Molecular Characterization of Burned Organic Matter at Different Soil Depths and Its Relationship with Soil Water Repellency: A Preliminary Result

Soil water repellency (hydrophobicity) prevents from wetting or infiltrating soils, triggering changes in the ecosystems. This physical property is directly correlated to erodibility grade of a soil. Wildfire events may develop, enhance, destroy soil hydrophobicity, modifying and increasing loss its most reactive layer (organic matter). To assess main organic family compounds (biomarkers) surrogates fire-induced repellency, study was carried out on fire-affected under eucalyptus canopy at two depths (0–2 2–5 cm) Portugal. The potential measured using drop penetration time (WDPT) test. molecular characterization hydrophobic biomarkers analytical pyrolysis (Py-GC/MS) combination with multivariate statistical analysis (PCA, MLR). upper burned displayed significant contribution fresh biomass (lignin polysaccharides), while deepest (2–5 one showed more humified matter (lipids). hydrophobicity non-polar compounds, such as lipids polycyclic aromatic hydrocarbons (PAHs), inversely unspecific compounds. mass spectrometry techniques chemometric allowed obtaining preliminary forecast model degree samples canopy. approach opens door developing sensitive mathematical models predict alteration other properties induced by fires.