ABSTRACT The purpose of this research is to explore the variability on the soil thermal conductivity -?- after a prescribe fire, and to assess the effects of the ashes on the heat transfer once it’s were incorporated into the soil matrix. Sampling plot was located in the Montgrí Massif (NE of Spain). A set of 42 soil samples between surface and 5 cm depth was collected before and after the fire. To characterize the soil chemical and physical variables were analyzed. To determine the variability on the soil λ a dry-out curve per scenario (before and after fire) was determined. SoilRho ? method based on ASTM D-5334-08 which was validated by LabFerrer was used. Soil thermal conductivity has shown changes in their values. Indeed, in all moisture scenarios the values of soil λ decreased after soil was burnt. The critical point in the relationshipθ(λ) for the soil after fire which always was stronger than soil before to be burnt. Soil with “white” ashes showed a high thermal conductivity. An X-Ray diffractometry analysis allowed to clarify and to verify these results. To sum up, we could say that thermal conductivity presents changes when the scenario changes, i.e. before and after to be burnt. On the other hand, the volume of ashes incorporated on the soil increased the differences between no burnt and burnt soil, showing even some improvements on the heat transfer when water content started to govern the process.
Cite this paper
C. Rubio, X. Ubeda and F. Ferrer, "Response of the Thermal Conductivity as a Function of Water Content of a Burnt Mediterranean Loam Soil," Open Journal of Soil Science, Vol. 2 No. 1, 2012, pp. 1-6. doi: 10.4236/ojss.2012.21001.
 L. F. DeBano, D. G. Neary and P. F. Ffolliott, “Fire’s Effects on Ecosystems,” JohnWiley & Sons, New York, 1999.
 L. F. DeBano, D. G. Neary and P. F. Ffolliott, “Chapter 2: Soil Physical Properties,” In: D. G. Neary, K. C. Ryan and L. F. DeBano, Eds., Wildland Fire in Ecosystems: Effects of Fire on Soil and Water, United States Department of Agriculture, Ogden, 2005, pp. 29-51.
 W. J. Massman, J. M. Frank and N. B. Reisch, “Long- Term Imapcts of Prescribed Burns on Soil Thermal Conductivity and Soil Heating at a Colorado Rocky Mountain Site: A Data/Model Fusion Study,” International Journal of Wildland Fire, Vol. 17, No. 1, 2008, pp. 131-146.
 E. L. Huffman, L. H. MacDonald and J. D. Stednick, “Strength and Persistence of Fire-Induced Soil Hydrophobicity under Ponderosa and Lodgepole Pine, Colorado Front Range,” Hydrological Processes, Vol. 15, No. 15, 2001, pp. 2877-2892. doi:/10.1002/hyp.379
 D. G. Neary, K. C. Ryan, L. F. DeBano, J. D. Landsberg and J. K. Brown, “Chapter 1: Introduction,” In: D. G. Neary, K. C. Ryan and L. F. DeBano, Eds., Technical Report RMRS-GTR-42, United States Department of Agriculture, Ogden, 2005, pp. 1-17.
 G. S. Campbell, J. D. Jungbauer, W. R. Bidlake and R. D. Hungerford, “Predicting the Effect of Temperature on Soil Thermal Conductivity,” Soil Science, Vol. 158, No. 5, 1994, pp. 307-313.
 O. T. Farouki, “Thermal Properties of Soils”. Trans Tech Publications, Clausthal-Zellerfeld, 1986.
 D. A. DeVries, “Thermal Properties of Soils,” In: W. R. van Wijk, Ed., Physics of Plant Environment, John Wiley & Sons, New York, 1963, pp. 210-235.
 G. S. Campbell and J. M. Norman, “An Introduction to Environmental Biophysics,” 2nd Edition, Springer-Verlag: NewYork, 1998.
 S. I. M.Skinner, R. L. Halstead and J. E. Brydon, “Quantitative Manometric Determination of Calcite and Dolomite in Soils and Limestones,” Canadian Journal of Soil Science, Vol. 39, No. 2, 1959, pp. 197-204.
 Ministerio de Agricultura, Pesca y Alimentación, “Métodos Oficiales de Análisis Tomo III, Secretaría General Técnica,” M.A.P.A., Madrid, 1986.
 A. Walkley and I. A. Black, “An Examination of the Degtjareff Method for Determining Soil Organic Matter and a Proposed Modification of the Chromic Acid Titration Method,” Soil Science, Vol. 37, No. 1, 1934, pp. 29- 38. doi:/10.1097/00010694-193401000-00003
 C. M. Rubio, R. Josa, J. M. Villar, F. Fonseca and F. Ferrer, “Development of Laboratory Analytical Procedures to Determine Thermal Properties in Soils,” Proceedings of III International Meeting of the European Confederation of Soil Science Societies EUROSOIL, Vienna, 28 August 2008, p. 308.
 C. M. Rubio, R. Josa, D. R. Cobos, C. S. Campbell and F. Ferrer, “Hysteretic Behaviour of Thermal Properties on Porous Media Advances in Studies on Desertification,” University of Murcia, Murcia, 2009.
 S. Shiozawa and G. S. Campbell, “Soil Thermal Conductivity,” Remote Sensing Reviews, Vol. 5, No. 1, 1990, pp. 301- 310.
 Soil Survey Staff, “Keys to Soil Taxonomy,” 8th Edition, US. Government Printing Office, Washington DC, 1998.
 N. H. Abu-Hamdeh and R. C. Reeder, “Soil Thermal Conductivity: Effects of Density, Moisture, Salt Concentration and Organic Matter,” Soil Science Society of America Journal, Vol. 64, No. 4, 2000, pp. 1285-1290.
 T. F. Wall, S. P. Bhattacharya, D. K. Zhang, R. P. Gupta and X. He, “The Properties and Thermal Effects of Ash Deposits in Coal-Fired Furnaces,” Progress in Energy and Combustion Science, Vol. 19, No. 6, 1993, pp. 487-504.
 K. Noborio and K. J. McInnes, “Thermal Conductivity of Salt Affected Soils,” Soil Science Society of America Journal, Vol. 57, No. 2, 1993, pp. 329-334.
 L. R. Iverson and T. F. Hutchinson, “Soil Temperature and Moisture Fluctuations during and after Prescribed Fire in Mixed-Oak Forest, USA,” Natural Areas Journal, Vol. 22, No. 4, 2002, pp. 296-304.