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Item Ecosystem engineering at the streambed: how net-spinning caddisflies influence substrate flow dynamics(Montana State University - Bozeman, College of Letters & Science, 2020) MacDonald, Michael Joseph; Chairperson, Graduate Committee: Lindsey Albertson; Lindsey K. Albertson and Geoffrey C. Poole were co-authors of the article, 'Ecosystem engineering at the streambed: how net-spinning caddisflies influence substrate flow dynamics' submitted to the journal 'Ecohydrology' which is contained within this thesis.The streambed is an ecotone between surface waters and underlying hyporheic systems. Identifying the controls on advective flow through this ecotone is critical to understanding the movement of energy and matter in streams. Hydropsychids (net-spinning caddisflies) are aquatic macroinvertebrate ecosystem engineers that influence streambed cohesion, yet evidence of direct influence on hydrologic processes is lacking. Utilizing a novel downward flow permeameter, we demonstrate how net-spinning caddisfly colonization of the streambed interstitia at moderate but common densities (2,000 m^-2) can reduce the vertical hydraulic conductivity (KV) by up to 55% in coarse sand and gravels (median diameter = 12.91 mm). Sediment columns incubated in artificial stream water occupied by caddisflies showed greater reductions in KV relative to those without caddisflies. Additionally, organic matter content within sediment columns showed that occupation by caddisflies resulted in nearly two-fold increases in organic matter AFDM. Our research shows that the ubiquitous and numerous net-spinning caddisflies are likely to modulate the exchange of channel and hyporheic water by constructing nets in open pore spaces, increasing flow resistance, and decreasing flow velocities, as well as stimulating organic matter deposition with potential consequences for biofilm growth. These results suggest that caddisfly induced reductions to flow may influence transfer processes occurring at the streambed ecotone, altering biogeochemical processes in streams.Item Biofilm-induced carbonate precipitation at the pore-scale(Montana State University - Bozeman, College of Engineering, 2015) Connolly, James Martin; Chairperson, Graduate Committee: Robin Gerlach; Robin Gerlach was a co-author of the article, 'Microbially induced carbonate precipitation in the subsurface: fundamental reaction and transport processes' in the book 'Handbook of Porous Media, 3rd Ed.' which is contained within this thesis.; Megan Kaufman, Adam Rothman, Rashmi Gupta, George Redden, Martin Schuster, Frederick Colwell and Robin Gerlach were co-authors of the article, 'Construction of two ureolytic model organisms for the study of microbially induced calcium carbonate precipitation' in the journal 'Journal of microbiological methods' which is contained within this thesis.; Benjamin Jackson, Adam P. Rothman, Isaac Klapper and Robin Gerlach were co-authors of the article, 'Estimation of a biofilm-specific reaction rate: kinetics of bacterial urea hydrolysis in a biofilm' submitted to the journal 'NPJ biofilms and microbiomes' which is contained within this thesis.; Johannes Hommel and Robin Gerlach were co-authors of the article, 'Reactive transport and permeability reduction in a synthetic 2D porous medium with biofilm-induced carbonate precipitation' which is contained within this thesis.There are many methods available to decrease permeability in the subsurface but one that has been the subject of much research over the last decade is microbially-induced carbonate precipitation (MICP). In this process, microbial activity is promoted that increases pore water alkalinity. When calcium or other divalent cations are supplied to the system, solid carbonate minerals can form which occupy pore space and can decrease permeability. Permeability reduction can also come from microbial biofilms forming in the pore space. The goal of the work presented in this dissertation is to understand how pore space is affected, both physically and chemically, by biofilms and the precipitates that they can form. Fundamental research presented here is intended to inform ongoing application-based research and development. Previously it has been a challenge to image MICP at high resolution without the use of destructive techniques. To overcome that obstacle, a fluorescently-tagged bacterium capable of urea hydrolysis-driven MICP was constructed. Biofilms were grown in two-dimensional microscale porous media reactors and allowed to precipitate calcium carbonate under varied conditions. These reactors were imaged noninvasively using confocal microscopy so that both biofilms and carbonate minerals could be resolved at micrometer resolution. Image analysis was utilized to quantify how much pore space was occupied by the biofilm and minerals in order to estimate porosity reduction. Finally, pore-scale reactive transport modeling was utilized in order to estimate local concentrations within the reactors. The results show that the extent to which the porosity and permeability of the porous medium was decreased depended on when the calcium was added to the system. Also, periods of low flow were found to decrease porosity and permeability to a greater extent. This result adds to the evidence that a pulsed flow injection strategy may be most effective for permeability reduction via MICP in the subsurface. Additionally, reactive transport modeling predicts a heterogeneous mineral saturation environment at the pore-scale which highlights the challenge of predicting precipitation behavior in Darcy-scale reactive transport models.Item Water relations in highly calcareous very gravelly soils(Montana State University - Bozeman, College of Agriculture, 1978) McLean, Daniel LyleItem Irrigation-related sediment deposition and suspended sediment effects on saturated hydraulic conductivity(Montana State University - Bozeman, College of Agriculture, 1995) Parwana, NoorjahanItem Selective permeation through modified vinylindene fluoride membranes(Montana State University - Bozeman, College of Engineering, 1975) Zavaleta, RonanthItem Use of soil parameters to assess crop yield potential in Gallatin Valley, Montana : a study of soil quality(Montana State University - Bozeman, College of Agriculture, 1999) Saleh, ArsilItem Effects of carboxin, an oxathiin systemic fungicide, on cell permeability and DNA dependent RNA synthesis(Montana State University - Bozeman, College of Agriculture, 1971) Shively, Owen DanielItem Hydraulic property modification of saline-sodic soils by addition of calcium chloride(Montana State University - Bozeman, College of Agriculture, 1993) Woodbury, Bryan LeeItem Water retention and flow characteristics of six calcarious soils of Montana(Montana State University - Bozeman, College of Agriculture, 1987) Browne, Michael FrankItem The separation of SOâ‚‚and Nâ‚‚ by permeation through modified vinylidene fluoride membranes(Montana State University - Bozeman, College of Engineering, 1973) Seibel, Dennis Robert