Collaborative Research: Bedrock nitrogen and the Earth system: From geobiolgical mechanisms to climate change forecasts

合作研究：基岩氮和地球系统：从地球生物学机制到气候变化预测

• 批准号: 1411942
• 负责人: Kathleen Treseder
• 金额: $ 39.82万
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1411942&HistoricalAwards=false
• 关键词: Collaborative; Research; Bedrock; nitrogen; Earth

This project involves basic research of controls on nitrogen (N) weathering rates from bedrock across an array of terrestrial ecosystems and conditions ? spanning molecular techniques to global scale modeling. This study is motivated by the need to understand how biogeochemical cycles shape integrated Earth systems and has key implications for the pace and magnitude of climate change in the face of rising fossil fuel CO2 emissions. Bedrock lithologies house 99% of all reactive N compounds (i.e., all N forms other than N2 gas) on the planet; yet, the biogeochemical importance of this vast N reservoir has been overlooked. Textbook paradigms hold that new N enters ecosystems solely from the atmosphere via biochemical fixation or as N in deposition. However, these N input pathways are incapable of explaining the high rates of N accumulation observed for many terrestrial ecosystems, constituting a major unknown in the global N budget.As an alternative, the principal investigators suggest that the geosphere plays a major role in terrestrial N biogeochemistry ? imparting large effects on terrestrial carbon (C) cycling and climate change. They propose research to test the hypothesis that rocks of sedimentary origin represent a broadly significant source of N to the terrestrial biosphere. The research team includes geologists, biologists, pedologists, biogeochemists, and Earth system scientists. They will examine bedrock N weathering at molecular-, soil pedon-, watershed-, regional-, and global-scales. The proposed combination of state-of-the-art tools, involving lab, field, and modeling components, is novel. The molecular-scale research is focused on geobiology; it emphasizes ?rock-eating-fungi? effects on N weathering reactions, using controlled laboratory experiments and NanoSIMS (Nanometer-scale Secondary Ion Mass Spectrometry) across field sites. The soil pedon, watershed and regional analyses will estimate physical and chemical weathering of nitrogen across an array of lithologies, tectonic conditions, and climates. Linkages between weathering rates and the terrestrial nitrogen cycle will be empirically investigated regionally through measures of natural nitrogen stable isotopes, and carbon, nitrogen, and phosphorus chemistry. The global analyses will emphasize a new modeling scheme that couples a global biogeochemical model with a weathering model to scale the amount of rock-derived nitrogen that is available to store terrestrial carbon worldwide.

该项目涉及对氮（N）风化速率控制的基础研究，来自基岩的一系列陆地生态系统和条件？跨越分子技术到全球规模建模。这项研究的激励是由于需要了解生物地球化学周期如何塑造整合的地球系统，并在面对化石燃料CO2排放时对气候变化的速度和幅度具有关键意义。岩石岩石岩藏在地球上所有反应性N化合物（即除N2气体以外的所有N形式）中的99％；然而，这个广阔的水库的生物地球化学重要性被忽略了。教科书范式认为，新的N仅通过生化固定或沉积中的N进入大气中的生态系统。但是，这些N输入途径无法解释许多陆地生态系统观察到的N积累率的高率，这构成了全球N预算中的主要未知。对陆生碳（C）循环和气候变化产生很大的影响。他们提出了研究，以检验以下假设：沉积起源的岩石代表了陆地生物圈的氮的广泛重要来源。研究团队包括地质学家，生物学家，教育学家，生物地球运动员和地球系统科学家。他们将检查基岩N在分子，土壤踏板，分水岭，区域和全球尺度上的风化。涉及实验室，场和建模组件的最先进工具的组合是新颖的。分子规模的研究集中在地球生物学上。 它强调吗？ 使用受控实验室实验和纳米s（纳米尺度的次级离子质谱法）对N风化反应的影响。土壤踏板，分水岭和区域分析将估计氮在一系列岩性，构造条件和气候中的物理和化学风化。 风化速率与陆生氮周期之间的联系将通过自然氮稳定同位素以及碳，氮和磷化学的量度在区域进行经验研究。全球分析将强调一种新的建模方案，该方案将全球生物地球化学模型与风化模型融合在一起，以扩展可用于在全球范围内存储陆地碳的岩石衍生的氮量。