Global change processes in peatlands: A study of the microbiology and biogeochemistry of reactive nitrogen oxides

项目亮点：-新的研究揭示了英国泥炭地网络中活性氮氧化物（NOy）排放的重要性。了解泥炭地NOy对人类和更广泛的环境福祉至关重要。- 一个多机构的监督伙伴关系，连接到国家的最先进的仪器和机会，更广泛的合作，在资助泥炭地研究项目。- 实验室和现场经验的结合，从分子技术到现场痕量气体测量的技能概述：英国的泥炭地占土地覆盖面积的9.5% 1，目前正在经历快速变化，以应对环境刺激，如人类活动导致的大气氮（N）沉积增加。这些生态系统执行过多的功能，最重要的是充当有机物质（OM）的大型水库。研究表明，氮沉降可能会将这些有机质存量转化为温室气体源（CO2，CH 4）。2然而，迄今为止，很少有人关注增强的N沉积如何也会改变释放活性氮氧化物的N循环过程（NOy = NO，NO2，HONO）。活性氮氧化物的研究非常不足，可能会从泥炭地以高速率排放，尤其是在增加的N沉积下。NOy气体被归类为导致人类呼吸窘迫的空气污染物，也可以催化导致地面臭氧形成和植被破坏的反应。在更大的尺度上具有全球意义，因为它们控制着大气的氧化能力，温室气体的寿命以及直接和间接影响气候的二次气溶胶形成率。虽然NOy是硝化和反硝化的已知产物，但最近发现的涉及铁的过程（Feammox）被认为对这些生态系统中NOy的产生和排放极其重要。Feammox是一种微生物过程，通常发生在饱和土壤（如泥炭地）的缺氧条件下，其中铁氧化物可以作为电子受体，在没有氧气的情况下对N反应起关键作用。据认为，高达7%的N从厌氧土壤3 -6的损失可能是由Femmanox介导的，但估计是高度不确定的，由于缺乏，如果在这方面的研究。因此，有一个关键的需要（一）确定英国泥炭地的内在能力，以产生NOy，（二）探讨N-沉积在这些生态系统中的N-循环速率的影响，（三）区分的机制，其中N是转化泥炭地，特别注意微生物-铁介导的过程。

Project Highlights: - New research to unravel the significance of reactive nitrogen oxide (NOy) emissions from a network of UK peatland sites. Understanding peatland NOy is important for human and wider environmental well-being. - A multi-institute supervisory partnership linking to state-of-the-art instrumentation and opportunities for wider collaboration in funded peatland research projects. - A blend of laboratory and field experience, accessing skills ranging from molecular techniques to in-situ trace gas measurement Overview:Peatlands in the UK account for 9.5% of land cover1 and are currently experiencing rapid modifications in response to environmental stimuli such as increased atmospheric nitrogen (N) deposition sourced from human activity. These ecosystems perform a plethora of functions, none more critical than acting as large reservoirs of organic matter (OM). Research has demonstrated that N-deposition may transform these OM stocks into sources of greenhouse gases (CO2, CH4).2 However, to date much less attention has been paid to how enhanced N deposition may also change N-cycling processes that release reactive nitrogen oxides (NOy = NO, NO2, HONO).Reactive nitrogen oxides are greatly understudied and may be emitted at high rates from peatlands, especially under increased N-deposition. NOy gases are categorized as air pollutants causing respiratory distress in humans and can also catalyse reactions that lead to ground level ozone formation and vegetation damage. At larger scales are globally significant as they control the oxidative capacity of the atmosphere, the lifetime of greenhouse gases, and the rate of secondary aerosol formation that directly and indirectly affects climate. While NOy are known products of nitrification and denitrification, a recently identified process involving iron (Feammox) has been suggested as being extremely important for the production and emission of NOy in these ecosystems. Feammox is a microbial process that generally occurs under anoxic conditions of saturated soils such as peatlands, where iron oxides can act as an electron acceptor and play a critical role influencing N reactions in the absence of oxygen. It is suggested that up to 7% loss of N from anaerobic soils3-6 may be mediated by Femmanox but estimates are highly uncertain due to the paucity if research in this area. Thus, there is a critical need to (i) determine the intrinsic ability of UK peatlands to produce NOy, (ii) explore the influence of N-deposition on N-cycle rates in these ecosystems, and (iii) differentiate the mechanisms by which N is transformed in peatlands, paying particular attention to microbe-iron mediate processes.