RUI: Post-fire Nitrogen Cycling in Boreal Bogs - Critical Unknowns Explored

RUI：北方沼泽火灾后的氮循环——探索关键的未知因素

• 批准号: 1256985
• 负责人: R. Kelman Wieder
• 金额: $ 117万
• 依托单位: Villanova University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-03-15 至 2018-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1256985&HistoricalAwards=false
• 关键词: RUI; Post; fire; Nitrogen; Cycling

This research is structured around a novel conceptual framework for how nitrogen (N) cycling in boreal bogs changes as a function of both time-since-fire and experimentally augmented N. Bog sites of different ages (time since the most recent fire) will receive elevated N inputs in simulated rainfall. New insights will be gained into: the importance of biological N2-fixation as a newly recognized major input of N into these bogs; the role of Sphagnum mosses, which cover the bog surface and are the major contributors to ongoing peat accumulation, as the gatekeepers of newly acquired N from either N2-fixation or rain and snow; and the linkages between N inputs and the ability of bogs to sequester both N and carbon (C) in the accumulating peat.Boreal peatlands cover only 3-4% of the Earth's land surface, yet store 25-30% of the world's soil C and 9-16% of the world's soil N in peat. Peatlands represent an ongoing net sink for atmospheric carbon dioxide. Bogs of western Canada persist at the dry end of the climatic gradient across which peatlands exist, and hence are especially sensitive to ongoing climate changes that include increasing temperature, as well as increasing wildfire frequency and severity. Further, in western Canada, atmospheric N deposition historically has been low, but is increasing because of N emissions from oil sands development in northern Alberta. Clarifying the linkages between N and C cycling in western Canadian bogs will enhance the ability to predict how N and C storage in peat may be influenced by ongoing climate change. The research will support graduate and undergraduate thesis students; the PIs will teach a Peatland Ecology course at the Meanook Biological Research Station, Alberta, Canada, in years 2 and 4 of the project.

这项研究是围绕一个新颖的概念框架构建的，该框架是北方沼泽中的氮（N）循环如何随着时间 - 摩之火和实验增强的不同年龄增强的N. bog位点的变化而变化（自最近火灾以来的时间（自最近火灾以来）将获得升高的N输入。 新见解将获得：生物N2固定作为新沼泽中新认可的主要投入的重要性；泥石苔藓的作用覆盖了沼泽表面，是持续的泥炭积聚的主要因素，因为从N2固定或雨水和雨水中获得了N的守门人；以及n个投入和沼泽在累积的泥炭中隔离N和碳（C）的能力之间的联系。BorealPeatlands仅覆盖地球陆地表面的3-4％，但在世界土壤中的25-30％却占了25-30％的土壤C和9-16％的泥炭中土壤N。 泥炭地代表了一个正在进行的大气二氧化碳的净水槽。 加拿大西部的沼泽持续存在在存在泥炭地的气候梯度的干燥端，因此对持续的气候变化特别敏感，包括升高温度以及野火频率和严重程度的增加。 此外，在加拿大西部，大气n在历史上的沉积较低，但由于艾伯塔省北部油砂的n排放量增加。 澄清西部加拿大沼泽中N和C骑自行车之间的联系将增强预测泥炭中的N和C储存的能力，如何受到持续的气候变化的影响。 该研究将支持毕业生和本科论文专业的学生； PIS将在该项目的第2年和4年内在加拿大艾伯塔省艾伯塔省的卑鄙的生物学研究站教授泥炭地生态学课程。