we show that cave microorganisms …

Review: Formation And Metabolic Function Of Coral Rubble Biofilms In The Reef Ecosystem, Andres Sanchez-Quinto, Luisa I. Falcon

Gulf and Caribbean Research

When coral dies, their calcareous skeletons constitute coral rubble in conjunction with the cementing activity of coralline algae and bacteria, creating a secondary reef structure which takes from years to decades to form. Healthy coral reefs differ from coral—rubble dominated reefs in microbial taxonomic composition and metabolic functional roles. The metabolisms of healthy reefs are dominated by autotrophic pathways, where carbon and nitrogen fixation dominate, while the metabolism of rubble—dominated reefs predominate in degradation of organic matter. Nitrogen fixation is 3 orders of magnitude lower in rubble—dominated reefs than in healthy reefs. Coral—rubble harbors a vast diversity of microbes that …