| 项目编号: | 1701748
|
| 项目名称: | Dissertation Research: Assessing the vulnerability of salt marsh carbon storage to nutrient enrichment using an integrated meta-omics framework |
| 作者: | Jennifer Bowen
|
| 承担单位: | Northeastern University
|
| 批准年: | 2017
|
| 开始日期: | 2017-06-01
|
| 结束日期: | 2018-05-31
|
| 资助金额: | 19878
|
| 资助来源: | US-NSF
|
| 项目类别: | Standard Grant
|
| 国家: | US
|
| 语种: | 英语
|
| 特色学科分类: | Biological Sciences - Environmental Biology
|
| 英文关键词: | salt marsh
; meta-omic
; doctoral dissertation improvement project
; carbon dioxide
; dissertation improvement grant
; organic matter decomposition
; much carbon
; nutrient filtration
; carbon storage capacity
; metabolic activity
; microbial metatranscriptome
; organic matter
; nutrient enrichment
; organic carbon quality
|
| 英文摘要: | As human populations increase, so will the demand for food. Nitrogen fertilizer production helps meet this need. However, adding excess nitrogen drastically alters natural habitats such as salt marshes and others that receive water as runoff from land. Coastal wetlands provide several ecosystem services, including nursery habitat for fish and birds, storm surge protection, and nutrient filtration. Prior studies suggest that excess nitrogen may increase decomposition in these sediments, resulting in faster degradation of complex organic matter to carbon dioxide. What controls these processes, and the micro-organisms responsible for them is not well understood. This doctoral dissertation improvement project will use controlled laboratory experiments to investigate the mechanisms behind the effect of added nitrogen on organic matter decomposition. This research will provide an in-depth analysis of the members of the salt marsh microbiome and their activities in marsh sediments. Data will provide insight into how salt marshes are responding to nitrogen fertilizer runoff, information that is essential for the adaptive management of coastal wetland systems and their response to environmental change.
This doctoral dissertation improvement project will use controlled flow through reactor systems to investigate the mechanistic effect of nitrate on microbial decomposition of salt marsh sediment organic matter. We hypothesize that, because nitrate is a favorable electron acceptor in heterotrophic, microbial respiration, it can promote oxidation of organic matter that would otherwise remain unprocessed. Current biogeochemical data indicate a significant increase in microbial respiration, particularly denitrification, in response to nitrate addition, with the most pronounced effect in deep sediments ranging from 150 to 200 years old. This is significant, because organic matter at this depth is typically thought to be more resistant to microbial degradation, which means that the capacity of salt marshes to store carbon may lessen with eutrophication. To further assess these results, we need to gain a better understanding of the microbial consortia responsible for organic matter decomposition. Microbial activity plays a critical role in controlling how much carbon is decomposed; though we know little about salt marsh sediment microbiome structure and function, and how it may change in response to nitrate addition. Accordingly, this dissertation improvement grant will contribute to existing data by taking an integrated 'meta-omics' approach. To complement flow through reactor experiments, the microbial genetic underpinnings of organic matter decomposition under conditions of nutrient enrichment will be investigated using metagenomics, and the metabolic activity of these microbial players will be assessed by measuring the expression of the microbial metatranscriptome. These data have the potential to reveal novel microbial lineages from deep salt marsh sediment, and draw unique linkages between microbial gene expression patterns and changes in organic carbon quality. Successful integration of these meta-omics approaches with existing geochemical rate measurements will vastly improve our understanding of the role of microbes in organic matter decomposition, and potentially allow for a better predictive understanding for how carbon storage capacity in salt marshes will respond to future nitrogen loading. |
| 资源类型: | 项目
|
| 标识符: | http://119.78.100.158/handle/2HF3EXSE/90080
|
| Appears in Collections: | 全球变化的国际研究计划
科学计划与规划
|
|
There are no files associated with this item.
|
| Recommended Citation: | |
Jennifer Bowen. Dissertation Research: Assessing the vulnerability of salt marsh carbon storage to nutrient enrichment using an integrated meta-omics framework. 2017-01-01.
|
|
|