Structural heterogeneity of vegetation fire ash

Abstract

Any wildfire generates ash, the solid residue derived from burning biomass. Vegetation fire ash consists of charred organic material, charcoal, and inorganic mineral substances. Recent studies identified ash deposits as a dual system: soil and ash strata. The addition of ash to the soil profile alters soil properties and dynamics. A thorough analysis of ash–soil profile reveals a structural appearance of thin laminas. The laminas differ in a variety of physical properties and mineral composition. This research aims at assessing the unique properties of ash–soil profiles by performing an infrared spectroscopic study and statistical analysis. For that purpose, several laboratory experiments were conducted. The paper presents semiquantitative results of spectral analysis calculated by 4 statistical methods. The results indicate a well‐established laminar structure of the ash and evaluate the characteristics of each lamina. The proposed methodology was examined under real‐world conditions; a field experiment of 2‐m2 parcel with in situ O horizon was flamed and burned out. The field samples illustrated the formation of microlaminas, which proved to be similar to the laboratory samples. This detailed approach may promote a better understanding of the complex nature to the ash, the ash–soil interactions and its effect on the edaphic ecosystem.

Total Carbon Content Assessed by UAS Near-Infrared Imagery as a New Fire Severity Metric

“…(3) The SVC correction-the at-sensor radiance is converted into accurate reflectance by applying four stages: normalization of the albedo sequence (F1) inspected by QIs, radiometric calibration gain using the net ground-truth reflectance (F2), applying a model-based atmospheric correction (F3) using ATCOR5 model, ACORN and empirical line method, and spectral polishing using the net ground0truth reflectance (F4 C and N content in the top-ash layer was quantified. While organic C is measured using elemental analyzers, many studies, e.g., [59,65,66] reported that DR-FTIR spectroscopy yields good estimates for PyC. To quantify the area of the aromatic and aliphatic n(CH) bands, the spectra were baseline corrected in the 3200 to 2700 cm −1 region using a quartic fitting function.…”