| 项目编号: | 1456528
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| 项目名称: | Collaborative Research: LTREB: Soil Warming and Forest Ecosystem Feedbacks to the Climate System |
| 作者: | Jerry Melillo
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| 承担单位: | Marine Biological Laboratory
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| 批准年: | 2014
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| 开始日期: | 2015-05-01
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| 结束日期: | 2020-04-30
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| 资助金额: | USD345520
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| 资助来源: | US-NSF
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| 项目类别: | Continuing 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: | som
; soil respiration
; harvard forest
; soil
; experiment
; soil warming experiment
; long-term soil response
; future climate
; soil carbon
; ambient soil temperature
; soil process
; long-term warming
; soil organic matter
; deciduous forest
; mature eastern forest
; ecosystem process
; soil response
; climate system
; earth system model
; temperature
; soil temperature
; plant-soil interaction
; soil biogeochemistry
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| 英文摘要: | Soils store at least three times more carbon in soil organic matter (SOM) than either the atmosphere or vegetation. The response of SOM to increasing temperature is an important aspect of the interactions between ecosystems and climate. If increasing temperatures cause soil carbon to be transferred to the atmosphere, the result would be a self-reinforcing (positive) feedback to the climate system, with warming leading to more warming. Despite the potential importance of this feedback, there is currently an incomplete understanding of the mechanisms that affect the temperature sensitivity of SOM. This project will continue a long running soil warming experiment at Harvard Forest which is currently in its third decade. The experiments use heated cables to warm the soil in a mature eastern forest. To date, the results of this experiment have shown dynamic responses of SOM to temperature over time. This project will continue to study and monitor long-term soil responses to warming to advance the scientific understanding of how temperature controls decomposition of SOM on a decadal time scale. The results will improve the representation of soil processes in the Earth system models that are used to project future climate.
Ongoing field warming experiments in the deciduous forest stands at Harvard Forest have imposed 5oC above ambient soil temperatures at three replicated sites for 8, 11 and 23 years, which now correspond to three distinct phases of CO2 emissions in the longest running experiment. There was an initial increase in soil respiration in response to warming in the first decade, followed by no response, and finally another period of higher soil respiration in the heated plots in the last 8 years. The chronosequence of the three warming experiments offers a unique opportunity to understand how increasing soil temperatures affect soil biogeochemistry, plant-soil interactions, and microbial community composition over time. The research has three major components: 1) continuation of core measurements of carbon and nitrogen stocks and fluxes; 2) short-term temperature manipulations combined with measurements of key indicators of biogeochemical and microbial community changes; and 3) targeted process-level measurements that enhance a mechanistic understanding of soil responses to long-term warming. The project will measure the isotopic composition of carbon and nitrogen, the chemical composition of SOM, and microbial community composition along the chronosequence. The soil warming experiments will continue to operate as an open facility for students and researchers nationwide to study the long-term effects of warming on ecosystem processes. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/94723
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| Appears in Collections: | 影响、适应和脆弱性
气候减缓与适应
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| Recommended Citation: | |
Jerry Melillo. Collaborative Research: LTREB: Soil Warming and Forest Ecosystem Feedbacks to the Climate System. 2014-01-01.
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