Chemical composition and origin source of soil organic matter under

This study deals with the chemical characterization of soil organic matter (SOM) under different ground covers from a Mediterranean climate (Andalusia, South Spain), for it using techniques of analytical pyrolysis, with this techniques, we could find that organic matter consists mainly of seven chemical families, as they are, alkanes / alkenes, fatty acids, aromatic, lignin, steranes, sugars and peptides. Also we had been used different approaches for the isotopic signature study of stable light elements in bulk (low-complexity) samples. Light element isotope ratios (δ15N, δ13C, δ18O and δD) were measured in the whole soil samples (EA/TC-IRMS) and δ13C and δD values were also estimated in a number of specific compounds-previously identified by Py-GC/MS released after pyrolysis (Py-GC-(FID)-C\TC-IRMS)