Temperature Response of Methane and Carbon Dioxide Production in Arctic Fen Peat and Comparison to Seasonal Rates of Measured Methane Emission

• Other Authors: Ogles, Olivia Catherine (author), Chanton, Jeffrey P. (professor directing thesis), Spencer, Robert G. M. (committee member), Dewar, William K. (committee member), Florida State University (degree granting institution), College of Arts and Sciences (degree granting college), Department of Earth, Ocean, and Atmospheric Science (degree granting department)
• Format: Master Thesis
• Language: English
• Published: Florida State University 2023
• Subjects: Chemical oceanography; Climatic changes; Aquaculture; palsa; permafrost
• Online Access: https://repository.lib.fsu.edu/islandora/object/fsu%3A928016/datastream/TN/view/Temperature%20Response%20of%20Methane%20and%20Carbon%20Dioxide%20Production%20in%20Arctic%20Fen%20Peat%20and%20Comparison%20to%20Seasonal%20Rates%20of%20Measured%20Methane%20Emission.jpg

Permafrost is an area of ground which continually maintains temperatures below 0˚C and is found across arctic and sub-arctic regions, with 50% of the global soil carbon contained within permafrost storage banks (Trubl et al., 2016). In these high-latitude regions temperatures have risen 0.6˚C per decade over the last 30 years, a rise twice as fast as the global average (Schuur et al., 2015). The thawing of permafrost causes quantities of organic carbon to decompose via soil microbes, with permafrost regions containing twice as much carbon as currently resides in the atmosphere (Schuur et al., 2015). Permafrost thawing is common in Northern areas susceptible to environmental changes such as Stordalen mire, Sweden, where it is feared that the decomposition of permafrost could cause massive soil carbon degradation and the production of both methane (CH4) and carbon dioxide (CO2) causing dramatic elevations in CH4 emissions and the weakening of the landscape's carbon sink functionality. When frozen permafrost palsa regions thaw they transition into regions with higher water tables including bogs and wet fens. With this transition, CO2 uptake may increase and CH4 emissions rise (Holmes et al., 2022; Varner et al., 2022), increasing warming potential across Northern areas like Stordalen and accelerating positive feedback loops driven by climate warming (McCalley et al., 2014). Centrally, the first objective of this research was to define the effect temperature increase has on greenhouse gas production (CH4 and CO2) due to anaerobic heterotrophic soil respiration across fen-type peatlands. For this study, anaerobic incubations of fen peat were conducted at temperatures ranging from 1℃ to 25℃ on two depths of peat, 9-19 cm and 28-35 cm. It was found that as temperatures increased both CH4 and CO2 production increased exponentially, with CH4 production exhibiting a Q10 of around 7 while anaerobic CO2 production had a Q10 of roughly 2. The second objective of this thesis was to scale these measurements of methane ...