Towards improved estimation of carbon balance in a low-Arctic mire: a micrometeorological eddy covariance approach to methane flux characterization.

改进低北极泥沼中碳平衡的估计：甲烷通量表征的微气象涡流协方差方法。

• 批准号: NE/F010222/1
• 负责人: Robert Baxter
• 金额: $ 7.93万
• 依托单位: Durham University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FF010222%2F1
• 关键词: Towards; improved; estimation; carbon; balance

The climate is warming. The Arctic regions of the world have been shown to be warming at a rate faster than any other region on earth. These high northern latitude regions may play a critical role in determining the global impacts of climatic change because they cover a significant proportion of the earth's surface in the northern hermisphere and act as a major carbon sink, currently storing some 11% of the earth's carbon, locked away in the organic soils and peat of Arctic tundra and extensive mire sytems that are representative of these Arctic regions. Thus it is vital that we better understand the factors that currently determine the balance, and exchange of carbon between land surface and atmosphere so as to better predict the likely consequences of continued warming of the Arctic. However, these high latitude regions remain data sparse, not only in terms of spatial coverage of data, but perhaps as, or more, importantly, in terms of temporal coverage, with still relatively few data sets available spanning extended periods of the annual cycle. This is particularly the case in terms of carbon in the form of methane. Methane is a powerful greenhouse gas that accounts for about 20% of the increase in global radiative forcing since the pre-industrial era. Wetlands play an important dual role in the global carbon cycle, being both the largest natural methane source and a large net carbon sink (that is that it locks away more carbon dioxide from the atmosphere than it releases to it). About 30% of global wetlands are located in northern Eurasia; many throughout the Arctic and sub-Arctic regions. Quantifying the potential impacts of global warming, and any positive feedback, requires models that represent the landscape through both space and through time. Such models must be underpinned by ecosystem studies that will provide the data necessary to achieve adequate representation of landscape processes and how they vary through space and time. The present proposal, linking ecosystem scientists at Durham and Stirling having expertise in measurement of methane concurrently at a range of spatial scales, with micrometeorological and modelling expertise at Edinburgh, seeks to provide such key data related to methane flux from an Arctic mire in N Finland, so as to obtain estimates of carbon sinks and sources at the regional scale of northern Finland. We propose to use the understanding gained, and the models developed, to better predict potential future regional methane fluxes. The approach we will undertake is that of methane measurement by the eddy covariance technique (a chamberless technique for measuring methane across a portion of a landscape without using artificial chamber approaches which, by their very use, impact upon the vegetation/soils being sampled). The technique allows in integration of fluxes from the various vegetation and soil assemblages that characterise the heterogeneous surface of Arctic mire ecosystems. The key advantage here is a continous record of CH4 flux between land surface and atmosphere for an extended period (ca. 4 week campaigns at different times of the year, in this instance). Key strengths of the current proposal are: the commitment of personnel and equipment for extended periods to allow methane flux measurements to be made without the unwanted, confounding inter-annual variation that has been encountered in some previous studies; and the particularly high added value that it offers because it builds directly upon, and is complemented by, ongoing NERC-funded research.

气候正在变暖。北极地区的变暖速度比地球上任何其他地区都要快。这些北纬高纬度地区可能在决定气候变化的全球影响方面发挥关键作用，因为它们覆盖了北半球地球表面的很大一部分，是一个主要的碳汇，目前储存了约11%的地球碳，被锁在北极冻土带的有机土壤和泥炭中，以及代表这些北极地区的广泛的沼泽系统中。因此，至关重要的是，我们要更好地了解目前决定陆地表面和大气之间碳平衡和碳交换的因素，以便更好地预测北极持续变暖可能带来的后果。然而，这些高纬度地区的数据仍然稀少，不仅在数据的空间覆盖方面，而且更重要的是，在时间覆盖方面，仍然有相对较少的数据集可以跨越较长的年周期。以甲烷形式存在的碳尤其如此。甲烷是一种强大的温室气体，自前工业化时代以来，它占全球辐射强迫增长的20%左右。湿地在全球碳循环中扮演着重要的双重角色，既是最大的天然甲烷来源，又是一个巨大的净碳汇（也就是说，它从大气中吸收的二氧化碳比向大气释放的二氧化碳要多）。全球约30%的湿地位于欧亚大陆北部；许多分布在北极和亚北极地区。量化全球变暖的潜在影响，以及任何积极的反馈，需要能够代表时空景观的模型。这些模型必须以生态系统研究为基础，这些研究将提供必要的数据，以充分反映景观过程及其在空间和时间上的变化。目前的提案将达勒姆和斯特林的生态系统科学家与爱丁堡的微气象和建模专家联系在一起，他们在一系列空间尺度上同时测量甲烷，旨在提供芬兰北部北极沼泽甲烷通量的关键数据，从而获得芬兰北部区域尺度上碳汇和碳源的估计。我们建议利用所获得的认识和开发的模型来更好地预测未来潜在的区域甲烷通量。我们将采用的方法是通过涡流相关技术测量甲烷（一种无室技术，用于测量一部分景观中的甲烷，而不使用人工室方法，因为人工室方法的使用会对正在采样的植被/土壤产生影响）。该技术允许整合各种植被和土壤组合的通量，这些通量是北极沼泽生态系统异质性表面的特征。这里的关键优势是对陆地表面和大气之间CH4通量的长时间连续记录（在这种情况下，在一年的不同时间约为4周的活动）。当前建议的主要优点是：承诺长期投入人员和设备，以便在进行甲烷通量测量时不出现以往一些研究中遇到的不需要的、令人混淆的年际变化；以及它提供的特别高的附加值，因为它直接建立在正在进行的nerc资助的研究之上，并得到了补充。

项目成果

Quantifying landscape-level methane fluxes in subarctic Finland using a multiscale approach.

• DOI: 10.1111/gcb.12975
• 发表时间: 2015-10
• 期刊: Global change biology
• 影响因子: 11.6
• 作者: Hartley IP;Hill TC;Wade TJ;Clement RJ;Moncrieff JB;Prieto-Blanco A;Disney MI;Huntley B;Williams M;Howden NJ;Wookey PA;Baxter R
• 通讯作者: Baxter R