Biogeochemical Alteration of Particulate Pyrogenic Organic Carbon (pyC)

<p>The resistance of plant derived pyrogenic organic carbon (<em>py</em>C) to abiotic and biotic means of degradation has led to increased interest in the role of <em>py</em>C as a potential carbon sink, as well as a strategy for sequestering atmospheric CO2 to mitigate excess carbon emissions. Though much research pertaining to the fundamental properties of <em>py</em>C degradation have been performed in a controlled lab setting, there has been very little work regarding <em>py</em>C degradation in a field setting where factors such as precipitation and temperature fluctuate seasonally. This work focuses on various degradation characteristics of two different types of plant-derived <em>py</em>C, placed in both a burned and unburned setting, over a study period of 1-year. We observed that the potential for DOC from outside sources to adsorb itself to the surface of <em>pyC</em> increases in fall and spring due to increases in leaf litter and increases in temperature, respectively. We also observed that the overall recalcitrance of pine-derived <em>pyC</em>s decreases with time and the overall recalcitrance of CG-derived pyCs increases with time, as different portions of the <em>pyC</em>s are utilized by microbes depending on the microbial community present. Finally, we observed that <em>pyC</em>s degrade differently in burnt and unburnt sites. Namely, a more specialized microbial community found in burnt sites is able to utilize pine <em>py</em>Cs faster than the microbial community found in unburned sites. However, this specialization leads to the opposite trend occurring for CG <em>py</em>Cs, in which degradation occurs more quickly in unburnt sites than in burnt sites.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Masters Thesis

Discipline thesis:degree_discipline

Geography and Geology

Year dc:date.available

2015

Author dc:creator

• Stuart, Jason Matthew

Contributors dc:contributor

• Omar R. Harvey
• Frank Heitmuller
• Kevin A. Kuehn

• Carbon
• Pyrogenic
• Recalcitrance
• Degradation
• Geochemistry
• Geology

Repository record dc:identifier

https://aquila.usm.edu/masters_theses/126

OAI identifier oai:identifier

oai:aquila.usm.edu:masters_theses-1132