Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 55 for “"soil microbial communities"”.
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Petroleum effects on soil microbial communities
… hydrocarbons. This work aimed to evaluate microbial community shifts in soils under crude oil contamination and assess the effects of Biodiesel co-product (BCP) as a protecting agent of soil microbiota under crude oil addition. We used soils from the Trindade Island and from the Highfield …
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Advancing Polycyclic Aromatic Hydrocarbon Bioremediation using Genetic Bioaugmentation in Soil Microbial Communities
… These compounds are carcinogenic and disrupt soil microbial processes essential for ecosystem functions. Bioremediation, which uses microorganisms to degrade pollutants, can be applied to ameliorate contaminated environments. However, biodegradative functions are often limited because …
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Environmental Controls Over the Distribution and Function of Antarctic Soil Microbial Communities
Microbial community composition plays a vital role in soil biogeochemical cycling. Information that explains the biogeography of microorganisms is consequently necessary for predicting the timing and magnitude of important ecosystem services mediated by soil biota, such as decomposition and …
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The Role of Volatile Organic Compounds on Soil Microbial Communities and Ecosystem Processes
Soil microorganisms are primarily limited by carbon (C) availability. The majority of C entering belowground food webs comes directly from local flora. Plant derived labile C compounds affect microbial community structure and function, which in turn drive ecosystem function. Research has focused on …
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Change in the Structure of Soil Microbial Communities in Response to Waste Amendments
Soil microbial communities are affected extensively by addition of amendments to their environment. Of particular concern is the addition of poultry litter, which contains a substantial C, energy, and nutrient supply, but also antibiotic resistance genes (ARG), antimicrobials, and a multitude of …
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Effects of land management and climate change on soil microbial communities in Appalachian forest ecosystems
… (C), nitrogen (N), and phosphorus (P). These microbial functions are critical for promoting ecosystem services that support human well-being, such as provisioning of clean drinking water, nitrogen retention, and carbon storage. In forests of the Appalachian region of the eastern US, these …
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Effects of Organic and Conventional Agricultural Practices on Soil Microbial Communities and Molecular Detection of Soil Borne Disease
<p>Agricultural practices affect soil microbial communities and health through the input of pesticides, herbicides, fertilizers, and cycling of crop rotation. By examining the microbial community structure, we analyzed how microbial species respond to the environment that individual farms create. …
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Soil microbial function in a time of global change: effect of dairy antibiotics on soil microbial communities and ecosystem function
… for human health, the potential to disturb microbial communities and ecosystem functions they regulate is under appreciated. Antibiotics are commonly used in the livestock sector, accounting for 80% of antibiotic use domestically. This dissertation addresses three facets of this problem. …
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What shapes instruction in course-based undergraduate research experiences? & Spatial, temporal, and structural drivers of soil microbial communities in regenerative agricultural systems
… 2 Conventional agricultural practices degrade soil structure, nutrients, and microbial communities essential for food production. Regenerative agriculture (RA) can counter these effects through practices that support microbial diversity and ecosystem resilience. This study analyzed soils from …
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The Effect of Prescribed Burning on Soil Microbial Communities, Nutrients, and Carbon Dioxide Fluxes Under and Between Sagebrush Canopies in the Semi-Arid Rangelands of Northern Nevada
… to cause immediate and long-term changes to soil microbial communities, nutrient dynamics, and carbon dioxide (CO2) fluxes. These changes can have direct and indirect effects on soil biochemistry and respiration. The effects of fire on soil largely depend on time and seasonality, frequency, …
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Patterns in forest soil microbial community composition across a range of regional climates in Western Canada
Soil microbial communities can be characterized by community structure and function (community composition) across a spectrum of spatial scales, and variation in soil microbial composition has been associated with a number of environmental gradients. This study investigates the structure and …
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The response of grassland carbon cycling to drought events and changes in nutrient availability
… events will not be consistent across grassland communities, instead likely varying with grassland properties. One such property may be the level of nutrient availability, which brings about changes in plant productivity, plant community composition, and soil microbial composition and function. …
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Community Ecology Of Soil Microbes In Southeast Usa Oak-Pine Woodlands
Soil microbial communities can have important effects on plant growth and plant community ecology; however, the relationships between trees and soil microbial communities are still relatively poorly understood. Here i examine several of these relationships. Chapter 1 examines how ecological …
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Interactions between cover crop residue and microbial community affect weed suppression
… inhibit weed germination, growth and production. Soil microbial communities are especially important for the allelochemical potential of a cover crop residue, because microorganisms can modify residues and allelochemicals to make them more or less phytotoxic. In addition to their effects on …
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Influence of landscape-variation in geochemistry on taxonomic and functional composition of microbial mat communities in the McMurdo Dry Valleys, Antarctica
Microbial communities play critical roles in biogeochemical cycles of aquatic and terrestrial ecosystems, but studies of soil microbial communities have been limited by the diversity and complexity found in most ecosystems. Here we report on work investigating the functional diversity of microbial …
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Antimicrobial resistance in soil: long-term effects on microbial communities, interactions with soil properties, and transport of antimicrobial elements
… resistance genes (ARGs) naturally occur in soils, increasing abundances of ARGs correlate with increased antibiotic usage in agricultural settings. When livestock are treated with antibiotics, the antibiotic compounds, ARB, and ARGs can enter soil via manure excreted onto pastures or applied …
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The Effects of dairy cattle antibiotics on soil microbial community cycling and antibiotic resistance
… to increase resistance to antibiotics in soil microbial communities since 40-95% of an antibiotic dose administered to livestock is excreted intact or as metabolites. Exposure to antibiotics is also known to alter microbial community composition, biomass, and physiology, but the potential …
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Patterns, Processes And Models Of Microbial Recovery In A Chronosequence Following Reforestation Of Reclaimed Mine Soils
Soil microbial communities mediate important ecological processes and play essential roles in biogeochemical cycling. Ecosystem disturbances such as surface mining significantly alter soil microbial communities, which could lead to changes or impairment of ecosystem functions. Reforestation …
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Soil microbial response to land management practices and wildfire in Appalachian ecosystems
… is critically controlled by the activity of soil microbial communities. Understanding how soil microbial communities change as a result of different land management practices or natural disturbances can provide insight into the effects of these perturbations on ecosystem health, such as water …
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Long-term n fertilization affects soil bacterial communities in agronomic fields
Soil microbial communities influence plant productivity, chemistry and structure of soil and nutrient cycling. In turn, long-term nitrogen fertilization changes soil physical and chemical properties and thus influences soil microbiomes. In-depth understanding of the long-term nitrogen fertilization …
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