I am semi-retired and on a teaching only contract, but remain available for informal discussions with undergraduate and postgraduate students.

My present research interests concern the chemical, physical and biological properties of soil with particular focus on soil hydrophobicity (or water repellency) and the factors which influence its measurement, expression, abatement, destruction and recurrence. This phenomenon influences the delayed onset of water infiltration into affected soils reducing storage capacity and promoting surface run-off and/or evaporation. Recently atomic force microscopy (AFM) has been used to examine the distribution of surface mechanical properties on soil mineral particle surfaces and this has been used to infer the distribution and strength of adhesion of adsorbed organic material on particle specimens drawn from both hydrophilic and hydrophobic soils. It is hoped to extend the range of investigations to examine the extent to which micro-organisms (and their by-products) within soils influence hydrophobicity.

The heating of surface soils as a result of wild fire, or the use of fire as a land management tool, has a variety of interesting effects on soil chemistry leading to a redistribution of hydrophobicity (and changes in its persistence) within the soil column and a potential wide variety of outcomes dependent on subsequent weather conditions.

Recent publications

• Cheng S, Doerr SH, Bryant R, Wright CJ, (2010) Effects of Isopropanol/Ammonia Extraction on Soil Water Repellency as Determined by Atomic Force Microscopy Soil Sci. Soc. Am. J. 74:1541–1552.
• Cheng S, Bryant R, Doerr SH, Wright CJ and Williams PR Investigation of Surface Properties of Soil Particles and Model Materials with Contrasting Hydrophobicity Using Atomic Force Microscopy. Environ. Sci Technol. 43 (17), 6500–6506 2009.
• Cheng S, Bryant R, Doerr SH, Wright CJ and Williams PR Application of atomic force microscopy to the study of natural and model soil particles. Journal of Microscopy 231, 3:384-394 2008.
• Bryant R, Doerr SH, Hunt G, Conan S. 2007. Effects of soil compaction on soil surface water repellency Soil Use and Management DOI: 10.1111/j.1475-2743.2007.00088.x
• Bryant R, Doerr SH, Helbig M. 2005. The effect of oxygen deprivation on soil hydrophobicity during heating. Int. J. Wildland Fire 14: 457:474. DOI: 10.1071/WF05035 1049-8001/05/040449
• Doerr SH, Douglas P, Evans R, Morley CP, Mullinger N, Bryant R, Shakesby RA. 2005a. Effects of heating and post-heating equilibration times on soil water repellency. Austral. J. Soil Res. 43: 261:267. DOI: 10.1071/SR04092 0004-9573/05/030261
• Doerr SH, Dekker LW, Ritsema CJ, Shakesby RA and Bryant R, ‘Water repellency of soils: The influence of ambient relative humidity’ Soil Science Society American Journal, 66, 2002, 401:405.

Conference Contributions

2nd International Conference on Biohydrology, Bratislava, Slovakia: 2009

Bryant, R, Cheng, S, Doerr, SH, Wright, CJ, Bayer, JV, Williams, PR: Nano-scale investigation of soil particles and model material surfaces with biofilms and contrasting hydrophobicity using atomic force microscopy (AFM)

Bouyoucos Conference 2007 on the origin of water repellency in soils, Florida: 29/04/07 - 03/05/07

Shuying: S. Cheng, J.V. Bayer, R. Bryant, S.H. Doerr, C. Wright, AFM study on physico-chemical features of soil organic matter on natural soil particles

Julia: Julia V. Bayer, R. Bryant, Shuying Cheng, Stefan H. Doerr, "Soil pH and soil particle fluorescence"

Biohydrology 2006 Prague: 19/09/06 - 22/09/06

Shuying: Cheng S, Bryant R, Wright C, Doerr SH, "Investigation of natural organic coatings affecting soil particle wettability using Atomic Force Microscopy"

Julia: Bayer J, Cheng S, Bryant R, Doerr SH, "Laser Scanning Confocal Microscopy (LSCM) study of surface properties of biological coated sand particles"

14th International conference Marrakech, Morocco: 14/05/06 - 19/05/06

Bryant R, Doerr SH and Morgenstern P (2006)
Laboratory simulations of the effect of various fire residence times on hydrophobicity within soil profiles. International Soil Conservation Organisation (ISCO 2006)

Geosciences Union, Vienna 2004

Doerr, S.H., Shakesby, R.A., Blake, W.H., Bryant, R., Vuurens, S.H., Stagnitti, F., Humphreys, G.S. & Wallbrink, P. (2004) Effects of different wildfire severities on soil wettability: evidence from field observations and controlled laboratory experiments on Australian eucalypt soils. Geophysical Research Abstracts, 6, #04713.

Bryant, R. Helbig M, and Doerr SH (2004) Heating effects on soil wettability under oxygen-deprived conditions: Results from a controlled laboratory study. Geophysical Research Abstracts, Vol. 6, #04724, SRef-ID: 1607-7962/gra/EGU04-A-04724