Katerina M Dontsova

Interests

Teaching

Soil chemistry;Environmental chemistry; Integrated science;Soil science

Research

Soil science; Soil chemistry; Biogeochemistry; Geobiology; Interactions between physical, chemical, and biological processes in soils; Dissolution, precipitation, and sorption reactions in the soil; Mineral-organic interactions; Fate and transport of organic contaminants and nano-particles; Environmental quality

Courses

Scholarly Contributions

Books

• Dontsova, K. M., Taylor, S., Arthur, J., Becher, J., Brusseau, M. L., Hunt, E., Mark, N., Ringelberg, D., Simunek, J., & Walsh, M. (2022). Dissolution of NTO, DNAN, and Insensitive Munitions Formulations and Their Fates in Soils. Hanover, New Hampshire: Cold Regions Research and Engineering Laboratory.
• Dontsova, K. M., Balogh-Brunstad, Z., & Le Roux, G. (2020). Biogeochemical Cycles: Ecological Drivers and Environmental Impact. Wiley.
• Dontsova, K. M., Taylor, S., Pesce-Rodriguez, R., Brusseau, M. L., Arthur, J., Mark, N., Walsh, M., Lever, J., & Simunek, J. (2014). Dissolution of NTO, DNAN, and Insensitive Munitions Formulations and Their Fates in Soils. Hanover, NH: Cold Regions Research and Engineering Laboratory.
• Jenkins, T. F., Pennington, J. C., Ampleman, G., Thiboutot, S., Walsh, M. R., Walsh, M. R., Diaz, E., Dontsova, K. M., Hewitt, A. D., Walsh, M. E., Walsh, M. E., Bigl, S. R., Taylor, S., Macmillan, D. K., Clausen, J. L., Lambert, D. J., Perron, N., Lapointe, M. C., Brochu, S., , Brassard, M., et al. (2007). Characterization and Fate of Gun and Rocket Propellant Residues on Testing and Training Ranges: Interim Report 1. Cold Regions Research and Engineering Laboratory (U.S.).
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  Abstract : The objectives of the research described in this report are to characterize the deposition and accumulation of propellant residues at the various types of firing points at military firing ranges, develop process descriptors to allow estimation of environmental transport rates of individual energetic chemicals from these residues, and collect lysimeter and groundwater monitoring well samples to experimentally assess off-site transport of residues. Estimates of residue deposition are presented for the firing of 60- and 81-mm mortars and 105-mm howitzers. Experimental results are provided for propellant residue accumulation at antitank rocket, mortar, artillery, and small arms ranges at several installations. Results from soil column experiments on the transport of nitroglycerin, nitroguanidine, and diphenylamine also are presented with resulting transport property estimates. Also, an experiment to assess the deposition of ammonium perchlorate from Mk58 rocket motors is described.

Chapters

• Dontsova, K. M., Balogh-Brunstad, Z., & Chorover, J. D. (2020). Plants as Drivers of Rock Weathering. In Biogeochemical Cycles: Ecological Drivers and Environmental Impact(pp 33-58). Wiley.
• Dontsova, K. M., Balogh-Brunstad, Z., & Le Roux, G. (2020). Ecological Drivers and Environmental Impacts of Biogeochemical Cycles: Challenges and Opportunities. In Biogeochemical Cycles: Ecological Drivers and Environmental Impact(pp 301-306). Wiley.
• Zaharescu, D. G., Reinhard, C. T., Lybrand, R. A., Dontsova, K. M., Chorover, J. D., & Burghelea, C. I. (2020). Biological Weathering in the Terrestrial System. In Biogeochemical Cycles: Ecological Drivers and Environmental Impact(pp 1-32). American Geophysical Union (AGU). doi:10.1002/9781119413332.CH1
• Zaharescu, D., Burghelea, C., Dontsova, K. M., Reinhard, C., Chorover, J. D., & Lybrand, R. (2020). Biological Weathering in the Terrestrial System: An Evolutionary Perspective. In Biogeochemical Cycles: Ecological Drivers and Environmental Impact(pp 3-32). Wiley.
• Volkmann, T. H., Sengupta, A., Pangle, L., Dontsova, K. M., Troch, P. A., Meira, A., Neilson, J., Hunt, E., Chorover, J. D., Zeng, X., Van Haren, J. L., Barron-Gafford, G. A., Bugaj, A., Abramson, N., Sibayan, M., & Huxman, T. E. (2018). Controlled experiments of hillslope coevolution at the Biosphere 2 Landscape Evolution Observatory: Toward prediction of coupled hydrological, biogeochemical, and ecological change. In Hydrology of Artificial and Controlled Experiments. Rijeka, Croatia: InTech.
• Dontsova, K. M., & Taylor, S. (2017). High Explosives: Their Dissolution and Fate in Soils. In Energetic Materials: From Cradle to Grave. Springer. doi:10.1007/978-3-319-59208-4
• Sengupta, A., Pangle, L., Volkmann, T., Dontsova, K. M., Troch, P. A., Meira, A. A., Neilson, J. W., Hunt, E., Chorover, J. D., Zeng, X., Van Haren, J. L., Barron-Gafford, G. A., Bugaj, A., Abramson, N., Sibayan, M., & Huxman, T. E. (2017). Advancing understanding of hydrological and biogeochemical interactions in evolving landscapes through controlled experimentation and monitoring at the Landscape Evolution Observatory. In Terrestrial Ecosystem Research Infrastructures: Challenges, New Developments and Perspectives(pp 83-118). CRC Press.
• Taylor, S., Becher, J., Beal, S., Ringelberg, D., Spanggord, R., & Dontsova, K. M. (2017). Photo-transformation of explosives and their constituents. In Proceedings of the May 2017 JANNAF conference, Kansas City, MO. Joint Army Navy NASA Air Force (JANNAF) Interagency Propulsion Committee.
• Taylor, S., Dontsova, K. M., & Walsh, M. (2017). Insensitive Munitions Formulations: Their Dissolution and Fate in Soils. In Energetic Materials: From Cradle to Grave. Springer.
• Taylor, S., Halasz, A., Dontsova, K. M., Hawari, J., Thiboutot, S., & Ampleman, G. (2015). Munitions Related Contamination: Source Characterization, Fate, and Transport. In Technical Reference Document AVT-197 / RTG-063.. NATO Science and Technology Organization (STO).
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  Chapter in NATO handbook

Journals/Publications

• Cubello, F., Polyakov, V., Meding, S. M., Kadoya, W., Beal, S., & Dontsova, K. M. (2024). Movement of TNT and RDX from composition B detonation residues in solution and sediment during runoff.. Chemosphere, 350, 141023. doi:10.1016/j.chemosphere.2023.141023
• Polyakov, V., Kadoya, W., Beal, S., Morehead, H., Hunt, E., Cubello, F., Meding, S. M., & Dontsova, K. M. (2023). Transport of insensitive munitions constituents, NTO, DNAN, RDX, and HMX in runoff and sediment under simulated rainfall.. Science of The Total Environment, 866, 161434. doi:https://doi.org/10.1016/j.scitotenv.2023.161434
• Pugliese, G., Ingrisch, J., Meredith, L. K., Pfannerstill, E. Y., Thomas, K., Meeran, K., Byron, J., Purser, G., Gil-Loaiza, J., van Haren, J., Dontsova, K., Kreuzwieser, J., Ladd, N., Werner, C., & Williams, J. (2023). Effects of drought and recovery on soil volatile organic compound fluxes in an experimental rainforest. Nature Communications, 14(1), 5064.
• Amini-Tabrizi, R., Dontsova, K. M., Graf Grachet, N., & Tfaily, M. (2022). Elevated temperatures drive abiotic and biotic degradation of organic matter in a peat bog under oxic conditions. Science of The Total Environment, 804, 150045.
• Karls, B., Meding, S. M., Li, L., Polyakov, V., Kadoya, W., Beal, S., & Dontsova, K. M. (2023). A laboratory rill study of IMX-104 transport in overland flow. Chemosphere, 310, 136866. doi:https://doi.org/10.1016/j.chemosphere.2022.136866
• Avitia, M., Barrón-Sandoval, A., Hernández-Terán, A., Benítez, M., Barron-Gafford, G. A., Dontsova, K. M., Pavao-Zuckerman, M. A., & Escalante, A. E. (2021). Soil microbial composition and carbon mineralization are associated with vegetation type and temperature regime in mesocosms of a semiarid ecosystem. FEMS Microbiology Letters. doi:https://doi.org/10.1093/femsle/fnab012
• Ravi, S., Law, D. J., Caplan, J. S., Barron-Gafford, G. A., Dontsova, K. M., Espeleta, J. F., Villegas, J. C., Okin, G. S., Breshears, D. D., & Huxman, T. E. (2021). Biological invasions and climate change amplify each other’s effects on dryland degradation. Global Change Biology.
• Sengupta, A., Volkmann, T. H., Danczak, R. E., Stegen, J. C., Dontsova, K. M., Abramson, N., Bugaj, A. S., Volk, M. J., Matos, K. A., Meira-Neto, A. A., Barberan, A., Neilson, J. W., Maier, R. M., Chorover, J. D., Troch, P. A., & Meredith, L. (2021). Contrasting Community Assembly Forces Drive Microbial Structural and Potential Functional Responses to Precipitation in an Incipient Soil System.. Frontiers in Microbiology, 12(3414).
• Troya, D., Taylor, S., Qin, C., Hunt, E. A., Dontsova, K., & Abrell, L. (2021). Outdoor dissolution and photodegradation of insensitive munitions formulations IMX-101 and IMX-104: Photolytic transformation pathway and mechanism study.. Chemosphere, 280, 130672. doi:10.1016/j.chemosphere.2021.130672
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  New munition compounds have been developed to replace traditional explosives to prevent unintended detonations. However, insensitive munitions (IM) can leave large proportion of unexploded charge in the field, where it is subjected to photodegradation and dissolution in precipitation. The photolytic reactions occurring on the surfaces of IMX-101 and IMX-104 formulations and the subsequent fate of photolytic products in the environment were thoroughly investigated. The constituents of IMX-101 and IMX-104 formulations dissolve sequentially under rainfall in the order of aqueous solubility: 3-nitro-1,2,4-triazol-5-one (NTO) > nitroguanidine (NQ) > 2,4-dinitroanisole (DNAN) > 1,3,5-hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). A linear relationship between DNAN dissolution and rainwater volume was observed (r2: 0.86-0.99). It was estimated that it would take 16-228 years to completely dissolve these formulation particles under natural environmental conditions in Oracle, AZ. We used LC/MS/MS and GC/MS to examine the dissolution samples from IMX-101 and 104 particles exposed to rainfall and sunlight and found six DNAN photo-transformation products including 2-methoxy-5-nitrophenol, 4-methoxy-3-nitrophenol, 4-methoxy-3-nitroaniline, 2-methoxy-5-nitroaniline, 2,4-dinitrophenol, and methoxy-dinitrophenol, which are in good agreement with computational modeling results of bond strengths. The main DNAN photodegradation pathways are therefore proposed. Predicted eco-toxicity values suggested that the parent compound DNAN, methoxy-nitrophenols, methoxy-nitroanilines and the other two products (2,4-dinitrophenol and methoxy-dinitrophenol) would be harmful to fish and daphnid. Our study provides improved insight about the rain dissolution and photochemical behavior of IM formulations under natural conditions, which helps to form target-oriented strategies to mitigate explosive contamination in military training sites.
• Dusza, Y., Sanchez-Cañete, E. P., Galliard, J. L., Ferrière, R., Chollet, S., Massol, F., Hansart, A., Juarez, S., Dontsova, K., Haren, J. V., Troch, P., Pavao-Zuckerman, M. A., Hamerlynck, E., & Barron-Gafford, G. A. (2020). Biotic soil-plant interaction processes explain most of hysteric soil CO efflux response to temperature in cross-factorial mesocosm experiment. Scientific reports, 10(1), 905.
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  Ecosystem carbon flux partitioning is strongly influenced by poorly constrained soil CO efflux (F). Simple model applications (Arrhenius and Q) do not account for observed diel hysteresis between F and soil temperature. How this hysteresis emerges and how it will respond to variation in vegetation or soil moisture remains unknown. We used an ecosystem-level experimental system to independently control potential abiotic and biotic drivers of the F-T hysteresis. We hypothesized a principally biological cause for the hysteresis. Alternatively, F hysteresis is primarily driven by thermal convection through the soil profile. We conducted experiments under normal, fluctuating diurnal soil temperatures and under conditions where we held soil temperature near constant. We found (i) significant and nearly equal amplitudes of hysteresis regardless of soil temperature regime, and (ii) the amplitude of hysteresis was most closely tied to baseline rates of F, which were mostly driven by photosynthetic rates. Together, these findings suggest a more biologically-driven mechanism associated with photosynthate transport in yielding the observed patterns of soil CO efflux being out of sync with soil temperature. These findings should be considered on future partitioning models of ecosystem respiration.
• Becher, J. B., Beal, S. A., Taylor, S., Dontsova, K., & Wilcox, D. E. (2019). Photo-transformation of aqueous nitroguanidine and 3-nitro-1,2,4-triazol-5-one: Emerging munitions compounds. Chemosphere, 228, 418-426.
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  Two major components of insensitive munition formulations, nitroguanidine (NQ) and 3-nitro-1,2,4-triazol-5-one (NTO), are highly water soluble and therefore likely to photo-transform while in solution in the environment. The ecotoxicities of NQ and NTO solutions are known to increase with UV exposure, but a detailed accounting of aqueous degradation rates, products, and pathways under different exposure wavelengths is currently lacking. Here, we irradiated aqueous solutions of NQ and NTO over a 32-h period at three ultraviolet wavelengths (254 nm, 300 nm, and 350 nm) and analyzed their degradation rates and transformation products. NQ was completely degraded by 30 min at 254 nm and by 4 h at 300 nm, but it was only 10% degraded after 32 h at 350 nm. Mass recoveries of NQ and its transformation products were ≥80% for all three wavelengths, and consisted of large amounts of guanidine, nitrate, and nitrite, and smaller amounts of cyanamide, cyanoguanidine, urea, and ammonium. NTO degradation was greatest at 300 nm with 3% remaining after 32 h, followed by 254 nm (7% remaining) and 350 nm (20% remaining). Mass recoveries of NTO and its transformation products were high for the first 8 h but decreased to 22-48% by 32 h, with the major aqueous products identified as ammonium, nitrate, nitrite, and a urazole intermediate. Environmental half-lives of NQ and NTO in pure water were estimated as 4 and 6 days, respectively. We propose photo-degradation pathways for NQ and NTO supported by observed and quantified degradation products and changes in solution pH.
• Dusza, Y., Sanchez-Canete, E. P., Le Galliard, J., Ferriere, R. H., Chollet, S., Massol, F., Hansart, A., Juarez, S., Dontsova, K. M., Van Haren, J. L., Troch, P. A., Pavao-Zuckerman, M. A., Hamerlynck, E., & Barron-Gafford, G. A. (2019). Biotic soil-plant interaction processes explain most of hysteric soil CO2 efflux response to temperature in cross-factorial mesocosm experiment.. Scientific Reports.
• Sendupta, A., Stegen, J., Meira Neto, A. A., Wang, Y., Neilson, J. W., Tatarin, T., Hunt, E., Dontsova, K. M., Chorover, J. D., Troch, P. A., & Maier, R. M. (2019). Assessing Microbial Community Patterns During Incipient Soil Formation From Basalt. Journal of Geophysical Research: Biogeosciences, 124, 941–958. doi:10.1029/2017jg004315
• Zaharescu, D., Burghelea, C., Dontsova, K. M., Presler, J., Hunt, E., Domanik, K., Amistadi, M. K., Sandhaus, S., Munoz, E. N., Gaddis, E. E., Galey, M., Vaquera-Ibarra, M. O., Palacios-Menendez, M. A., Castrejón-Martinez, R., Roldán-Nicolau, E. C., Li, K., Maier, R. M., Reinhard, C. T., & Chorover, J. D. (2019). From rock to life. A mass balance analysis of oxidative biological weathering and biosignature formation. Scientific Reports, 9, 15006. doi:10.1038/s41598-019-51274-x
• Arthur, J., Mark, N., Taylor, S., Simunek, J., Brusseau, M. L., & Dontsova, K. M. (2018). Dissolution and transport of insensitive munitions formulations IMX-101 and IMX-104 in saturated soil columns. Science of the Total Environment, 624, 758-768.
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  Military training exercises can result in deposition of energetic residues on range soils, which ultimately can contaminate groundwater with munitions constituents. Column experiments followed by HYDRUS-1D modeling were conducted to evaluate dissolution and transport of energetic constituents from the new insensitive munitions (IM) formulations IMX-101, a mixture of 3-nitro-1,2,4-triazol-5-one (NTO), nitroguanidine (NQ), and 2, 4-dinitroanisole (DNAN), and IMX-104, a mixture of NTO, 1,3,5-hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and DNAN. NTO and DNAN are emerging contaminants associated with the development of insensitive munitions as replacements for traditional munitions. Flow interruption experiments were performed to investigate dissolution kinetics and sorption non-equilibrium between soil and solution phases. The results indicated that insensitive munitions compounds dissolved in order of their aqueous solubility, consistent with prior dissolution studies conducted in the absence of soil. Initial elution of the high concentration pulse of highly soluble NTO and NQ was followed by lower concentrations, while DNAN had generally lower and more constant concentrations in leachate. The sorption of NTO and NQ was low, while RDX, 1,3,5,7-octahydro-1,3,5,7-tetranitrotetrazocine (HMX, an impurity in technical grade RDX), and DNAN all exhibited appreciable sorption. DNAN transformation was observed, with formation of amino-reduction products 2-ANAN (2-amino-4-nitroanisole) and 4-ANAN (4-amino-2-nitroanisole). HYDRUS-1D model, incorporating one-dimensional advective-dispersive transport with particle dissolution and first-order solute transformation was used to simulate the measured breakthrough curves. Optimized dissolution parameters varied widely but were correlated between compounds in the same formulation. Determined adsorption coefficients generally agreed with values determined from batch and column studies conducted with pure NTO and DNAN, while mass-loss rate coefficients were in better agreement with ones from batch than column studies possibly due to suppression of microbial transformation during elution of high concentrations of explosives. Even in the low organic matter soils selected in this study DNAN experienced significant retardation and transformation, indicating potential for its natural attenuation.
• Burghelea, C., Zaharescu, D., Dontsova, K. M., Maier, R. M., Huxman, T. E., Amistadi, M. K., Hunt, E., & Chorover, J. D. (2018). Trace element mobilization during incipient bioweathering of four rock types. Geochimica et Cosmochimica Acta, 234, 98-114. doi:https://doi.org/10.1016/j.gca.2018.05.011
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  Lithogenic trace element (TE) patterns of distribution, fate, and behavior in soils are influenced by plants and microorganisms. Our controlled mesocosm experiments quantified how incipient weathering of mineral-bound TEs (Be, V, Sr, Ba, Cr, Co, Ni, Mo, Cu, Zn, As, Se, Ag, Cd, Sn, Sb, Tl, and Pb) varies across four porous mineral substrates (basalt, rhyolite, granite, and schist), in the presence of buffalo grass (Bouteloua dactyloides), associated bacteria, and arbuscular mycorrhizal fungi (AM), a common plant symbiont. Particular focus was given to the net transfer of elements between the solid and solution phases, including chemical denudation (loss of element from the rock to the solution), plant TE uptake, and total mobilization (sum of denudation loss and uptake into plant biomass). Results revealed differences in TE denudation among rocks, basalt having the highest loss and schist the lowest. TE leaching in solution was time-dependent and it was likely influenced by variations in pH and DOC that were rock- and treatment-specific. The element with the highest rock-normalized release to the solution and highest enrichment in plant biomass was Mo across all rocks. Plants decreased denudation loss compared to abiotic controls for a large number of TEs in all substrates due to plant uptake, but for some elements increase in weathering due to plant activity resulted in increased denudation. Differences in TE patterns of behavior could be related to their Goldschmidt groups. Plant uptake was controlled by TE availability in solution, as well as plant physiological requirements. Plants and associated microbiota significantly enhanced mobilization for the majority of TEs across all rocks. Mycorrhiza significantly increased above-ground plant biomass production in rhyolite and concentrations in plant tissues for a high number of TEs in basalt. TE uptake into biomass was positively correlated with percent mycorrhizal infection, particularly in basalt and rhyolite. Mycorrhizal fungi also influenced TE denudation, rock-water fractionation, and total mobilization according to the rock type. Mycorrhizal activity was associated with a significant decrease in pH and increase in DOC fluxes in schist, supporting the idea that fungi enhance production of root exudates especially in substrates that are difficult to weather. Our results highlight the importance of incipient weathering at the plant-rock interface for patterns of TE cycling. They also indicate the importance of mycorrhiza in mineral dissolution, TE denudation, plant element uptake, and biomass growth.
• Arthur, J., Mark, N., Taylor, S., Simunek, J., Brusseau, M. L., & Dontsova, K. M. (2017). Batch soil adsorption and column transport studies of 2, 4-dinitroanisole (DNAN) in soils. Journal of Contaminant Hydrology, 199, 14-23.
• Mark, N., Authur, J., Dontsova, K. M., Brusseau, M. L., Taylor, S., & Simunek, J. (2017). Column transport studies of 3-nitro-1,2,4-triazol-5-one (NTO) in soils. Chemosphere, 171, 427-434.
• Ruiz, J., Pelletier, J. D., Zeng, X., Breshears, D. D., Huxman, T. E., DeLong, S., Saleska, S. R., Chorover, J. D., Troch, P. A., Barron-Gafford, G. A., Dontsova, K. M., & Van Haren, J. L. (2017). CO2 diffusion into pore spaces limits weathering rate of an experimental basalt landscape. Geology, 45(3), 203-206. doi:10.1130/G38569.1
• Zaharescu􀀃, G. D., Burghelea, C., Dontsova, K. M., Chorover, J. D., Maier, R. M., Huxman, T. E., & Hunt, E. (2017). Ecosystem Composition Controls the Fate of Rare Earth Elements during Incipient Soil Genesis. Nature Scientific Reports, 7, 43208. doi:10.1038/srep43208
• Pohlmann, M., Dontsova, K. M., Root, R., Ruiz, J., Troch, P. A., & Chorover, J. D. (2016). Pore water chemistry reveals gradients in mineral transformation across a model basaltic hillslope. Geochemistry, Geophysics, Geosystems, 17(6), 2054–2069.
• Sengupta, A., Wang, Y., Meira, A. A., Matos, K., Dontsova, K. M., Root, R., Neilson, J. W., Chorover, J. D., Maier, R. M., & Troch, P. A. (2016). Soil Lysimeter Excavation for Coupled Hydrological, Geochemical, and Microbiological Investigations. JoVE, e54536. doi:10.3791/54536
• Burghelea, C., Zaharescu, G. D., Dontsova, K. M., Maier, R. M., Huxman, T., & Chorover, J. D. (2015). Mineral nutrient mobilization by plants from rock: Influence of rock type and arbuscular mycorrhiza. Biogeochemistry, 124(1-3), 187-203. doi:10.1007/s10533-015-0092-5
• Mark, N., Arthur, J., Dontsova, K. M., Brusseau, M. L., & Taylor, S. (2016). Adsorption and Attenuation Behavior of 3-nitro-1,2,4-triazol-5-one (NTO) for Eleven Soils. Chemosphere, 144, 1249–1255. doi:10.1016/j.chemosphere.2015.09.101
• Pangle, L., DeLong, S., Abramson, N., Adams, J., Barron-Gafford, G. A., Breshears, D. D., Brooks, P. D., Chorover, J. D., Dietrich, W. E., Dontsova, K. M., Durcik, M., Espeleta, J., Ferre, P. A., Ferriere, R. H., Henderson, W., Hunt, E., Huxman, T. E., Millar, D., Murphy, B., , Niu, Y., et al. (2015). The Landscape Evolution Observatory: A large-scale controllable infrastructure to study coupled Earth-surface processes. Geomorphology.
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• Taylor, S., Dontsova, K. M., Walsh, M., & Walsh, M. (2015). Outdoor Dissolution of Detonation Residues of Three Insensitive Munitions Formulations. Chemosphere, 134, 250-256. doi:http://dx.doi.org/10.1016/j.chemosphere.2015.04.041
• Dontsova, K. M., Zaharescu, G. D., Henderson, W., Verghese, S., Perdrial, N., Hunt, E., & Chorover, J. D. (2014). Impact of organic carbon on weathering and chemical denudation of granular basalt. Geochimica et Cosmochimica Acta, 139, 508-526.
• Niu, Y., Pasetto, D., Scudeler, C., Paniconi, C., Putti, M., Troch, P. A., DeLong, S., Dontsova, K. M., Pangle, L., Breshears, D. D., Chorover, J. D., Huxman, T. E., Pelletier, J. D., Saleska, S. R., & Zeng, X. (2014). Incipient subsurface heterogeneity and its effect on overland flow generation -- insight from a modeling study of the first experiment at the Biosphere 2 Landscape Evolution Observatory. Hydrol. Earth Syst. Sci., 18, 1873-1883.
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• Taylor, S., Park, E., Bullion, K., & Dontsova, K. (2015). Dissolution of three insensitive munitions formulations. Chemosphere, 119, 342-8.
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  The US military fires live munitions during training. To save soldiers lives both during training and war, the military is developing insensitive munitions (IM) that minimize unintentional detonations. Some of the compounds in the IM formulation are, however, very soluble in water, raising environmental concerns about their fate and transport. We measured the dissolution of three of these IM formulations, IMX101, IMX104 and PAX21 using laboratory drip tests and studied the accompanying changes in particle structure using micro computed tomography. Our laboratory drip tests mimic conditions on training ranges, where spatially isolated particles of explosives scattered by partial detonations are dissolved by rainfall. We found that the constituents of these IM formulations dissolve sequentially and in the order predicted by their aqueous solubility. The order of magnitude differences in solubility among their constituents produce water solutions whose compositions and concentrations vary with time. For IMX101 and IMX104, that contain 3-nitro-1,2,4-triazol-5-one (NTO), the solutions also vary in pH. The good mass balances measured for the drip tests indicate that the formulations are not being photo-or bio-transformed under laboratory conditions.
• Taylor, S., Ringelberg, D. B., Dontsova, K., Daghlian, C. P., Walsh, M. E., & Walsh, M. R. (2013). Insights into the dissolution and the three-dimensional structure of insensitive munitions formulations. Chemosphere, 93(9), 1782-1788.
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  PMID: 23916749;Abstract: Two compounds, 2,4-dinitroanisole (DNAN) and 3-nitro-1,2,4-triazol-5-one (NTO) are the main ingredients in a suite of explosive formulations that are being, or soon will be, fielded at military training ranges. We aim to understand the dissolution characteristics of DNAN and NTO and three insensitive muntions (IM) formulations that contain them. This information is needed to accurately predict the environmental fate of IM constituents, some of which may be toxic to people and the environment. We used Raman spectroscopy to identify the different constituents in the IM formulations and micro computed tomography to image their three-dimensional structure. These are the first three-dimensional images of detonated explosive particles. For multi-component explosives the solubility of the individual constituents and the fraction of each constituent wetted by water controls the dissolution. We found that the order of magnitude differences in solubility amongst the constituents of these IM formulations quickly produced hole-riddled particles when these were exposed to water. Micro-computed tomography showed that particles resulting from field detonations were fractured, producing conduits by which water could access the interior of the particle. We think that micro-computed tomography can also be used to determine the initial composition of IM particles and to track how their compositions change as the particles dissolve. This information is critical to quantifying dissolution and developing physically based dissolution models. © 2013.
• Andrew, D. R., Fitak, R. R., Munguia-Vega, A., Racolta, A., Martinson, V. G., & Dontsova, K. (2012). Abiotic factors shape microbial diversity in Sonoran desert soils. Applied and Environmental Microbiology, 78(21), 7527-7537.
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  PMID: 22885757;PMCID: PMC3485727;Abstract: High-throughput, culture-independent surveys of bacterial and archaeal communities in soil have illuminated the importance of both edaphic and biotic influences on microbial diversity, yet few studies compare the relative importance of these factors. Here, we employ multiplexed pyrosequencing of the 16S rRNA gene to examine soil- and cactus-associated rhizosphere microbial communities of the Sonoran Desert and the artificial desert biome of the Biosphere2 research facility. The results of our replicate sampling approach show that microbial communities are shaped primarily by soil characteristics associated with geographic locations, while rhizosphere associations are secondary factors. We found little difference between rhizosphere communities of the ecologically similar saguaro (Carnegiea gigantea) and cardón (Pachycereus pringlei) cacti. Both rhizosphere and soil communities were dominated by the disproportionately abundant Crenarchaeota class Thermoprotei, which comprised 18.7% of 183,320 total pyrosequencing reads from a comparatively small number (1,337 or 3.7%) of the 36,162 total operational taxonomic units (OTUs). OTUs common to both soil and rhizosphere samples comprised the bulk of raw sequence reads, suggesting that the shared community of soil and rhizosphere microbes constitute common and abundant taxa, particularly in the bacterial phyla Proteobacteria, Actinobacteria, Planctomycetes, Firmicutes, Bacteroidetes, Chloroflexi, and Acidobacteria. The vast majority of OTUs, however, were rare and unique to either soil or rhizosphere communities and differed among locations dozens of kilometers apart. Several soil properties, particularly soil pH and carbon content, were significantly correlated with community diversity measurements. Our results highlight the importance of culture-independent approaches in surveying microbial communities of extreme environments. © 2012, American Society for Microbiology.
• Jardine, K., Barron-Gafford, G. A., Norman, J. P., Abrell, L., Monson, R. K., Meyers, K. T., Pavao-Zuckerman, M., Dontsova, K. M., Kleist, E., Werner, C., & Huxman, T. E. (2012). Green leaf volatiles and oxygenated metabolite emission bursts from mesquite branches following light-dark transitions. Photosynthesis Research, 113(1-3), 321-333.
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  Green leaf volatiles (GLVs) are a diverse group of fatty acid-derived compounds emitted by all plants and are involved in a wide variety of developmental and stress-related biological functions. Recently, GLV emission bursts from leaves were reported following light-dark transitions and hypothesized to be related to the stress response while acetaldehyde bursts were hypothesized to be due to the 'pyruvate overflow' mechanism. In this study, branch emissions of GLVs and a group of oxygenated metabolites (acetaldehyde, ethanol, acetic acid, and acetone) derived from the pyruvate dehydrogenase (PDH) bypass pathway were quantified from mesquite plants following light-dark transitions using a coupled GC-MS, PTR-MS, and photosynthesis system. Within the first minute after darkening following a light period, large emission bursts of both C-5 and C-6 GLVs dominated by (Z)-3-hexen-1-yl acetate together with the PDH bypass metabolites are reported for the first time. We found that branches exposed to CO2-free air lacked significant GLV and PDH bypass bursts while O-2-free atmospheres eliminated the GLV burst but stimulated the PDH bypass burst. A positive relationship was observed between photosynthetic activity prior to darkening and the magnitude of the GLV and PDH bursts. Photosynthesis under (CO2)-C-13 resulted in bursts with extensive labeling of acetaldehyde, ethanol, and the acetate but not the C-6-alcohol moiety of (Z)-3-hexen-1-yl acetate. Our observations are consistent with (1) the "pyruvate overflow" mechanism with a fast turnover time (< 1 h) as part of the PDH bypass pathway, which may contribute to the acetyl-CoA used for the acetate moiety of (Z)-3-hexen-1-yl acetate, and (2) a pool of fatty acids with a slow turnover time (> 3 h) responsible for the C-6 alcohol moiety of (Z)-3-hexen-1-yl acetate via the 13-lipoxygenase pathway. We conclude that our non-invasive method may provide a new valuable in vivo tool for studies of acetyl-CoA and fatty acid metabolism in plants at a variety of spatial scales.
• Brantley, S. L., Megonigal, J. P., Scatena, F. N., Balogh-Brunstad, Z., Barnes, R. T., Bruns, M. A., Cappellen, P. V., Dontsova, K. M., Hartnett, H. E., Hartshorn, A. S., Heimsath, A., Herndon, E., Jin, L., Keller, C. K., Leake, J. R., Mcdowell, W. H., Meinzer, F. C., Mozdzer, T. J., Petsch, S., , Pett-Ridge, J., et al. (2011). Twelve testable hypotheses on the geobiology of weathering. Geobiology, 9(2), 140-165.
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  PMID: 21231992;Abstract: Critical Zone (CZ) research investigates the chemical, physical, and biological processes that modulate the Earth's surface. Here, we advance 12 hypotheses that must be tested to improve our understanding of the CZ: (1) Solar-to-chemical conversion of energy by plants regulates flows of carbon, water, and nutrients through plant-microbe soil networks, thereby controlling the location and extent of biological weathering. (2) Biological stoichiometry drives changes in mineral stoichiometry and distribution through weathering. (3) On landscapes experiencing little erosion, biology drives weathering during initial succession, whereas weathering drives biology over the long term.(4) In eroding landscapes, weathering-front advance at depth is coupled to surface denudation via biotic processes.(5) Biology shapes the topography of the Critical Zone.(6) The impact of climate forcing on denudation rates in natural systems can be predicted from models incorporating biogeochemical reaction rates and geomorphological transport laws.(7) Rising global temperatures will increase carbon losses from the Critical Zone.(8) Rising atmospheric PCO2 will increase rates and extents of mineral weathering in soils.(9) Riverine solute fluxes will respond to changes in climate primarily due to changes in water fluxes and secondarily through changes in biologically mediated weathering.(10) Land use change will impact Critical Zone processes and exports more than climate change. (11) In many severely altered settings, restoration of hydrological processes is possible in decades or less, whereas restoration of biodiversity and biogeochemical processes requires longer timescales.(12) Biogeochemical properties impart thresholds or tipping points beyond which rapid and irreversible losses of ecosystem health, function, and services can occur. © 2011 Blackwell Publishing Ltd.
• Deng, B., Medina, V., Reed, C., Bednar, A., Griggs, C., Dontsova, K. M., & Nestler, C. C. (2011). Uptake of cesium (Cs+) by building materials in aqueous batch systems. Journal of Environmental Engineering, 137(11), 990-995.
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  Abstract: Cesium-137 (C137) is a radioactive source that could be utilized in the construction of a radioactive dispersal device (RDD). The objective of this study was to examine the uptake of Cs+ by common structural materials in the presence of water by using batch experiments with nonradioactive cesium chloride (CsCl133) as a surrogate for the radionuclide. Uptake kinetics and adsorption isotherms of Cs+ were measured on a diverse set of building materials, as were the effects of pH on the sorption processes. The results showed that wood materials, metal filings, and organic building materials and supplies did not sorb significant amounts of Cs+, but red brick, concrete block, drop ceiling panels, and clay materials retained Cs+ strongly. Adsorption kinetics were fast, and sorption isotherms could be characterized as linear. The solution pH did not have a significant effect on Cs+ sorption. © 2011 American Society of Civil Engineers.
• Chappell, M. A., George, A. J., Dontsova, K. M., Porter, B. E., Price, C. L., Zhou, P., Morikawa, E., Kennedy, A. J., & Steevens, J. A. (2009). Surfactive stabilization of multi-walled carbon nanotube dispersions with dissolved humic substances. Environmental Pollution, 157(4), 1081-1087.
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  PMID: 19000646;Abstract: Soil humic substances (HS) stabilize carbon nanotube (CNT) dispersions, a mechanism we hypothesized arose from the surfactive nature of HS. Experiments dispersing multi-walled CNT in solutions of dissolved Aldrich humic acid (HA) or water-extractable Catlin soil HS demonstrated enhanced stability at 150 and 300 mg L-1 added Aldrich HA and Catlin HS, respectively, corresponding with decreased CNT mean particle diameter (MPD) and polydispersivity (PD) of 250 nm and 0.3 for Aldrich HA and 450 nm and 0.35 for Catlin HS. Analogous trends in MPD and PD were observed with addition of the surfactants Brij 35, Triton X-405, and SDS, corresponding to surfactant sorption maximum. NEXAFS characterization showed that Aldrich HA contained highly surfactive domains while Catlin soil possessed a mostly carbohydrate-based structure. This work demonstrates that the chemical structure of humic materials in natural waters is directly linked to their surfactive ability to disperse CNT released into the environment.
• Dontsova, K. M., Hayes, C., Pennington, J. C., & Porter, B. (2009). Sorption of high explosives to water-dispersible clay: Influence of organic carbon, aluminosilicate clay, and extractable iron. Journal of Environmental Quality, 38(4), 1458-1465.
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  PMID: 19465721;Abstract: Explosives in soils can present environmental problems for military installations. Fine, mobile particles represent the most reactive fraction of the soil and, therefore, are expected to adsorb explosives and potentially facilitate their transport. The objective of this study was to determine the relative significance of phyllosilicate clay, organic matter, and two forms of extractable iron in adsorption of 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) by the colloidal water-dispersible clay (WDC) fraction of the soil. The WDC fraction of two mineral and one organic soil was separated and then treated to remove organic carbon (OC) and several forms of iron (Feo, oxalate extractable, and Fed, dithionite-citrate extractable). Adsorption coefficients were determined for whole soils, untreated, and treated WDC. For mineral soils, adsorption of TNT and RDX on the WDC was greater than on the whole soil. The presence of OC increased explosives sorption by WDC. When OC was removed, iron interfered with TNT sorption. In the presence of OC, removal of Feo decreased RDX adsorption and increased TNT adsorption indicating different adsorption mechanisms. Organic carbon was a more significant indicator of explosives adsorption by WDC than clays or iron oxides and hydroxides. Therefore, OC is the most likely medium for facilitated transport of TNT and RDX. Copyright © 2009 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.
• Dontsova, K. M., Pennington, J. C., Hayes, C., Simunek, J., & Williford, C. W. (2009). Dissolution and transport of 2,4-DNT and 2,6-DNT from M1 propellant in soil. Chemosphere, 77(4), 597-603.
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  PMID: 19729186;Abstract: Live-fire training exercises can result in particulate propellant contamination on military training ranges and can potentially contaminate ground water. This study was conducted to evaluate dissolution of the 2,4-dinitrotoluene (2,4-DNT) and 2,6-dinitrotoluene (2,6-DNT) from the propellant formulation, M1 (87.6% nitrocellulose, 7.3% 2,4-DNT, 0.57% 2,6-DNT, 1.06% diphenylamine, 3.48% dibutyl phthalate) and their subsequent transport in soil. Batch dissolution studies were followed by saturated column transport experiments. Neat, dissolved 2,4-DNT, and M1 in solid and dissolved forms were used as influent to columns filled with Plymouth loamy sand (mesic, coated Typic Quartzipsamments) from Camp Edwards, MA. Dissolution rates and other fate and transport parameters were determined using the HYDRUS-1D code. M1 dissolution was limited by DNT diffusion from the interior of the pellet, resulting in an exponential decrease in dissolution rate with time. The HYDRUS-1D model accurately described release and transport of 2,4- and 2,6-DNT from M1 propellant. Dissolution rates for M1 in the stirred reactor and column studies were similar, indicating that batch dissolution rates are potentially useful to represent field conditions.
• Dontsova, K. M., Steefel, C. I., Desilets, S., Thompson, A., & Chorover, J. D. (2009). Solid phase evolution in the Biosphere 2 hillslope experiment as predicted by modeling of hydrologic and geochemical fluxes. Hydrology and Earth System Sciences, 13(12), 2273-2286.
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  Abstract: A reactive transport geochemical modeling study was conducted to help predict the mineral transformations occurring over a ten year time-scale that are expected to impact soil hydraulic properties in the Biosphere 2 (B2) synthetic hillslope experiment. The modeling sought to predict the rate and extent of weathering of a granular basalt (selected for hillslope construction) as a function of climatic drivers, and to assess the feedback effects of such weathering processes on the hydraulic properties of the hillslope. Flow vectors were imported from HYDRUS into a reactive transport code, CrunchFlow2007, which was then used to model mineral weathering coupled to reactive solute transport. Associated particle size evolution was translated into changes in saturated hydraulic conductivity using Rosetta software. We found that flow characteristics, including velocity and saturation, strongly influenced the predicted extent of incongruent mineral weathering and neo-phase precipitation on the hillslope. Results were also highly sensitive to specific surface areas of the soil media, consistent with surface reaction controls on dissolution. Effects of fluid flow on weathering resulted in significant differences in the prediction of soil particle size distributions, which should feedback to alter hillslope hydraulic conductivities.
• Kennedy, A. J., Hull, M. S., Steevens, J. A., Dontsova, K. M., Chappell, M. A., Gunter, J. C., & Weiss Jr., C. A. (2008). Factors influencing the partitioning and toxicity of nanotubes in the aquatic environment. Environmental Toxicology and Chemistry, 27(9), 1932-1941.
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  PMID: 19086318;Abstract: Carbon nanotubes (NTs) may be among the most useful engineered nanomaterials for structural applications but could be difficult to study in ecotoxicological evaluations using existing tools relative to nanomaterials with a lower aspect ratio. Whereas the hydrophobicity and van der Waals interactions of NTs may suggest aggregation and sedimentation in aquatic systems, consideration regarding how engineered surface modifications influence their environmental fate and toxicology is needed. Surface modifications (e.g., functional groups and coatings) are intended to create conditions to make NTs dispersible in aqueous suspension, as required for some applications. In the present study, column stability and settling experiments indicated that raw, multiwalled NTs (MWNTs) settled more rapidly than carbon black and activated carbon particles, suggesting sediment as the ultimate repository. The presence of functional groups, however, slowed the settling of MWNTs (increasing order of stability: hydroxyl > carboxyl > raw), especially in combination with natural organic matter (NOM). Stabilized MWNTs in high concentrations of NOM provided relevance for water transport and toxicity studies. Aqueous exposures to raw MWNTs decreased Ceriodaphnia dubia viability, but such effects were not observed during exposure to functionalized MWNTs (>80 mg/L). Sediment exposures of the amphipods Leptocheirus plumulosus and Hyalella azteca to different sizes of sediment-borne carbon particles at high concentration indicated mortality increased as particle size decreased, although raw MWNTs induced lower mortality (median lethal concentration [LC50], 50 to >264 g/kg) than carbon black (LC50, 18-40 g/kg) and activated carbon (LC50, 12-29 g/kg). Our findings stress that it may be inappropriate to classify all NTs into one category in terms of their environmental regulation. © 2008 SETAC Printed in the USA.
• Dontsova, K. M., Yost, S. L., Šimunek, J., Pennington, J. C., & Williford, C. W. (2006). Dissolution and transport of TNT, RDX, and composition B in saturated soil columns. Journal of Environmental Quality, 35(6), 2043-2054.
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  PMID: 17071873;Abstract: Low-order detonations and blow-in-place procedures on military training ranges can result in residual solid explosive formulations to serve as distributed point sources for ground water contamination. This study was conducted to determine if distribution coefficients from batch studies and transport parameters of pure compounds in solution adequately describe explosive transport where compounds are present as solid particles in formulations. Saturated column transport experiments were conducted with 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and the explosive formulation, Composition B (Comp B) (59.5 ± 2.0% RDX, 39.5 ± 2.3% TNT, and 1% wax) in solid and dissolved forms. The two soils used were Plymouth loamy sand (mesic, coated Typic Quartzipsamments) from Camp Edwards, MA and Adler silt loam (coarse-silty, mixed, superactive, thermic Fluvaquentic Eutrudepts) from Vicksburg, MS. Interrupted flow experiments were used to determine if explosives were at equilibrium distribution between soil and solution phases. The HYDRUS-ID code was used to determine fate and transport parameters. Results indicated that sorption of high explosives was rate limited. The behavior of dissolved Comp B was similar to the behavior of pure TNT and RDX. Behavior of solid Comp B was controlled by dissolution that depended on physical properties of the Comp B sample. Adsorption coefficients determined by HYDRUS-ID were different from those determined in batch tests for the same soils. Use of parameters specific to formulations will improve fate and transport predictions. © ASA, CSSA, SSSA.
• Dontsova, K. M., & Bigham, J. M. (2005). Anionic polysaccharide sorption by clay minerals. Soil Science Society of America Journal, 69(4), 1026-1035.
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  Abstract: An influence of clay mineral composition on C turnover in surface soils is widely assumed but poorly documented. The objective of this study was to evaluate the effect of various clay minerals on polysaccharide sorption under different environmental conditions, including pH, ionic strength, and cation type. Xanthan, an anionic polysaccharide produced by Xanthomonas campestris, was used to represent soil microbial exopolysaccharides. Highly significant effects (P > F < 0.0001) were observed for type of day mineral, pH, xanthan concentration, and electrolyte concentration. Sorption decreased with increase in pH from 3 to 8, consistent with an increase in the negative charge of both the clay surface and xanthan molecules. The presence of 10 mmol L -1 Ca(NO 3) 2 made sorption possible at pH values above the pKa of xanthan. Divalent cations (Sr 2+, Ca 2+, and Mg 2+) enhanced sorption to a greater degree than monovalent cations (K +, Na +, and Li +) at the same ionic strength, indicating that cations participated in the binding of xanthan to clay surfaces. Generally, sorption was smallest with kaolinite and greatest with a low-charge (0.62 e layer charge per unit cell) smectite where layer charge originated mostly in the tetrahedral positions. Average sorption was two times greater for smectite than for kaolinite, indicating that clay mineral composition influenced polysaccharide sorption; however, contributions may not be significant on a field scale. © Soil Science Society of America.
• Dontsova, K. M., Norton, L. D., & Johnston, C. T. (2005). Calcium and magnesium effects on ammonia adsorption by soil clays. Soil Science Society of America Journal, 69(4), 1225-1232.
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  Abstract: Anhydrous ammonia is a widely used N fertilizer and its interactions with soils and soil clays play an important role in its environmental fate. This study was conducted to determine the quantity and forms of ammonia adsorbed by clay-sized fractions of soils as a function of water content, exchangeable cation, and organic matter (OM). Fourier transform infrared spectroscopy was used to evaluate in situ the mechanisms of interaction of H 2O, NH 3, and NH 4+ with the clay-size fractions of a Blount loam (fine, illitic, mesic Aeric Epiaqualfs) and a Fayette silty clay loam (fine-silty, mixed, mesic, superactive Typic Hapludalfs). Due to NH 3 dissolution in adsorbed water more total N was sorbed at high (90%) than at low (2%) relative humidity (RH) despite decrease in the amount of NH 4+ sorbed. At high RH, the amount of NH 4+, NH 3, and total N increased by 12 to 23% on the Mg-exchanged compared with the Ca-exchanged soil clays. Of the two soil clays, the smectitic sample (Fayette) sorbed more of both N species than the illitic sample (Blount). Samples with OM removed adsorbed significantly more ammonia than untreated samples. The mechanism suggested for ammonia sorption by soil clays is a combination of protonation on water associated with metal cations, coordination to the exchangeable cations and dissolution in pore water. Soil clays can retain significant amounts of ammonium in excess of the cation exchange capacity (CEC) and out of competition for exchange sites. Dissolved NH 3 constituted the majority of N adsorbed by the sample at high RH, which is typical of field conditions. © Soil Science Society of America.
• Dontsova, K. M., Norton, L. D., Johnston, C. T., & Bigham, J. M. (2004). Influence of exchangeable cations on water adsorption by soil clays. Soil Science Society of America Journal, 68(4), 1218-1227.
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  Abstract: The interaction of water with the clay fractions ( F < 0.0001). The position of the H-O-H bending band (v2 mode) also increased with increasing ionic potential of the exchangeable cation indicating strengthening of water II bonds. In addition, it was observed that the position of this band decreased with increasing water content for the Mg-exchanged clays compared with an overall increase for the Ca-exchanged samples. X-ray diffraction patterns indicated an expansion of the phyllosilicate clay minerals as the water activity increased; howeveir, no differences were observed between the Ca- and Mg-exchanged samples. This study shows that the molecular properties of water on Ca- and Mg-exchanged soil clays are similar to that on specimen clays and provides new insight about the role of exchangeable cations in soils.
• Ventura, E., Norton, L. D., & Dontsova, K. (2003). SOIL DEGRADATION AS A RESULT OF WATER EROSION. Terra Latinoamericana, 21(2), 259-265.
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  Resumen es: The loss of topsoil is often thought of as the only ramification of soil erosion by water. However, there are other important degradational aspects of th...
• Dontsova, K. M., & Norton, L. D. (2002). Clay dispersion, infiltration, and erosion as influenced by exchangeable Ca and Mg. Soil Science, 167(3), 184-193.
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  Abstract: Soils of the US Corn Belt often experience surface sealing, low infiltration, and erosion under rainfall, all of which result in economic loss. This study seeks to establish if high Mg content in these soils can have an adverse effect on soil structure, clay dispersability, water intake rate, and erosion as a result of the greater hydration radius of Mg compared with Ca. The study modified the Ca/Mg ratio from four soils of the Midwestern United States that varied in organic matter (OM) content, clay content, and clay mineralogy. After that, flocculation behavior of the clay fraction as well as infiltration and erosion during simulated rainfall were examined. The Ca/Mg ratio had a significant effect on clay dispersion and surface sealing: for all soil clays, a negative linear relationship (R2 = 0.82 to 0.99) was observed between the Mg percentage in solution and optical transmittance of clay suspension as an indicator of clay flocculation. In rainfall experiments, well structured Mg-treated soils registered final infiltration rates approximately half those of Ca-treated soils (2.7 mm h-1 vs. 5.7 mm h-1 for Blount loam soil and 16.8 mm h-1 vs. 31.1 mm h-1 for Catlin silt loam soil). Total infiltration decreased significantly as well. However, the effect was not significant for two less stable soils. Magnesium saturation increased final and total soil losses significantly for Blount loam and Fayette silty clay loam. Results indicate that high Mg can cause increased surtace sealing and erosion in Midwestern soils.
• Norton, D., & Dontsova, K. M. (1998). Use of soil amendments to prevent soil surface sealing and control erosion. Advances in GeoEcology, 31, 581-587.
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  Surface sealing leads to low water infiltration rates producing runoff and erosion even in low intensity rainfall events. Structural instability and the low electrolyte concentration of rainwater leads to breakdown of aggregates and dispersion of colloids producing low steady state infiltration rates (I-s). It has been hypothesized that for some soils exchangeable Mg (ExMg) may behave similar to soils with Na causing dispersion and increased surface sealing. In order to study this effect, a rainfall simulator study was conducted to measure infiltration and erosion of five soils from the midwest USA. Small interrill plots (0.14 m(2)) were packed with the sieved soil and brought to saturation from below for 2 hours, and subjected to deionized rainfall at a rate of 64 mm/hr at 5% slope with -5 cm tension for one hour. Samples of infiltrating water and runoff were collected at 5-minute intervals. Soil loss was determined by measuring gravimetrically the sediment concentration in the runoff. Four replications for each soil were performed. In addition to the control, each soil was surface amended with anionic polyacrylamide (PAM) at 20 kg/ha, 5,000 kg/ha fluidized bed combustion bottom ash (FBCBA) and PAM plus FBCBA.
• Nearing, M. A., Norton, L. D., Bulgakov, D. A., Larionov, G. A., West, L. T., & Dontsova, K. M. (1997). Hydraulics and erosion in eroding rills. Water Resources Research, 33(4), 865-876.
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  Abstract: Rills often act as sediment sources and the dominant sediment and water transport mechanism for hillslopes. Six experiments were conducted on two soils and a uniform sand using three experimental methodologies. The results of this study challenge the assumption often used in hydrologic and erosion models that relationships derived for sheet flow or larger channel flow are applicable to actively eroding rills. Velocity did not vary with slope, and Reynolds number was not a consistent predictor of hydraulic friction. This result was due to interactions of slope gradient, flow rate, erosion, and the formation of rill roughness, bed structures, and head cuts. A relationship for rill flow velocities was proposed. Stream power was found to be a consistent and appropriate predictor for unit sediment load for the entire data set, while other hydraulic variables were not. The data for stream power and sediment load fit the form of a logistic curve (r2 = 0.93), which is promising relative to recently proposed erosion models which are based on probabilistic particle threshold theory.

Proceedings Publications

• Dontsova, K. M. (2015, December). Multilevel approach to mentoring in the Research Experiences for Undergraduates programs. In American Geophysical Union Annual Meeting.
• Dontsova, K. M. (2014, May). 5.0. Dissolution of NTO, DNAN and Insensitive Munitions Formulations and their Fates in Soils. In JANNAF Workshop proceedings - Fate, transport and effects of insensitive munitions: issues and recent data: Environmental Restoration Report.

Presentations

• Dontsova, K. M., & Bonine, K. E. (2023, December). ED54A-06: REU programs as a mechanism for developing STEM identity.. 2023 American Geophysical Union Fall Meeting. San Francisco, CA.
• Yazzie, R., Peterson, M., Karls, B., & Dontsova, K. M. (2023, September). The Landscape Evolution Observatory (LEO): Analysis of the organic and inorganic C and total N present within a simulated primary succession hillslope.. Fort Lewis College undergraduate seminar. Durango, CO.
• Cortes, L., & Dontsova, K. M. (2022, December 2022). Mineral Weathering, Soil Formation, and Carbon Sequestration as Influenced by Water Flow and Biota
  . American Geophysical Union Fall Meeting. Chicago, IL: American Geophysical Union.
• Dontsova, K. M., Brusseau, M. L., Meixner, T., Beal, S., Bigl, M., Kadoya, W., Polyakov, V., & Simunek, J. (2022, 19 October 2022). Integrative Approach to Quantifying Fate of Munitions Constituents on Training Ranges. In-Progress Review Meeting. virtual: SERDP.
• Guo, B., Cao, Z., Du, J., Wang, Y., Niu, G., Dontsova, K. M., Hitzelberger, M., Chen, L., Troch, P. A., & Chorover, J. D. (2022, December 2022). Reactive transport modeling of basalt weathering and early soil formation within a highly-controlled, sloping lysimeter.
  . American Geophysical Union Fall Meeting. Chicago, IL: American Geophysical Union.
• Zaharescu, D. G., Lybrand, R., Dontsova, K. M., & Chorover, J. D. (2022, July). Connecting weathering, entropy and the search for life. 2022 Goldschmidt Conference. Honolulu, HI.
• Brinkworth, C. S., Bonine, K. E., Lazrus, H., Wildcat, D., Whyte, K., Aponte, K. K., Dontsova, K. M., Morgan, K., Putsavage, K., Sparrow, E., Spellman, K., Morris, P., Spiehler, W., Coggins, J., & Schleuser, S. (2021, January 2021). Cocreating Hydrological Research between Earth Science Institutions and Indigenous Scientists and Communities: Success Stories and Lessons Learned. American Meteorological Society Annual Meeting. virtual: American Meteorological Society.
• Dontsova, K. M., Brusseau, M. L., Meixner, T., Beal, S., Bigl, M., Kadoya, W., Polyakov, V., & Simunek, J. (2021, 7 June 2021). Integrative Approach to Quantifying Fate of Munitions Constituents on Training Ranges. In-Progress Review Meeting. virtual: SERDP.
• Dontsova, K. M., Chorover, J. D., Van Haren, J. L., Juarez, S., & Pohlmann, M. (2021, November). Inorganic Carbon Accumulation in Soils during Early Development of Landscapes. Soil Science Society of America Annual Meeting. Salt Lake City, UT: Soil Science Society of America.
• Dontsova, K. M., Kadoya, W., Beal, S., Taylor, S., Brusseau, M. L., & Simunek, J. (2021, 16 August 2021). Phototransformation, Sorption, Transport, and Fate of Mixtures of NTO, DNAN, and Traditional Explosives as a Function of Climatic Conditions. In-Progress Review Meeting. virtual: SERDP.
• Lerma, A., Meding, M., Beers, R., Dontsova, K. M., & Meredith, L. (2021, December 2021). GC25H-0734 - Chemical Analysis of Soil Affected by Wildfire and Drought: Bighorn Fire and Biosphere 2 Rainforest Drought. American Geophysical Union Fall Meeting. New Orleans, LA: American Geophysical Union.
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  From June to July 2020, the Bighorn fire in the Tucson Catalina Mountains burned over 40,400 hectares, with4% of land experiencing high severity burns as described by the Burn Area Emergency Response Team(BAER 2020). In 2019, over 906,000 hectares of the Amazon Rainforest was burned during an unusually long dry season and deforestation. At Biosphere 2, the 1,900 m2 rainforest was used to create a controlled drought environment for the Water, Atmosphere and Life Dynamics (WALD) project which focused on analyzing all components of the effects of a 66-day drought. In collaboration with the WALD project and Arizona Geological Survey, this research project focuses on comparing how drought and fire affects soil chemistry across different biomes.For the drought portion of soil chemical analysis, focus was placed on the rhizosphere of the Arenga Pinnata (Sugar Palm) tree located in the lowlands of the Biosphere 2 rainforest. Analysis found that in comparison to a control area outside of the palm rhizosphere, soil salinity was higher and had larger variation throughout the drought. For pH, the palm rhizosphere experienced an overall lower pH than it’s control area counterpart; additionally, pH was found to rise during the most severe drought period in surface soils of the palm rhizosphere.When investigating the fire soils, comparing two vegetation sites across three burn severities, both vegetation sites had significantly different results across most analyses. pH of the Madrean Pine-Oak Woodlands sites decreased with fire severity while Ponderosa Pine Forest sites rose significantly. Electrical Conductivity of both sites experienced an increase with fire severity, but the Madrean site experienced a larger change than the Ponderosa site. Finally, major differences in the sites appeared most significantly in the carbon and nitrogen analysis. The Madrean site had a decline in carbon by weight as fire severity increased; however, Ponderosa site soil carbon reached it’s highest in high severity fire.
• Dontsova, K. M., Brusseau, M. L., Meixner, T., Beal, S., Bigl, M., Kadoya, W., Polyakov, V., & Simunek, J. (2020, 13 February 2020). Integrative Approach to Quantifying Fate of Munitions Constituents on Training Ranges. In-Progress Review Meeting. Washington, DC: SERDP.
• Dontsova, K. M., Taylor, S., Beal, S., Kadoya, W., Brusseau, M. L., & Simunek, J. (2020, May 2020). Phototransformation, Sorption, Transport, and Fate of Mixtures of NTO, DNAN, and Traditional Explosives as a Function of Climatic Conditions. In-Progress Review Meeting. virtual: SERDP.
• Chavarria, H. I., Lopez, J. M., Hunt, E., Meredith, L., Van Haren, J. L., & Dontsova, K. M. (2019, December 2019). EP53F-2209: Biosphere 2: The Changes of Soil Composition and Properties in Time in the Rainforest Biome.. American Geophysical Union Fall Meeting. San Francisco, CA: American Geophysical Union.
• Dontsova, K. M., & Bonine, K. E. (2019, December 2019). ED23E-16: The benefits of team-building and student empowerment for diverse REU cohorts.. American Geophysical Union Fall Meeting. San Francisco, CA: American Geophysical Union.
• Dontsova, K. M., Taylor, S., Brusseau, M. L., & Simunek, J. (2019, 1 May 2019). Phototransformation, Sorption, Transport, and Fate of Mixtures of NTO, DNAN, and Traditional Explosives as a Function of Climatic Conditions. In-Progress Review Meeting. Washington, DC: SERDP.
• Dontsova, K. M., Taylor, S., Qin, C., Hunt, E., Wang, Y., Brusseau, M. L., Simunek, J., & Troya, D. (2019, August). Fate of energetic compounds as influenced by environmental conditions.. 2019 Goldschmidt conference. Barcelona, Spain: European Association of Geochemistry and the Geochemical Society.
• Dontsova, K. M., Tfaily, M. M., Hunt, E., Chu, R. K., Toyoda, J., Chorover, J. D., & Troch, P. A. (2019, December 2019). B21H-2303: Spatial differences and temporal change in organic matter composition across artificial hillslope during incipient soil formation.. American Geophysical Union Fall Meeting. San Francisco, CA: American Geophysical Union.
• Lewis, J., Arthur, J., Brusseau, M. L., Simunek, J., Taylor, S., & Dontsova, K. M. (2019, December 2019). H21I-1861: Predicting Fate of Munitions Constituents in the Environment.. American Geophysical Union Fall Meeting. San Francisco, CA: American Geophysical Union.
• Dontsova, K. M. (2018, February). Fate and transport of energetics in the environment. Department of Soil, Water and Environmental science (SWES) Colloquium. Tucson, AZ: SWES.
• Dontsova, K. M., Brusseau, M. L., Taylor, S., Pesce-Rodriguez, R., & Simunek, J. (2018, February). Dissolution of NTO, DNAN and Insensitive Munitions Formulations and Their Fates in Soils. Project Number ER-2220. Final Project Summary. Washington, Dc: Strategic Environmental Research and Development Program.
• Dontsova, K. M., Juarez, S., Villasenor, E., Le Galliard, J., Chollet, S., Llavata, M., Massol, F., Hunt, E., Barre, P., Daval, D., Gelabert, A., Barron-Gafford, G. A., Van Haren, J. L., Troch, P. A., & Ferriere, R. H. (2019, January). Influence of Climate on Plant-Rock Interactions during Early Soil Development.. Science Society of America (SSSA) International Soils Meeting “Soils Across Latitudes”. San Diego, CA: Science Society of America.
• Dontsova, K. M., Taylor, S., Brusseau, M. L., & Simunek, J. (2018, February). Photo-transformation, Sorption, Transport, and Fate of Mixtures of NTO, DNAN, and Traditional Explosives as a Function of Climatic Conditions. Project Number ER-2727. In-Progress Review Meeting. Washington, DC: Strategic Environmental Research and Development Program.
• Dontsova, K. M., Taylor, S., Brusseau, M. L., Meixner, T., & Beal, S. (2018, September). Integrative Approach to Quantifying Fate of Munitions Constituents on Training Ranges (ER19-1074). Technical Review Board Meeting. Alexandria, VA: Strategic Environmental Research and Development Program.
• Qin, C., Dontsova, K. M., Hunt, E., & Taylor, S. (2019, January). Adsorption of Insensitive Munition to Water-Dispersible Clay: Impact of Organic Carbon, Aluminosilicate Clay, and Extractable Iron. Soil Science Society of America (SSSA) International Soils Meeting “Soils Across Latitudes”. San Diego, CA: Soil Science Society of America.
• Dontsova, K. M., Bonine, K. E., Batchelor, R. L., Brinkworth, C., Keller, J. M., Hogan, D., & Treloar, D. (2017, December 2017). Biosphere 2, a nexus of partner networks that improve student experiences and outcomes. American Geophysical Union Fall Meeting. San Francisco, CA: American Geophysical Union.
• Dontsova, K. M., Taylor, S., Arthur, J., Mark, N., Brusseau, M. L., Simunek, J., & Hunt, E. (2017, November). Fate and Transport of Insensitive Munitions Constituents. SERDP-ESTCP symposium. Washington, DC: The Strategic Environmental Research and Development Program (SERDP) and Environmental Security Technology Certification Program (ESTCP).
• Dontsova, K. M., Volk, M., Webb, C., Hunt, E., Tfaily, M. M., Van Haren, J. L., Sengupta, A., Chorover, J. D., Troch, P. A., & Ruiz, J. (2017, December 2017). Carbon and nitrogen accumulation and fluxes on Landscape Evolution Observatory (LEO) slopes. American Geophysical Union Fall Meeting. San Francisco, CA: American Geophysical Union.
• Taylor, S., Becher, J., Beal, S., Ringelberg, D., Spanggord, R., & Dontsova, K. M. (2017, May). Photo-transformation of explosives and their constituents. JANNAF conference. Kansas City, MO: JANNAF.
• Villasenor, E., Dontsova, K. M., Juarez, S., Le Galliard, J., Chollet, S., Llavata, M., Massol, F., Barré, P., Gelabert, A., Daval, D., Troch, P. A., Barron-Gafford, G. A., Van Haren, J. L., & Ferriere, R. H. (2017, December 2017). The effect of elevated CO2 and temperature on nutrient uptake by plants grown in basaltic soil. American Geophysical Union Fall Meeting. San Francisco, CA: American Geophysical Union.
• Volkmann, T. H., Sengupta, A., Pangle, L. A., Abramson, N., Barron-Gafford, G. A., Breshears, D. D., Bugaj, A., Chorover, J. D., Dontsova, K. M., Durcik, M., Ferre, P. A., Harman, C. J., Hunt, E. A., Kim, M., Maier, R. M., Matos, K. A., Alves Meira Neto, A., Meredith, L., Monson, R. K., , Niu, G., et al. (2017, December). Controlled Experiments of Hillslope Co-evolution at the Biosphere 2 Landscape Evolution Observatory: Toward Prediction of Coupled Hydrological, Biogeochemical, and Ecological change. AGU International Annual Meeting. New Orleans, LA: American Geophysical Union (AGU).
• Dontsova, K. M., Taylor, S., Brusseau, M. L., & Simunek, J. (2016, September). Phototransformation, Sorption, Transport, and Fate of Mixtures of NTO, DNAN, and Traditional Explosives as a Function of Climatic ConditionsProject Number (ER-2727). Brief to the Scientific Advisory Board. Washington, DC: Strategic Environmental Research and Development Program (SERDP).
• Juarez, S., Dontsova, K. M., Le Galliard, J., Chollet, S., Cros, A., Llavata, M., Barre, P., Massol, F., Gelabert, A., Daval, D., Troch, P. A., Barron-Gafford, G. A., Van Haren, J. L., & Ferriere, R. H. (2016, April 2016). Effect of elevated CO2 and temperature on abiotic and biologically-driven basalt weathering and C sequestration. 2016 EGU General Assembly. Vienna, Austria: European Geosciences Union.
• Juarez, S., Dontsova, K. M., Le Galliard, J., Chollet, S., Cros, A., Llavata, M., Barre, P., Massol, F., Gelabert, A., Daval, D., Troch, P. A., Barron-Gafford, G. A., Van Haren, J. L., & Ferriere, R. H. (2016, October 2016). Effect of CO2 and temperature on basalt weathering and microbial activity.. International Conference on Ecological Sciences sfecologie2016. Marseille, France.
• Dontsova, K. M., Huxman, T. E., Chorover, J. D., Maier, R. M., Zaharescu, G. D., & Burghelea, C. (2015, November). Grass and microbiota effect on lithogenic element mobilization during weathering of basalt, granite, rhyolite, and schist. Geological Society of America annual meeting. Baltimore, MD: Geological Society of America.
• Dontsova, K. M., Taylor, S., Brusseau, M. L., & Simunek, J. (2015, May). Dissolution of NTO, DNAN and Insensitive Munitions Formulations and Their Fates in Soils. ER-2220.. SERDP In-Progress Review Meeting. Arligton,􀀃 Virginia.􀀃: Strategic Environmental Research and Development Program (SERDP).
• Dontsova, K. M., Taylor, S., Halaz, A., Hawari, J., Thiboutot, S., & Ampleman, G. (2015, October). Fate and Transport of Munitions Constituents. AVT‐244 Specialists Meeting on "Munitions Related Contamination". Prague, Czech Republic: NATO.
• Dontsova, K. M., Zaharescu, G. D., Burghelea, C., Chorover, J. D., Maier, R. M., & Huxman, T. E. (2015, July). Nutrient mobilization during biological weathering. Frontiers in Experimental Ecosystem Science. Paris, France: CNRS, ENS.
• Dontsova, K. M., Taylor, S., Brusseau, M. L., & Simunek, J. (2014, May). Dissolution of NTO, DNAN and Insensitive Munitions Formulations and Their Fates in Soils. ER-2220.. SERDP In-Progress Review Meeting. Arlington, Virginia: Strategic Environmental Research and Development Program (SERDP).
• Ruiz, J., Barron-Gafford, G. A., Van Haren, J. L., Dontsova, K. M., Troch, P. A., & Chorover, J. D. (2014, December). Rapid CO2 consumption during incipient weathering of a granular basaltic hillslope in the Landscape Evolution Observatory, Biosphere 2.. American Geophysical Union’s Annual Fall Meeting.
• Zaharescu, D., Dontsova, K. M., Burghelea, C., Maier, R. M., Huxman, T. E., & Chorover, J. D. (2014, December). Cracking the Code of Soil Genesis. The Early Role of Rare Earth Elements. American Geophysical Union (AGU) Fall Meeting. San Francisco, CA.

Poster Presentations

• Dontsova, K. M., Cortes, L., Makke, G., Tfaily, M., Garcia, J., Sengupta, A., Arnold, A. E., Chorover, J. D., & Saleska, S. R. (2023, July). Effects of biocrust formation and moss colonization on biogeochemical properties of basaltic tephra.. Goldschmidt conference. Lyon, France.
• Dontsova, K. M., Karls, B., Cancès, B., Bauda, P., Cebron, A., Jaunat, J., & Meixner, T. (2023, June). Evaluating potential for ground and surface water contamination from new and traditional munitions. . International Symposium of Labex DRIIHM-2023 Inter-Disciplinary Research Facility on Human-Environment interactions – ANR-11-LABX-0010.. Strasbourg, France.
• Dontsova, K. M., Karls, B., Polyakov, V., Cubello, F., Taylor, S., Kadoya, W., Beal, S., Brusseau, M. L., & Meixner, T. (2023, November). Integrative Approach to Quantifying Fate of Munitions Constituents on Training Ranges (ER19-1074). Department of Defense's (DoD) Energy and Environment Innovation Symposium. Arlington, VA: Strategic Environmental Research and Development Program (SERDP).
• Dontsova, K. M., Taylor, S., Qin, C., Hunt, E., Brusseau, M. L., & Simunek, J. (2023, November). Photo-transformation, Sorption, Transport, and Fate of Mixtures of NTO, DNAN, and Traditional Explosives as a Function of Climatic Conditions (ER-2727). Department of Defense's (DoD) Energy and Environment Innovation Symposium. Arlington, Virginia: Strategic Environmental Research and Development Program (SERDP).
• Duncan, V., Bugaj, A., Cubello, F., Dontsova, K. M., Chorover, J. D., & Saleska, S. R. (2023, December). H21M-1527: Changes in Mineral Composition and Nutrient Availability in Early Succession Soils. . 2023 American Geophysical Union Fall Meeting. San Francisco, CA.
• Jianwen, D., Guo, B., Niu, G., Dontsova, K. M., Troch, P. A., & Chorover, J. D. (2023, December). H21M-1526: Quantifying the impact of CO2 transport and transient hydrological flow on basalt weathering at the Biosphere 2 Landscape Evolution Observatory.. 2023 American Geophysical Union Fall Meeting. San Francisco, CA.
• Makke, G., Bugaj, A., Dontsova, K. M., Chorover, J. D., Arnold, A. E., Saleska, S. R., & Tfaily, M. (2023, July). FTICR-Based Metabolomics Reveals the Dynamics of Soil Metabolic Complexity of Primary Succession at the Landscape Evolutionary Observatory at Biosphere 2, AZ, USA. Goldschmidt conference. Lyon, France.
• McNerney, K., Saleska, S. R., Ng, W., Van Haren, J. L., Leford, S., Nabours, R., Hardy, J., Peterson, M., Burks, J., Pytosh, A., Durcik, M., Dontsova, K. M., & Bugaj, A. (2023, December). EP53D-1761: Effects of Sunlight, Temperature and Moisture on Small CO2 Fluctuations of Bare Soil, Soil with Moss and Soil with a Biocrust on a Landscape Evolutionary Observatory.. 2023 American Geophysical Union Fall Meeting. San Francisco, CA.
• Reynoso, A., Peterson, M., Dontsova, K. M., Fehmi, J. S., Van Haren, J. L., & Rasmussen, C. (2023, October). Exploring the potential for enhanced weathering for carbon sequestration in Arizona agricultural systems.. Soil Science Society of America (SSSA) International Annual Meeting. St. Louis, MO.
• Cruz Campos, A. E., Launderville, E., Dontsova, K. M., & Rasmussen, C. (2022, December 2022). Basalt to the rescue: a study of carbon sequestration
  . American Geophysical Union Fall Meeting. Chicago, IL: American Geophysical Union.
• Dontsova, K. M., Karls, B., Polyakov, V., Cubello, F., Taylor, S., Kadoya, W., Beal, S., Brusseau, M. L., & Meixner, T. (2022, November). Integrative Approach to Quantifying Fate of Munitions Constituents on Training Ranges (ER19-1074). 2022 SERDP, ESTCP and OE-Innovation Symposium. Arlington, VA: Strategic Environmental Research and Development Program (SERDP).
• Kadoya, W., Beal, S., & Dontsova, K. M. (2022, November). Penetration depth of ultraviolet light into solid IMX-101 and IMX-104. ER19-1074.. 2022 SERDP, ESTCP and OE-Innovation Symposium. Arlington, VA: Strategic Environmental Research and Development Program (SERDP).
• Launderville, E., Dontsova, K. M., Cruz Campos, A. E., Rasmussen, C., & Fehmi, J. S. (2022, December 2022). Enhanced Weathering for Carbon Sequestration by Alfalfa in Basalt Corrected Arid Agricultural Soil. American Geophysical Union Fall Meeting. Chicago, IL: American Geophysical Union.
• Makke, G., Bugaj, A., Dontsova, K. M., Sengupta, A., Chorover, J. D., Arnold, A. E., Saleska, S. R., & Tfaily, M. (2022, December 2022). Changes in the Soil Metabolic Complexity Driven by Plant Succession at the Landscape Evolutionary Observatory at Biosphere 2
  . American Geophysical Union Fall Meeting. Chicago, IL: American Geophysical Union.
• Dontsova, K. M., Karls, B., Polyakov, V., Li, L., Taylor, S., Kadoya, W., Beal, S., Brusseau, M. L., & Meixner, T. (2021, November). Integrative Approach to Quantifying Fate of Munitions Constituents on Training Ranges (ER19-1074). 2021 SERDP & ESTCP Symposium. virtual: Strategic Environmental Research and Development Program (SERDP).
• Kadoya, W., Beal, S., & Dontsova, K. M. (2021, November). Phototransformationof 2,4-dinitroanisole (DNAN), 3-nitro-1,2,4-triazol-5-one (NTO), and nitroguanidine (NQ) in mixtures (ER19-1074). 2021 SERDP & ESTCP Symposium. virtual: Strategic Environmental Research and Development Program (SERDP).
• Araújo, J. B., Brusseau, M. L., Meixner, T., Simunek, J., & Dontsova, K. M. (2020, December). Influence of Environmental Factors on Fate and Transport of Insensitive Munitions (IM) Constituents (ER19-1074). 2020 SERDP & ESTCP Symposium. virtual: Strategic Environmental Research and Development Program (SERDP).
• Dontsova, K. M., Karls, B., Polyakov, V., Li, L., Taylor, S., Kadoya, W., Beal, S., Brusseau, M. L., & Meixner, T. (2020, December). Integrative Approach to Quantifying Fate of Munitions Constituents on Training Ranges (ER19-1074). 2020 SERDP & ESTCP Symposium. virtual: Strategic Environmental Research and Development Program (SERDP).
• Dontsova, K. M., Taylor, S., Qin, C., Hunt, E., Brusseau, M. L., & Simunek, J. (2020, December). Photo-transformation, Sorption, Transport, and Fate of Mixtures of NTO, DNAN, and Traditional Explosives as a Function of Climatic Conditions (ER-2727). 2020 SERDP & ESTCP Symposium. virtual: Strategic Environmental Research and Development Program (SERDP).
• Dontsova, K. M., Lewis, J., Arthur, J., Taylor, S., Beal, S., Simunek, J., Brusseau, M. L., Meixner, T., & Kadoya, W. (2019, December). Integrative Approach to Quantifying Fate of Munitions Constituents on Training Ranges.. 2019 SERDP & ESTCP Symposium. Washington, DC: Strategic Environmental Research and Development Program (SERDP).
• Dontsova, K. M., Taylor, S., Qin, C., Wang, Y., Hunt, E., & Brusseau, M. L. (2019, December). Photo-transformation, Sorption, Transport, and Fate of Mixtures of NTO, DNAN, and Traditional Explosives as a Function of Climatic Conditions.. 2019 SERDP & ESTCP Symposium. Washington, DC: Strategic Environmental Research and Development Program (SERDP).
• Kadoya, W., Beal, S., Dontsova, K. M., & Taylor, S. (2019, December). UV irradiation of NTO, NQ and DNAN solids: comparison of dry and moist conditions.. 2019 SERDP & ESTCP Symposium. Washington, DC: Strategic Environmental Research and Development Program (SERDP).
• Kadoya, W., Beal, S., Taylor, S., & Dontsova, K. M. (2019, December). Phototransformation of Insensitive Munitions Compounds (IMCs) in the Presence of Humic Acids.. 2019 SERDP & ESTCP Symposium. Washington, DC: Strategic Environmental Research and Development Program (SERDP).
• Bonine, K. E., & Dontsova, K. M. (2018, September). Pathways, research, & broader impacts converge at Biosphere 2: The value of context for an REU site. 2018 GEO REU PI Workshop. Boulder, CO: NSF REU.
• Dontsova, K. M., & Bonine, K. E. (2018, April). Biosphere 2 & Student Research for Environmental Solutions. The American Indian Science & Engineering Society (AISES) Region 3 conference. Tucson, AZ: AISES.
• Dontsova, K. M., Bonine, K. E., Batchelor, R., & Brinkworth, C. (2018, December). ED43G-1300 Immersive undergraduate research experiences: maximizing benefits for diverse students.. American Geophysical Union fall meeting. Washington, DC: American Geophysical Union.
• Dontsova, K. M., Qin, C., Hyatt, L., Hunt, E., Brusseau, M. L., Taylor, S., & Troya, D. (2018, November). Outdoor Photo-Transformation and Dissolution of the Insensitive Munitions Formulations IMX-101 and IMX-104. 2018 SERDP & ESTCP Symposium. Washington, DC: Strategic Environmental Research and Development Program (SERDP).
• Dontsova, K. M., Qin, C., Wang, Y., Hyatt, L., Hunt, E., Taylor, S., Brusseau, M. L., & Simunek, J. (2018, November). Soil interactions of legacy and insensitive munitions constituents. 2018 SERDP & ESTCP Symposium. Washington, DC: Strategic Environmental Research and Development Program (SERDP).
• Hitzelberger, M., Wang, Y., Dontsova, K. M., Hunt, E., Chorover, J. D., & Troch, P. A. (2018, August). Coupling Hydrologic Processes and Geochemical Weathering Patterns in a Fully Controlled Basaltic Soil Lysimeter. 2018 Undergraduate Research Opportunities Consortium (UROC) symposium. Tucson, AZ: UA Graduate college.
• Hitzelberger, M., Wang, Y., Dontsova, K. M., Hunt, E., Chorover, J. D., & Troch, P. A. (2018, December). ED13E-0792: Coupling Hydrologic Processes and Geochemical Weathering Patterns in a Fully Controlled Basaltic Soil Lysimeter. American Geophysical Union fall meeting. Washington, DC: American Geophysical Union.
• Hyatt, L., Qin, C., Hunt, E., Brusseau, M. L., & Dontsova, K. M. (2018, April). Analytical Methods for the Analysis of Photo-transformation Products of Insensitive Munitions. SWESx conference. Tucson AZ: SWES.
• Kadoya, W., Beal, S., Taylor, S., Dontsova, K. M., & Field, J. A. (2018, November). Phototransformation Kinetics and Products of Aqueous 2,4-Dinitroanisole (DNAN).. 2018 SERDP & ESTCP Symposium. Washington, DC: Strategic Environmental Research and Development Program (SERDP).
• Kim, M., Volkmann, T., Abramson, N., Bugaj, A., Hunt, E., Matos, K., Meira Neto, A., Sengupta, A., Wang, Y., Meredith, L., Dontsova, K. M., Harman, C., Chorover, J. D., & Troch, P. A. (2018, December). H13N-1958 Experimental observation of a hillslope-scale rank StorAge Selection function: Process controls on its functional form, time variability, and hysteresis.. American Geophysical Union fall meeting. Washington, DC: American Geophysical Union.
• Qin, C., Hyatt, L., Abrell, L. M., Troya, D., Hunt, E., Taylor, S., & Dontsova, K. M. (2018, August). Outdoor Photolysis and Dissolution of Insensitive Munition Formulation IMX-101 and IMX-104: Transformation Pathway and Mechanism Study. 256th American Chemical Society National Meeting & Exposition. Boston, MA: American Chemical Society.
• Sengupta, A., Barberan, A., Stegen, J., Volkmann, T., Dontsova, K. M., Neilson, J. W., Chorover, J. D., Maier, R. M., Troch, P. A., & Meredith, L. (2018, August). Structural and functional response of incipient basaltic microbial community to shifts in soil moisture regime. Goldschmidt. Boston, MA.
• Sengupta, A., Barberan, A., Stegen, J., Volkmann, T., Dontsova, K. M., Neilson, J. W., Chorover, J. D., Maier, R. M., Troch, P. A., & Meredith, L. (2019, January). Structural and Functional Response of Microbial Community in an Oligotrophic Basalt Soil System to Shifts in Rainfall Regimes. Soil Science Society of America (SSSA) International Soils Meeting “Soils Across Latitudes”. San Diego, CA: Soil Science Society of America.
• Wang, Y., Hyatt, L., Qin, C., Brusseau, M. L., & Dontsova, K. M. (2019, January). Saturated Column Transport Studies of Insensitive and Traditional Munitions in Soil. Soil Science Society of America (SSSA) International Soils Meeting “Soils Across Latitudes”. San Diego, CA: Soil Science Society of America.
• Zaharescu, G. D., Szeinbaum, N., Burghelea, C., Dontsova, K. M., Chorover, J. D., & Reinhard, C. (2018, August). Oxidative Biological Weathering and its Archean Origins. Goldschmidt. Boston, MA.
• Dontsova, K. M., Taylor, S., Arthur, J., Mark, N., Brusseau, M. L., Simunek, J., & Hunt, E. (2017, November). Release of Insensitive Munitions Constituents from Particular Formulations and Their Behavior in Soils. SERDP-ESTCP symposium. Washington, DC: The Strategic Environmental Research and Development Program (SERDP) and Environmental Security Technology Certification Program (ESTCP).
• Dontsova, K. M., Taylor, S., Brusseau, M. L., Simunek, J., & Hunt, E. (2017, November). Influence of Climate on Dissolution and Phototransformation of NTO and DNAN from Insensitive Munitions and Their Fate in Soils. SERDP-ESTCP symposium. Washington, DC: The Strategic Environmental Research and Development Program (SERDP) and Environmental Security Technology Certification Program (ESTCP).
• Howard, E., Van Haren, J. L., & Dontsova, K. M. (2017, December). Carbon uptake in granular basalt is mitigated by added organic carbon. American Geophysical Union fall meeting. New Orleans, LA: American Geophysical Union.
• Van Haren, J. L., Sanchez-Canete, E., Juarez, S., Howard, E., Dontsova, K. M., Le Galliard, J., Barron-Gafford, G. A., Volkmann, T., & Troch, P. A. (2017, December). Projected effects of vegetation and organic matter on soil carbon dynamics after rainfall in a model basalt landscape. American Geophysical Union fall meeting. New Orleans, LA: American Geophysical Union.
• Bonine, K. E., & Dontsova, K. M. (2016, September). Effective REU at Remote Site. GEO REU workshop. Boulder, CO: NSF.
• Dontsova, K. M., Juarez, S., Le Galliard, J., Chollet, S., Cros, A., Llavata, M., Barre, P., Massol, F., Gelabert, A., Daval, D., Troch, P. A., Barron-Gafford, G. A., Van Haren, J. L., & Ferriere, R. H. (2016, June 2016). Basalt Weathering under Controlled Conditions as Influenced by Biota, Temperature, and CO2. The 26th Goldschmidt Conference. Yokohama, Japan: The European Association for Geochemistry and Geochemical Society.
• Dontsova, K. M., Taylor, S., Pesce‐Rodriguez, R., Brusseau, M. L., Simunek, J., Arthur, J., & Mark, N. (2016, 6‐10 November). Dissolution of insensitive munition constituents and their fate and transport in soils.. SETAC North America 37th Annual Meeting/7th SETAC World Congress. Orlando, FL: Society of Environmental Toxicology and Chemistry.
• Hingley, R., Dontsova, K. M., Juarez, S., Hunt, E., Le Galliard, J., Chollet, S., Cros, A., Llavata, M., Barre, P., Massol, F., Gelabert, A., Daval, D., Troch, P. A., Barron-Gafford, G. A., Van Haren, J. L., & Ferriere, R. H. (2016, December 2016). Effects of Climate Change and Vegetation Type on Carbon and Nitrogen Accumulation during Incipient Soil Formation. American Geophysical Union Fall Meeting. San Francisco, CA: American Geophysical Union.
• Umanzor, M., Wang, Y., Dontsova, K. M., Chorover, J. D., & Troch, P. A. (2016, December 2016). A Centimeter‐Scale Investigation of Geochemical Hotspots in a Soil Lysimeter. American Geophysical Union Fall Meeting. San Francisco, CA: American Geophysical Union.
• Dontsova, K. M., Bonine, K. E., Pavao-Zuckerman, M., Paavo, B., Hogan, D., Oberg, E., & Gay, J. (2015, December). Multilevel approach to mentoring in the Research Experiences for Undergraduates programs. American Geophysical Union (AGU) Fall Meeting. San Francisco, CA: American Geophysical Union (AGU).
• Dontsova, K. M., Taylor, S., Arthur, J., Mark, N., Brusseau, M. L., & Simunek, J. (2015, July 2015). Dissolution of NTO, DNAN and Insensitive Munitions Formulations and Their Fates in Soils. Strategic Workshop on Research & Demonstration Needs for Management of Munitions Constituents. Washington, DC: Strategic Environmental Research and Development Program (SERDP).
• Juarez, S., Dontsova, K. M., Le Galliard, J., Chollet, S., Cros, A., Llavata, M., Barre, P., Massol, F., Gelabert, A., Daval, D., Troch, P. A., Barron-Gafford, G. A., Van Haren, J. L., & Ferriere, R. H. (2015, 20-24 Sep 2015). Abiotic and biologically-­‐driven basalt weathering and carbon sequestration under changing climate. 5th International Symposium on Soil Organic Matter. Göttingen (DE).
• Taylor, S., & Dontsova, K. M. (2015, July 2015). Dissolution of three Insensitive Munitions Formulations, IMX-101, IMX-104, and PAX-21. Strategic Workshop on Research & Demonstration Needs for Management of Munitions Constituents. Washington, DC: Strategic Environmental Research and Development Program (SERDP).
• Arthur, J., Mark, N., Dontsova, K. M., Brusseau, M. L., & Taylor, S. (2014, December). Batch Soil Adsorption Studies of 2,4-dinitroanisole (DNAN). American Geophysical Union (AGU) Fall Meeting. San Francisco, CA.
• Pavao-Zuckerman, M., & Dontsova, K. M. (2014, March). Biosphere 2 REU Program in Environmental and Earth Systems Research. GEO REU Workshop 2014. Boulder,􀀃 CO: NSF.
• Troch, P. A., Barron-Gafford, G. A., Dontsova, K. M., Fang, Y., Niu, Y., Pangle, L., Tuller, M., & Van Haren, J. L. (2014, December). Monitoring and Modeling Water, Energy and Carbon Fluxes at the Hillslope Scale in the Landscape Evolution Observatory. American Geophysical Union (AGU) Fall Meeting. San Francisco, CA.
• Wu, R., Niu, Y., Chorover, J. D., Dontsova, K. M., & Troch, P. A. (2014, December). Reactive Transport Modelling of Mineral Evolution in the Biosphere 2 Hillslope Experiment. American Geophysical Union (AGU) Fall Meeting. San Francisco, CA.
• Barron-Gafford, G. A., Minor, R. L., van Haren, J., Dontsova, K. M., & Troch, P. A. (2013, December). Precipitation pulse dynamics of carbon sequestration and efflux in highly weatherable soils. Annual Meeting of the American Geophysical Union. San Francisco, CA: American Geophysical Union.
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  Soils are the primary pool for terrestrial carbon on Earth, and loss of that carbon to the atmosphere or hydrosphere represents a significant efflux that can impact a host of other downstream processes. Soil respiration (Rsoil), the efflux of CO2 to the atmosphere, represents the major pathway by which carbon is lost from the soil system in more weathered soils. However, in newly formed soils, chemical weathering can significantly deplete soil CO2 concentrations. As vegetation colonizes these soils, multiple interacting and contradictory pathways evolve such that soil CO2 concentrations increase in response to plant inputs but are decreased through chemical reactions. Furthermore, abiotic drivers of soil temperature and moisture likely differentially affect these processes. Understanding the bio-geo-chemical drivers and feedbacks associated with soil CO2 production and efflux in the critical zone necessitates an integrated science approach, drawing on input from plant physiologists, bio- and geochemists, and hydrologists. Here, we created a series of 1-meter deep mesocosms filled with granular basalt that supported either a woody mesquite shrub, a bunchgrass, or was left as bare soil. Use of multiple plant functional types allowed us to explore the impacts of plant structure (primarily rooting profiles) on critical zone function in terms of water and carbon exchange surrounding precipitation pulse dynamics. Each mesocosm was outfitted with an array of soil moisture, temperature, water potential, and CO2 concentration sensors at the near-surface, 30, 55, and 80cm depths to quantify patterns of soil moisture and respiratory CO2 efflux in response to rainfall events of varying magnitude and intervening periods of drought. Five replicates of each were maintained under current ambient or projected (+4oC) air temperatures. In addition, we used minirhizotrons to quantify the response of roots to episodic rainfall and confirm differences among plant types and collected soils solution samples to quantify dissolved inorganic carbon (DIC), pH, and other solute concentrations.Importantly, we found Rsoil dynamics to be nearly in direct contrast to our classic understanding of patterns of soil CO2 efflux after rain events. Rsoil rates declined immediately upon wetting and gradually increased to pre-rain rates as the soils dried. Investigation into soil CO2 profile data showed that CO2 concentrations just below the surface declined significantly from near-ambient levels to near ~50ppm, which would directly impact rates of Rsoil. We detected differences among plant functional types in terms of rooting depth, water use, photosynthetic uptake, base rates of Rsoil, the time required to return to pre-rain rates of Rsoil, and the rates of soil weathering. Combining aboveground measurements of carbon uptake with these belowground estimates of carbon pools and efflux will allow us to make much more informed projections of carbon dynamics within highly weatherable soils across a range of global climate change projections and plant functional types.Experiment webpage: http://www.u.arizona.edu/~gregbg/Research__Biosphere_2_Mesocosm.htmlParent project webpage: http://leo.b2science.org/
• van Haren, J., Barron-Gafford, G. A., & Dontsova, K. M. (2013, December). CO2 sequestration through weathering of basalt tephra in the Landscape Evolution Observatory (LEO). Annual Meeting of the American Geophysical Union. San Francisco, CA: American Geophysical Union.
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  Weathering of primary silicates is one of the mechanisms involved in carbon removal from the atmosphere, affecting the carbon cycle at geologic timescales. Basalt is one of the most reactive rocks and thus a strong contributor to geologic weathering fluxes. The Landscape Evolution Observatory (LEO), an Earth science research facility at Biosphere 2, Tucson, AZ, consisting of three identical 350m2 and 1m deep slopes, allows conducting controlled experiments investigating the interactions between atmosphere, hydrosphere, lithosphere, and biosphere at an unprecedented scale. This study presents results of the initial experiments where granular basalt that serves as a soil medium in LEO was exposed to rainfall. Soil solution and drainage were collected and analyzed to determine changes in solution composition. Gas-phase CO2 concentrations in the soil were monitored using custom gas samplers and Vaisala CO2 probes and CO2 gas fluxes on the surface was determined using soil chambers. The goal of the study was to determine the impact of precipitation on incipient CO2 driven weathering reactions and inorganic C sequestration in the basalt and how these reactions were distributed along hillslope flow paths. Results indicate a very strong relationship between water inputs and soil CO2 concentrations and fluxes. Within hours of a rainfall event, the surface CO2flux increased three-fold, while soil CO2 concentrations were reduced from near atmospheric to

Others

• Dontsova, K. M. (2020, May). White Paper - Modeling Framework. Strategic Environmental Research and Development Program (SERDP) program office.
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  Invited white paper that details how experiments performed for the project ER19-1074 will inform modeling framework to describe fate and transport of energetic compounds in the environment.
• Dontsova, K. M., & Kadoya, W. (2020, July). White Paper - ER‐2727: Photo‐transformation, Sorption, Transport, and Fate of Mixtures of NTO, DNAN, and Traditional Explosives as a Function of Climatic Conditions. Strategic Environmental Research and Development Program (SERDP) program office.
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  Invited white paper that details how photolysis measurements performed under controlled conditions in the laboratory experiments can be extended to estimate phototransformation under natural sunlight conditions in different climates.
• Dontsova, K. M., Araújo, J., Beal, S., Bigl, M., Brusseau, M. L., Kadoya, W., Karls, B., Li, L., Meixner, T., Nearing, M., Polyakov, V., Taylor, S., & Simunek, J. (2021, January). ER19-1074 Integrative Approach to Quantifying Fate of Munitions Constituents on Training Ranges. Interim report.. Report.
• Dontsova, K. M., Field, J. A., & Johnson, M. (2016, June 2016). SERDP ESTCP Webinar # 34. Insensitive munitions. SERDP ESTCP webinar series. https://www.serdp-estcp.org/Tools-and-Training/Webinar-Series/06-02-2016
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  The Strategic Environmental Research and Development Program (SERDP) and the Environmental Security Technology Certification Program (ESTCP) have launched a webinar series to promote the transfer of innovative, cost-effective and sustainable solutions developed through projects funded by these programs. The webinar series targets Department of Defense and Department of Energy practitioners, the regulatory community and environmental researchers with the goal of providing cutting edge and practical information that is easily accessible at no cost.