The Boreal Nitrogen Gap: Size, fate and impacts of nitrogen fixation in Fennoscandia forest ecosystems

北方氮缺口：Fennoscandia 森林生态系统固氮的规模、命运和影响

• 批准号: NE/I027037/1
• 负责人: Nicholas Ostle
• 金额: $ 8.4万
• 依托单位: NERC CEH (Up to 30.11.2019)
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2012
• 资助国家: 英国
• 起止时间: 2012 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FI027037%2F1
• 关键词: Boreal; Nitrogen; Gap; Size; fate

Nitrogen is a primary limiting nutrient in high boreal and subarctic forest ecosystems, unfortunately, our understanding of fundamental N cycling processes in these oligotrophic environs remains limited which in turn hinders our ability to effectively predict ecosystem carbon (C) turnover and greenhouse gas emissions. Over the past 10 years we have elucidated a major N input in high boreal and subarctic ecosystems (1, 2), specifically we described the occurrence of an association between cyanobacteria and the ubiquitous and dominant feathermosses Pleurozium schreberi and Hylocomium splendens (3, 4). These two mosses act as the primary sources of biologically fixed N in subarctic and boreal forest systems and are also important in Arctic alpine tundra ecosystems (5). Although we have developed a clear picture of the quantity of N fixed by this association (6), our understanding of the pathway for N release into the ecosystems from the feathermosses remains greatly incomplete. A thorough understanding of these pathways will lead to a better understanding of C cycling processes at high latitudes and benefit a range of researchers from botanists, to ecologists, to ecosystem modellers.In this proposal we put forth several compelling hypotheses to further our understanding of fundamental processes in the N cycle of boreal Scots pine ecosystems and advance our general knowledge of the ecology of the feathermoss-cyanobacterial association in boreal forests of northern Sweden. To date most of our understanding of this association has surrounded field studies regarding the ecology of the feathermosses, little effort has been made to link the association to the belowground nutrient cycles and microbial community. Studies have been designed to address the following objectives: The four primary objectives of this proposed research are therefore to: (1) Assess the relationship between feathermoss N fixation and site productivity along natural fertility gradients and N deposition gradients in northern Fennoscandia; (2) Determine the portion of fixed N that remains in an organic form in moss detritus and the role of disturbance in liberating this N; (3) Evaluate the role of mycorrhizas in the transfer of N (amino acid and peptide N) from feather mosses to plants; (4) Evaluate the relationship between fixed N and forest floor CO2, CH4, and N2O fluxes across N enrichment gradients (i.e. N deposition gradient and fire-chronosequence). Experiments will be conducted on established field sites in northern Sweden including a fire chronosequence to address change in N turnover with natural forest succession; a total of five natural fertility gradients to assess the influence of variable N and P limitation on N fixation, turnover and greenhouse gas emissions; and an anthropogenic N deposition gradient from southern to northern Sweden along which we will assess the influence of increased N deposition on N fixation, turnover and loss. These findings will have significant implications for those studying ecosystem processes at high latitudes including N fixation, N turnover, C fixation, and greenhouse gas emissions. It is our intent to work these results into existing biogeochemistry models that are designed to predict linked C and N dynamics as related to productivity and greenhouse gas emissions.Literature Cited1. T. H. DeLuca, O. Zackrisson, M.-C. Nilsson, A. Sellstedt, Nature 419, 917 (2002).2. O. Zackrisson, T. H. DeLuca, M.-C. Nilsson, A. Sellstedt, L. Berglund, Ecology 85, 3327 (2004).3. O. Zackrisson, T. H. DeLuca, F. Gentili, A. Sellstedt, A. Jäderlund, Oecologia In Press, (2009).4. F. Gentili, M. C. Nilsson, O. Zackrisson, T. H. DeLuca, A. Sellstedt, Journal of Experimental Botany 56, 3121 (2005).5. T. H. DeLuca, O. Zackrisson, Plant and Soil 294, 147 (2007).6 T. H. DeLuca, O. Zackrisson, M.-C. Nilsson, M. J. Gundale, Science 320, 1181 (2008).

不幸的是，氮是高北极和亚北极森林生态系统中的主要限制，我们对少突的N循环Rocesses的理解在过去10年中促进了生态系统碳（C）NOUCE NOUCE NOUCE NOUSE AP APUTIONS，这使得在少突的少突。在高北极和亚北极生态系统中（1，2）蓝细菌与无处不在的社会和主要的featermosesses pleurozium schreberi和hylocomium splendens（3，4）。也是Inrcine Alpine RA生态系统（5）可以更好地了解高纬度的自行车过程，并使从植物学家，生态学家再到生态系统建模器的一系列研究人员受益。在这项提议中，我们提出了几个令人信服的假设，以进一步了解我们对周期scots f Boreal Scine Pine pine foreal Scine中的基本过程的理解迄今为止，我们的大部分有关专长的生态学的研究，我们的大部分研究都没有努力将我们的大部分研究与地下营养周期和微生物群落联系起来，迄今为止，我们的大部分研究都没有努力。 Beathermoss N固定和现场生产力自然生育率梯度和北部的fennoscandia在苔藓碎屑中的作用；瑞典北部的沉积梯度和火式的田野。 And An Anthropogenic N Deposition Gradient from SoutherN to Nortern Sweden Along Which We Will Assess of Increaseed N Deposit on N N N N N N N N N N N fixation, turnover and loss. These findings will have significant implications for those studying ecosystem processes at high latitudes including N fixation, N turnover, C固定和温室气体排放是我们的目的是将这些结果纳入现有的生物地球化学模型，这些模型旨在预测与生产力气体发射有关的链接的C和N动力学。 2002）.2。 F. Gentili，M。Nilsson，O。H。Deluca，A.Sellstedt，实验植物学杂志，56，3121（2005）。 C. Nilsson，M。J. Gundale，Science 320，1181（2008）。

项目成果

Can digital image classification be used as a standardised method for surveying peatland vegetation cover?

• DOI: 10.1016/j.ecolind.2015.11.035
• 发表时间: 2016-09-01
• 期刊: ECOLOGICAL INDICATORS
• 影响因子: 6.9
• 作者: Baxendale, Catherine L.;Ostle, Nick J.;Ward, Susan E.
• 通讯作者: Ward, Susan E.

Soil Methane Sink Capacity Response to a Long-Term Wildfire Chronosequence in Northern Sweden.

• DOI: 10.1371/journal.pone.0129892
• 发表时间: 2015
• 期刊: PloS one
• 影响因子: 3.7
• 作者: McNamara NP;Gregg R;Oakley S;Stott A;Rahman MT;Murrell JC;Wardle DA;Bardgett RD;Ostle NJ
• 通讯作者: Ostle NJ

Vascular plants promote ancient peatland carbon loss with climate warming.

随着气候变暖，维管束植物会促进泥炭地的碳流失。

• DOI: 10.1111/gcb.13213
• 发表时间: 2016-05
• 期刊: Global change biology
• 影响因子: 11.6
• 作者: Walker TN;Garnett MH;Ward SE;Oakley S;Bardgett RD;Ostle NJ
• 通讯作者: Ostle NJ

Warming effects on greenhouse gas fluxes in peatlands are modulated by vegetation composition.

• DOI: 10.1111/ele.12167
• 发表时间: 2013-10
• 期刊: Ecology letters
• 影响因子: 8.8
• 作者: Susan E. Ward;N. Ostle;S. Oakley;H. Quirk;P. Henrys;R. Bardgett

Vegetation exerts a greater control on litter decomposition than climate warming in peatlands.

• DOI: 10.1890/14-0292.1
• 发表时间: 2015
• 期刊: Ecology
• 影响因子: 4.8
• 作者: Susan E. Ward;K. Orwin;K. Orwin;Nick Ostle;Maria J. I. Briones;B. Thomson;R. Griffiths;S. Oakley;H. Quirk;R. Bardgett;R. Bardgett