My research interests are in arid zone soils, specifically, genesis and biogeochemical cycling of soils in desert mountains.  I am interested in quantitatively describing soil morphology, relating these variables to landscape processes, and applying numerical models to study pedological phenomena. This research will help to understand soil-landscape response to past and future environmental conditions. More information available here.

Pietrasiak, N., D.R. Hirmas. Comparison of hydrometer method settling times in particle size analysis for soils with high sand fractions. Soil Sci. (In Review)

Hirmas, D.R., C. Amrhein, and R.C. Graham. Spatial and process-based modeling of soil inorganic carbon storage in an arid piedmont. Geoderma. (In Press)

Rossi, A.M., D.R. Hirmas, R.C. Graham, and P.D. Sternberg. Bulk density determination by automated three-dimensional laser scanning. Soil. Sci. Soc. Am. J. 72:1591-1593

Graham, R.C., D.R. Hirmas, Y.A. Wood, and C. Amrhein. 2008. Large near-surface nitrate pools in soils capped by desert pavement in the Mojave Desert, California. Geology. 36:259-262.

Hirmas, D.R., and B.L. Allen. 2007. Degradation of pedogenic calcretes in West Texas. Soil Sci. Soc. Am. J. 71:1878-1888.

Hirmas, D.R., and S.A.C. Furquim. 2006. A simple modification of the clod method for determining bulk density of very gravelly soils. Comm. Soil Sci. Plant Anal. 37:899-906.

Hirmas, D.R., R.C. Graham, and C. Amrhein.  Pedogenesis and soil-geomorphology of the arid southern Fry Mountains, Mojave Desert.