| 项目编号: | 1656027
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| 项目名称: | Unraveling the paradox of dissimilatory nitrate reduction to ammonium in upland soils |
| 作者: | Wendy Yang
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| 承担单位: | University of Illinois at Urbana-Champaign
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| 批准年: | 2017
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| 开始日期: | 2017-07-01
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| 结束日期: | 2019-06-30
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| 资助金额: | 150000
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| 资助来源: | US-NSF
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| 项目类别: | Standard Grant
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| 国家: | US
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| 语种: | 英语
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| 特色学科分类: | Biological Sciences - Environmental Biology
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| 英文关键词: | dnra
; ammonium
; soil microbe
; paradoxical understanding
; soil leaching
; process
; soil biology
; laboratory soil microcosm experiment
; dissimilatory nitrate reduction
; forest soil
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| 英文摘要: | Nitrogen is a critical nutrient that is often limiting to plants and microbes. Transformations of nitrogen-containing molecules into different chemical forms in soil can regulate whether it is retained in ecosystems to be available for plant and microbial uptake or lost from ecosystems to contribute to water and air pollution. This project will improve understanding of when, where, and why different nitrogen-containing molecules are produced and consumed in forest soils. This project has broad societal implications because of the potential to moderate the effects of human-induced nitrogen inputs on ground- and surface water pollution from soil leaching and gas emission. Knowledge gained from this research can guide future studies to develop best management practices to retain nitrogen in agroecosystems to improve crop yields while reducing nutrient runoff and release from fertilizer use. The project supports an early career female scientist as the principal investigator and contributes to the training of a female graduate student. All project personnel will be involved in the mentoring of undergraduate and high school students in research experiences, including recruiting students who are members of under-represented groups in science and developing a new a short course on Soil Biology for the Illinois 4-H Summer Academy, serving a variety of high school students.
The process of dissimilatory nitrate reduction to ammonium (DNRA), carried out by soil microbes, plays a pivotal role in regulating ecosystem nitrogen retention versus loss because nitrate is a more mobile nitrogen-containing molecule than ammonium. By converting nitrate to ammonium, DNRA retains nitrogen in ecosystems to support plant productivity, reduces nitrate loss to ground- and surface waters, and competes with the process of denitrification to decrease gaseous dinitrogen and nitrous oxide losses. Despite its importance, DNRA is generally disregarded and understudied in non-flooded ecosystems on land because of the misconception that the process is restricted to conditions typically found in flooded environments. State-of-the-art stable isotope and molecular techniques will be used to unravel the existing paradoxical understanding of DNRA by answering the following the questions: (1) Where can DNRA occur, and why? (2) which microorganisms are responsible for DNRA? and (3) How important is DNRA relative to denitrification as a fate of nitrate, and what controls the competition between these two pathways? The study will utilize sites across the NSF Long-Term Ecological Research (LTER) and Critical Zone Observatory (CZO) Networks. Sites will be selected to represent a range in edaphic properties, climate, and microbial community structure that can control the environmental and genetic potential for DNRA. Laboratory soil microcosm experiments will be used to determine how oxygen and nitrite affect rates of DNRA and other nitrogen transformation processes that interact with DNRA, such as nitrification and denitrification. Stable isotope tracer and pool dilution techniques will be used to measure gross rates of these processes. Illumina sequencing, quantitative polymerase chain reaction, and proteomic analyses will be used to interrogate which microbes perform DNRA and why. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/89999
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| Appears in Collections: | 全球变化的国际研究计划
科学计划与规划
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| Recommended Citation: | |
Wendy Yang. Unraveling the paradox of dissimilatory nitrate reduction to ammonium in upland soils. 2017-01-01.
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