Judith Turk

Major Professor

My research is on the vesicular A (Av) horizon, which is a widespread feature of desert soils. The Av horizon forms in eolian material that accumulates at the surface of desert soils, most often beneath a desert pavement. Av horizons are characterized by the presence of discontinuous, vesicular pores; which form due to pressure from air bubbles that become trapped in the soil during rainstorms and expand as the soil dries. This discontinuous porosity, in addition to platy structure that forms in Av horizons, leads to low infiltration rates and shallow leaching depths in soils with Av horizons. I am interested in evaluating the conditions in which Av horizons form (e.g., texture of the parent material, position on the landscape), as well defining a quantitative relationship between Av horizon morphology and infiltration rates. Better understanding of the distribution of Av horizons, and their relationship to infiltration rate, will provide insight into the hydrologic behavior, and thereby the ecologic function, of desert soils.

Turk, J.K., and R.C. Graham. 2009. Soil carbon and nitrogen accumulation in a forested debris flow chronosequence, California. Soil Sci. Soc. Am. J. 73:1504-1509.
Turk, J.K., Goforth, B.R., Graham, R.C., Kendrick, K.J., 2008. Soil Morphology of a debris flow chronosequence in a coniferous forest, southern California, USA. Geoderma 146: 157-165.