Organic matter is the soil component most sensitive to fire, being the fuel on the ground and below. It is affected by fire in terms of both abundance and composition. Incomplete combustion yields condensed carbon forms characterized by higher recalcitrance to biological and chemical attack compared to the parent material. In this study, thermogravimetry (TG-DTG), differential scanning calorimetry (DSC), attenuated total reflectance/Fourier transform infrared spectroscopy (ATR/FT-IR), and Raman spectroscopy were applied to (1) charcoal particles accumulated on the ground, (2) the top 10 cm of soil, and (3) the SOM extracted using an alkaline solution, to investigate the wildfire effect on the organic pool of the loamy and sub-acid soil of a maritime pine (Pinus pinaster Ait.) forest. The same investigations were performed on the litter layer and the mineral soil of an adjacent unburnt area, similar to the burnt one before fire occurrence. TG-DTG and DSC measurements highlighted an accumulation of soil organic matter (SOM) in the burnt soil, which suggests an incorporation of partly charred necromass into soil and the formation of pyrogenic highly refractory organic matter, i.e. black carbon. The ATR/FT-IR showed changes in the fire affected extractable SOM compatible with the formation of stable N containing compounds in the fire affected extractable SOM, which was well confirmed also by the presence of CN groups vibration in the Raman spectrum. The combined application of thermal and spectroscopic techniques resulted to be highly useful to rapidly estimate many of the effects of fire on soil organic matter.

Application of thermal and spectroscopic techniques to assess fire-induced changes to soil organic matter in a Mediterranean forest

FRANCIOSO, ORNELLA;DI FOGGIA, MICHELE;BONORA, SERGIO;
2014

Abstract

Organic matter is the soil component most sensitive to fire, being the fuel on the ground and below. It is affected by fire in terms of both abundance and composition. Incomplete combustion yields condensed carbon forms characterized by higher recalcitrance to biological and chemical attack compared to the parent material. In this study, thermogravimetry (TG-DTG), differential scanning calorimetry (DSC), attenuated total reflectance/Fourier transform infrared spectroscopy (ATR/FT-IR), and Raman spectroscopy were applied to (1) charcoal particles accumulated on the ground, (2) the top 10 cm of soil, and (3) the SOM extracted using an alkaline solution, to investigate the wildfire effect on the organic pool of the loamy and sub-acid soil of a maritime pine (Pinus pinaster Ait.) forest. The same investigations were performed on the litter layer and the mineral soil of an adjacent unburnt area, similar to the burnt one before fire occurrence. TG-DTG and DSC measurements highlighted an accumulation of soil organic matter (SOM) in the burnt soil, which suggests an incorporation of partly charred necromass into soil and the formation of pyrogenic highly refractory organic matter, i.e. black carbon. The ATR/FT-IR showed changes in the fire affected extractable SOM compatible with the formation of stable N containing compounds in the fire affected extractable SOM, which was well confirmed also by the presence of CN groups vibration in the Raman spectrum. The combined application of thermal and spectroscopic techniques resulted to be highly useful to rapidly estimate many of the effects of fire on soil organic matter.
G. Mastrolonardo; O. Francioso; M. Di Foggia; S.Bonora; C. Rumpel; G. Certini
File in questo prodotto:
Eventuali allegati, non sono esposti

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11585/282716
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 24
  • ???jsp.display-item.citation.isi??? 24
social impact