My research focuses on examining the effects and distribution of soil properties such as pore-size distribution and soil architecture on soil-water flux. In addition, I am also generally interested in arid zone soils and particularly interested in the formation and mineralogy of soil inorganic carbon and the genesis and biogeochemical cycling of soils in desert mountains. Key research includes: (1) understanding the relationship between mineral dissolution, pedogenic carbonate, and hillslope hydrology; (2) effects of soil architecture on hydraulic properties; (3) relating lateral distributions of inorganic carbon, nitrate, and soluble salts to surface and near-surface properties; and (4) using process-based modeling to predict landscape-scale hydraulic properties from the distribution of inorganic carbon. Most recently, I, along with several colleagues and graduate students, have pioneered the use of MLT technology to scan the surface topography of soil aggregates and excavation walls to non-destructively measure soil properties such as bulk density, porosity, and roughness. Using this technology, soil architecture can be linked quantitatively to macropore flow and solute transport. This research will help to better elucidate soil-landscape response to past and future environmental conditions.
- Flipped courses, threshold concepts, discipline-based education research
- Pedology, soil-geomorphology, soil morphology, soil physics
Billings, S. A., Hirmas, D. R., Sullivan, P. L., Lehmeier, C. A., Bagchi, S. Min, K. Brecheisen, Z. Hauser, E. Stair, R. Flournoy, R. & Richter, D. d. (in press). Loss of deep roots limits biogenic agents of soil development that are only partially restored by decades of forest regeneration. Elementa: Science of the Anthropocene.
Hirmas, D. & Mandel, R. (2017). Soils of the Great Plains. In L. T. West, A. E. Hartemink, & M. J. Singer (Eds.), Soils of the USA. Dordrecht, Netherlands: Springer.
Hirmas, D. R., & Giménez, D. (2017). A geometric equation for representing morphological field information in horizons with compound structures. Soil Science Society of America Journal, 81, 863-867. DOI:10.2136/sssaj2016.12.0396
Hirmas, D. R., Giménez, D. Mome Filho, E. A., Patterson, M. Drager, K. Platt, B. F., & Eck, D. V. (2016). Quantifying soil structure and porosity using three-dimensional laser scanning. In . (Ed.), Digital Soil Morphometrics (pp. 19-35). Dordrecht, Netherlands: Springer.
Mohammed, A. K., Hirmas, D. R., Giménez, D. & Miller, J. R. (2016). A digital morphometric approach for quantifying ped shape. Soil Science Society of America Journal, 80, 1604-1618. DOI:10.2136/sssaj2016.06.0203
Drager, K. Hirmas, D. R., & Hasiotis, S. T. (2016). Effects of ant (Formica subsericea) bioturbation on physical and hydrological properties of a fine-textured soil. Soil Science Society of America Journal, 80, 364-375. DOI:10.2136/sssaj2015.08.0300
Drager, K. Hirmas, D. R., Hasiotis, S. T., & Bents, T. C. (2016). Effects of ant (Formica subsericea) nest development on physical and hydrological properties in a coarse-textured soil. Soil Science, 181, 166-174.
Katz, B. S., Stotler, R. L., Hirmas, D. R., Ludvigson, G. Smith, J. J., & Whittemore, D. O. (2016). Geochemical recharge estimation and the effects of a declining water table. Vadose Zone Journal, 15(10). DOI:10.2136/vzj2016.04.0031
Kim, D. Hirmas, D. R., McEwan, R. W., Mueller, T. G., Park, S. J., Samonil, P. Thompson, J. A., & Wendroth, O. (2016). Predicting the influence of multi-scale spatial autocorrelation on soil-landform modeling. Soil Science Society of America Journal, 80, 409-419.
Eck, D. Qin, M. Hirmas, D. Giménez, D. & Brunsell, N. (2016). Relating quantitative soil structure metrics to saturated hydraulic conductivity. Vadose Zone Journal, 15(1). DOI:10.2136/vzj2015.05.0083
Kraus, C. Hirmas, D. & Roberts, J. (2015). Compressive strength of blood stabilized earthen architecture. In C. Mileto, F. Vegas, L. García Soriano, & V. Christini (Eds.), Earthen Architecture: Past, Present and Future (pp. 217-220). London, UK: Taylor & Francis Group.
Klopfenstein, S. Hirmas, D. & Johnson, W. (2015). Relationships between soil organic carbon and precipitation along a climosequence in loess-derived soils of the central Great Plains, USA. Catena, 133, 25-34.
Rabenhorst, M. Schmehling, A. Thompson, J. Hirmas, D. Graham, R. & Rossi, A. (2015). Reliability of soil color standards. Soil Science Society of America Journal, 79, 193-199.
Halfen, A. F., White, T. Slocum, T. A., Hirmas, D. R., McDermott, D. Atchley, P. Johnson, W. C., Egbert, S. & Gilbreath, A. (2014). A new stereoscopic (3D) media database and teaching strategy for use in large-lecture introductory geoscience courses. Journal of Geoscience Education, 62, 515-531.
Hirmas, D. R., Slocum, T. A., Halfen, A. F., White, T. Zautner, E. Atchley, P. Liu, H. Johnson, W. C., Egbert, S. & McDermott, D. (2014). Effects of seating location and stereoscopic display on learning outcomes in an introductory physical geography class. Journal of Geoscience Education, 62, 126-137.
Kraus, C. Hirmas, D. & Roberts, J. (2013). Microbially indurated rammed earth: A long awaited next phase of earthen architecture. In C. Jarrett, K. Kim, & N. Senske (Eds.), The Visibility of Research, Proceedings of the 2013 Architectural Research Centers Consortium (pp. 58-65). Charlotte, NC: University of North Carolina Charlotte.
Hirmas, D. R. (2013). A simple method for removing artifacts from moist fine-textured soil faces. Soil Science Society of America Journal, 77, 591-593.
Hirmas, D. R., Giménez, D. Subroy, V. & Platt, B. F. (2013). Fractal distribution of mass from the millimeter- to decimeter-scale in two soils under native and restored tallgrass prairie. Geoderma, 207-208, 121-130.
Eck, D. V., Hirmas, D. R., & Giménez, D. (2013). Quantifying soil structure from field excavation walls using multistripe laser triangulation scanning. Soil Science Society of America Journal, 77, 1319-1328.
Hirmas, D. R., Platt, B. F., & Hasiotis, S. T. (2012). Determination of calcite and dolomite content in soils and paleosols by continuous coulometric titration. Soil Science Society of America Journal, 76, 1100-1106.
Platt, B. F., Hasiotis, S. T., & Hirmas, D. R. (2012). Empirical determination of physical controls on megafaunal footprint formation through neoichnological experiments with elephants. PALAIOS, 27(725-737).
Subroy, V. Giménez, D. Hirmas, D. R., & Takhistov, P. (2012). On determining soil aggregate bulk density by displacement in two immiscible liquids. Soil Science Society of America Journal, 76, 1212-1216.
Wysocki, D. A., Schoeneberger, P. J., Hirmas, D. R., & LaGarry, H. E. (2011). Geomorphology of Soil Landscapes. In P. M. Huang, Y. Li, & M. E. Sumner (Eds.), Handbook of Soil Sciences: Properties and Processes(2nd ed.) (pp. 29:1-29:26). Boca Raton, FL: CRC Press.
Hirmas, D. R., & Graham, R. C. (2011). Pedogenesis and soil-geomorphic relationships in an arid mountain range, Mojave Desert, CA. Soil Science Society of America Journal, 75, 192-206.
Hirmas, D. R., Graham, R. C., & Kendrick, K. J. (2011). Soil-geomorphic significance of land surface characteristics in an arid mountain range, Mojave Desert, USA. Catena, 87, 408-420.