Linking Microbial Physiology with Carbon Transformations in Peatlands Under Land Use Change

将微生物生理学与土地利用变化下泥炭地的碳转化联系起来

• 批准号: 2445868
• 金额: --
• 依托单位: University of Aberdeen
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2445868
• 关键词: Linking; Microbial; Physiology; Carbon; Transformations

Significant amount of carbon is stored in soils, particularly in peatlands. Increasing food and energy needs have led to intensive land use practices that deplete soil organic carbon (SOC) stores. In Scotland, drainage for agriculture and commercial forestry in its vast swathes of peatlands has caused their degradation with significant loss of carbon. Their recent restoration has led to the return of SOC sequestration, and associated climate benefits, but the underlying carbon cycling mechanisms have not been clearly understood. This mechanistic understanding is required to better predict and manage soil processes to maintain or even enhance SOC storage in peatlands while economising land-use.Microorganisms are critical in this regard because their growth and activity largely control the fate of recent plant carbon inputs, as well as the stability of assimilated microbial carbon. The balance between the rate of microbial decomposition and stabilisation of organic carbon in soil can shift under altered environmental conditions. In peatlands, water-logged conditions, anaerobiosis and acidity limit microbial growth and decomposition that consequently causes preservation of organic carbon. Peatland degradation through drainage removes the factors causing organic carbon preservation thus leading to SOC loss through microbial decomposition. Restorative approaches aim at reversing these effects thereby limiting the loss of SOC; however, the exact hydrological, chemical and biotic mechanisms and their inter-dependencies are poorly understood.This project aims at understanding the effects of peatland degradation and subsequent restoration on microbial physiological processes and their consequences on soil carbon transformations. Project will rigorously test the hypotheses that microbial growth, activity and decomposition is limited by acidity and anaerobiosis in peatlands; and that peatland degradation causes increased microbial growth and consequently decomposition of peat organic matter. We will have access to multiple peatland sites under various land use types across Scotland to test the hypotheses. The goal is to assess microbial carbon cycling functions like growth rate, carbon use efficiency, resource breakdown and uptake, maintenance and stress tolerance. These community traits will be quantified using a combination of stable isotope tracing and shot-gun metagenomics, and their fingerprints in driving changes in SOC will be assessed using chemical molecular tools like FTIR.Using stable isotope tracers, we will measure microbial incorporation of carbon into biomass and loss through respiration to quantify community-level traits like carbon use efficiency, growth rate and specific respiration across land use types. Analytical facilities for gas, solid, soil solution and compound-specific 13C isotope ratio mass spectrometry (IRMS) including cavity ring-down spectrometry (CRDS) at University of Aberdeen (UoA) and James Hutton Institute (JHI) are unique and training will be provided by the supervisory team. Whole genome shot-gun metagenomics will be used to investigate functions of peatland microbial communities under different land use. The goal here will be to extract physiological traits of microbes that are dominant in soils under different land use.The Centre for Genome Enabled Biology and Medicine (www.abdn.ac.uk/genomics) at UoA houses DNA sequencing platforms like Illumina NextSeq500 and Oxford Nanopore GridION which will be available to the project including training in molecular methods and bioinformatics. Chemical analysis of the extant organic matter will be used to characterise peatland organic matter at the molecular level using FTIR. Once we are able to form a link between microbial traits and carbon cycling processes, we will be able to use the combined knowledge to ascertain the efficacy of restorative practices in changing microbial physiology aimed at regaining and sequestering carbon in peatlands.

大量碳存储在土壤中，尤其是泥炭地。增加的食物和能源需求导致了耗尽土壤有机碳（SOC）商店的密集土地使用实践。在苏格兰，在大量的泥炭地中，农业和商业林业的排水导致了它们的降解，并大幅损失了碳。他们最近的恢复导致了SOC隔离的返回和相关的气候益处，但是尚未清楚地了解了潜在的碳循环机制。需要这种机械理解才能更好地预测和管理土壤过程，以维持甚至增强泥炭地的SOC储存，同时又可以加强土地利用。在这方面，微生物至关重要，因为它们的生长和活性在很大程度上控制了最近的植物碳输入的命运，以及同化的微生物碳的稳定性。在环境条件改变的情况下，微生物分解速率与有机碳稳定之间的平衡可能会改变。在泥炭地，水含量的条件，厌氧菌和酸度限制了微生物的生长和分解，从而导致保存有机碳。泥炭地通过排水降解去除了导致有机碳保存的因素，从而导致通过微生物分解导致SOC损失。恢复性方法旨在逆转这些效果，从而限制SOC的丧失；然而，确切的水文，化学和生物机制及其相互依存性的理解很少。该项目旨在了解泥炭地降解及其随后恢复对微生物生理过程及其对土壤碳转化的影响的影响。项目将严格检验微生物生长，活性和分解受到泥炭地的酸度和厌氧菌病的限制。泥炭地降解会导致微生物的生长增加，从而导致泥炭有机物的分解。在苏格兰各种土地利用类型下，我们将可以使用多个泥炭地遗址来检验假设。目的是评估微生物碳循环功能，例如生长速率，碳使用效率，资源分解和吸收，维护和压力耐受性。这些社区性状将通过稳定的同位素追踪和射击枪型宏基因组的结合来量化，以及它们在推动SOC变化方面的指纹构成将使用FTIR等化学分子工具进行评估类型。气体，固体，土壤溶液和化合物特异性13C同位素比率质谱（IRMS）的分析设施，包括阿伯丁大学（UOA）（UOA）和詹姆斯·赫顿研究所（JANS HUTTON Institute（JHI））的腔体铃声光谱法（CRDS）是独特的，并且将由主管团队提供培训。整个基因组射击岩石组学将用于研究不同土地使用下泥炭地微生物群落的功能。这里的目的是提取在不同土地使用下在土壤中占主导地位的微生物的生理特征。启用基因组的生物学和医学中心（www.abdn.ac.uk/genomics）在UOA中包含DNA测序平台，例如Illumina NextSeq500和Oxford Nananopore Gridion，包括该项目，包括该项目以及Bio to nocult to the Soleters and Molecin ins Molecins and Soles soparts and Sorect and Moleciont。现有有机物的化学分析将用于使用FTIR在分子水平上表征泥炭地有机物。一旦我们能够在微生物性状和碳循环过程之间形成联系，我们将能够利用合并的知识来确定恢复性实践在改变微生物生理学方面的疗效，旨在恢复泥炭地中的碳。