Carbon Storage in Peatlands within an Ever-changing Environment - Soil Organic Matter Dynamics in the Context of Active Volcanism

• Main Author: Möckel, Susanne Claudia
• Other Authors: Guðrún Gísladóttir, Líf- og umhverfisvísindadeild (HÍ), Faculty of Life and Environmental Sciences (UI), Verkfræði- og náttúruvísindasvið (HÍ), School of Engineering and Natural Sciences (UI), Háskóli Íslands, University of Iceland
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: University of Iceland, School of Engineering and Natural Sciences, Faculty of Life and Environmental Sciences 2022
• Subjects: Peatlands; carbon storage; aeolian deposits; andic soil properties; Doktorsritgerðir; Kolefnisbinding; Mýrlendi; Mýrar; Iceland
• Online Access: https://hdl.handle.net/20.500.11815/3593

In the wake of increasing awareness of global warming, peatland conservation and restoration receive impetus by efforts to sequester carbon. Peatlands comprise a significant component of the global carbon cycle as they store up to 30% of global soil carbon. Carbon accumulation in Histosols, the most common organic soils of peatlands, is usually directed by hydrology and vegetation characteristics and the chemical composition of organic carbon. Mineral soil constituents, an important contributor for carbon accumulation and stability in mineral soils, are usually not considered important in Histosols. However, there is a growing body of evidence regarding the importance of mineral material in the volcanic ejecta for the carbon dynamics of peatlands in volcanic regions. Windborne volcanic ejecta certainly affect Histosols in Iceland. The island is one of the most active volcanic places in the world, and amongst the most dynamic of aeolian environments due to strong winds and a globally unmatched extent of volcaniclastic deserts. The aim of this PhD thesis was to investigate carbon dynamics in Icelandic Histosols under the varying impact of windborne mineral material. The research provides evidence for the co-importance of vegetation and carbon characteristics, and mineral soil constituents, for carbon dynamics in Icelandic peatlands. Particularly interesting is the positive relationship between minerals like allophane and ferrihydrite and certain carbon groups as well as shifts in carbon structure and stability around thick tephra deposits. This should be taken into consideration in projections of the effects of pressure such as by climate change and drainage on carbon cycling within peatland ecosystems. Á undanförnum árum hefur vitund almennings um loftslagshlýnun aukist. Í tengslum við það hefur verndun og endurheimt mýra til þess að auka bindingu kolefnis notið vaxandi meðbyrs. Mýrar, eða nánar tiltekið mómýrar, geyma allt að 30% kolefnis jarðvegs á heimsvísu og eru því mikilvægur hlekkur í kolefnishringrás. ...