Physical Sciences and Mathematics Commons^™

Impacts Of Wildfire And Landscape Factors On Organic Soil Properties In Arctic Tussock Tundra, Jiaying He, Dong Chen, Liza K. Jenkins, Tatiana V. Loboda

Michigan Tech Publications

Tundra ecosystems contain some of the largest stores of soil organic carbon among all biomes worldwide. Wildfire, the primary disturbance agent in Arctic tundra, is likely to impact soil properties in ways that enable carbon release and modify ecosystem functioning more broadly through impacts on organic soils, based on evidence from a recent extreme Anaktuvuk River Fire (ARF). However, comparatively little is known about the long-term impacts of typical tundra fires that are short-lived and transient. Here we quantitatively investigated how these transient tundra fires and other landscape factors affected organic soil properties, including soil organic layer (SOL) thickness, soil …

Active Layer Thickness As A Function Of Soil Water Content, Leah K. Clayton, Kevin Schaefer, Michael Battaglia, Laura Bourgeau-Chavez, Jingyi Chen, Richard H. Chen, Albert Chen, Kazem Bakian-Dogaheh, Sarah L. Grelik, Elchin Jafarov, Lin Liu, Roger John Michaelides, Mahta Moghaddam, Andrew D. Parsekian, Adrian V. Rocha, Sean R. Schaefer, Taylor Sullivan, Alireza Tabatabaeenejad, Kang Wang, Cathy J. Wilson, Howard A. Zebker, Tingjun Zhang, Yuhuan Zhao

Michigan Tech Publications

Active layer thickness (ALT) is a critical metric for monitoring permafrost. How soil moisture influences ALT depends on two competing hypotheses: (a) increased soil moisture increases the latent heat of fusion for thaw, resulting in shallower active layers, and (b) increased soil moisture increases soil thermal conductivity, resulting in deeper active layers. To investigate their relative influence on thaw depth, we analyzed the Field Measurements of Soil Moisture and Active Layer Thickness (SMALT) in Alaska and Canada dataset, consisting of thousands of measurements of thaw depth and soil moisture collected at dozens of sites across Alaska and Canada as part …

Assessing Boreal Peat Fire Severity And Vulnerability Of Peatlands To Early Season Wildland Fire, Laura Bourgeau-Chavez, Sarah L. Grelik, Michael Billmire, Liza K. Jenkins, Eric S. Kasischke, Merritt R. Turetsky

Michigan Tech Publications

Globally peatlands store large amounts of carbon belowground with 80% distributed in boreal regions of the northern hemisphere. Climate warming and drying of the boreal region has been documented as affecting fire regimes, with increased fire frequency, severity and extent. While much research is dedicated to assessing changes in boreal uplands, few research efforts are focused on the vulnerability of boreal peatlands to wildfire. In this case study, an integration of field data collection, land cover mapping of peatland types and Landsat-based fire severity mapping was conducted for four early season (May to mid-June) wildfires where peatlands are abundant in …

Dissolved Organic Matter Movement Across Lake Superior’S Terrestrial-Stream-Coastal Interface, Karl M. Meingast

Dissertations, Master's Theses and Master's Reports

Dissolved organic matter (DOM) represents a carbon pool that can be easily translocated between ecosystems with the movement of water. This study examines the controls on DOM quantity and character delivered to Lake Superior primarily during the snowmelt period. We employed long-term stream dissolved organic carbon (DOC) data to determine quantity as well as absorption and fluorescence spectroscopy to analyze DOM structure. Our results indicate that an increasing trend in DOC concentrations, likely driven by decreases in acidity of precipitation, combined with slightly less annual runoff have resulted in relatively constant fluxes of DOM to Lake Superior. Additionally, our study …

Biogeochemical Response To Vegetation And Hydrologic Change In An Alaskan Boreal Fen Ecosystem, Danielle L. Rupp

Dissertations, Master's Theses and Master's Reports

Boreal peatlands store approximately one third of the earth’s terrestrial carbon, locked away in currently waterlogged and frozen conditions. Peatlands of boreal and arctic ecosystems are affected increasingly by shifting hydrology caused by climate change. The consequences of these relatively rapid ecosystem changes on carbon cycling between the landscape and the atmosphere could provide an amplifying feedback to climate warming. Alternatively, the advancement of terrestrial vegetation into once waterlogged soils could uptake carbon as a sink. Previous work suggests that fens will become an increasingly dominant landscape feature in the boreal. However, studies investigating fens, their response to hydrologic and …

Rock Magnetic Investigation Of The Michigan Basin Soils And Sediments Overlying The Oil-Bearing Silurian Pinnacle Reefs, Jake Tresnak

Dissertations, Master's Theses and Master's Reports

A relationship between the hydrocarbon migration and magnetic properties of near-surface sediments was investigated from several hundreds of samples collected over the hydrocarbon-bearing Silurian pinnacle reef belt of the Michigan Basin. The collected samples were investigated using several rock magnetic methods and optical microscopy. The investigation has not revealed a straightforward relationship between the magnetic susceptibility and hydrocarbon reservoirs within the reef belt; both anomalously high and low susceptibility values were observed. The elevated values are associated with newly formed magnetite in the form of spheroidal grains produced by hydrocarbon-related diagenesis while the extremely low susceptibilities may reflect dissolution of …

The Role Of Amino Acids In The Nitrogen Cycle Of Peatlands, Tia Scarpelli

Dissertations, Master's Theses and Master's Reports

Future release of carbon from peatlands in response to climate change may be impacted by nitrogen limitation. The current study considers the role of amino acids as a nitrogen source in peatlands. The total free amino acid (TFAA) concentration for peats ranged from 0-2.3 µM, and leucine was the primary contributor. The dominance of sedge or ericaceous shrub plant types did not significantly impact the TFAA pool. Ammonium concentrations were much greater than TFAA and nitrate concentrations. TFAA concentrations were greatest in spring and least in fall. The springtime maxima and summer decrease in concentrations were simulated in a modeling …

Effects Of Wildfire And Post-Fire Salvage Logging On Rill Networks And Sediment Delivery In California Forests, Will Olsen

Dissertations, Master's Theses and Master's Reports

Wildfires can increase soil erosion by orders of magnitude over rates in unburned forests and negatively impact aquatic resources. Rill erosion is a dominant erosion and sediment transport mechanism in burned forests, and hydrologically connected rills can form networks on burned hillslopes. At the swale scale (< 10,000 m²), little is known about how rill networks develop under different burn severities over time, their relationship with sediment yields, and the effect of post-fire salvage logging on rill networks and sediment yields.

The first study assessed rill networks and sediment yields in three burn severities in the inland Coast Range of …

Rapid Response Tools And Datasets For Post-Fire Modeling: Linking Earth Observations And Process-Based Hydrological Models To Support Post-Fire Remediation, Mary Ellen Miller, Michael Billmire, William J. Elliot, K. A. Endsley, P. R. Robichaud

Michigan Tech Research Institute Publications

Preparation is key to utilizing Earth Observations and process-based models to support post-wildfire mitigation. Post-fire flooding and erosion can pose a serious threat to life, property and municipal water supplies. Increased runoff and sediment delivery due to the loss of surface cover and fire-induced changes in soil properties are of great concern. Remediation plans and treatments must be developed and implemented before the first major storms in order to be effective. One of the primary sources of information for making remediation decisions is a soil burn severity map derived from Earth Observation data (typically Landsat) that reflects fire induced changes …

Evaluating The Long-Term Effects Of Logging Residue Removals In Great Lakes Aspen Forests, Michael I. Premer

Dissertations, Master's Theses and Master's Reports

Commercial aspen (Populus spp.) forests of the Great Lakes region are primarily managed for timber products such as pulp fiber and panel board, but logging residues (topwood and non-merchantable bolewood) are potentially important for utilization in the bioenergy market. In some regions, pulp and paper mills already utilize residues as fuel in combustion for heat and electricity, and progressive energy policies will likely cause an increase in biomass feedstock demand. The effects of removing residues, which have a comparatively high concentration of macronutrients, is poorly understood when evaluating long-term site productivity, future timber yields, plant diversity, stand dynamics, and …

Shifting Environmental Controls On Ch4 Fluxes In A Sub-Boreal Peatland, Thomas G. Pypker, P. A. Moore, John A. Hribljan, Rodney Chimner

Michigan Tech Publications

We monitored CO₂ and CH₄ fluxes using eddy covariance from 19 May to 27 September 2011 in a poor fen located in northern Michigan. The objectives of this paper are to: (1) quantify the flux of CH₄ from a sub-boreal peatland, and (2) determine which abiotic and biotic factors were the most correlated to the flux of CH₄ over the measurement period. Net daily CH₄ fluxes increased from 70 mg CH₄ m⁻² d⁻¹ to 220 mg CH₄ m⁻² d⁻¹ from mid May to mid July. After July, CH_{4 …}

Vulnerability Of High Latitude Soil Organic Carbon In North America To Disturbance, Guido Grosse, Jennifer Harden, Merritt Turetsky, David A. Mcguire, Philip Camill, Charles Tarnocai, Steve Frolking, Edward A.G. Schuur, Torre Jorgenson, Sergei Marchenko, Vladimir Romanovsky, Kimberly P. Wickland, Nancy H. F. French, Mark Waldrop, Laura Bourgeau-Chavez, Robert G. Striegl

Michigan Tech Research Institute Publications

This synthesis addresses the vulnerability of the North American high-latitude soil organic carbon (SOC) pool to climate change. Disturbances caused by climate warming in arctic, subarctic, and boreal environments can result in significant redistribution of C among major reservoirs with potential global impacts. We divide the current northern high-latitude SOC pools into (1) near-surface soils where SOC is affected by seasonal freeze-thaw processes and changes in moisture status, and (2) deeper permafrost and peatland strata down to several tens of meters depth where SOC is usually not affected by short-term changes. We address key factors (permafrost, vegetation, hydrology, paleoenvironmental history) …