Testing the ability of visual indicators of soil burn severity to reflect changes in soil chemical and microbial properties in pine forests and shrubland

• Published in: Plant and soil Vol. 369; no. 1/2; pp. 73 - 91
• Main Authors: Vega, José A., Fontúrbel, Teresa, Merino, Agustín, Fernández, Cristina, Ferreiro, Andrea, Jiménez, Enrique
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01-08-2013; Springer Netherlands; Springer Nature B.V
• Subjects: Acid soils; Agronomy. Soil science and plant productions; Ammonification; Animal, plant and microbial ecology; Biochemistry and biology; Biogeochemistry; Biological and medical sciences; Biological properties; Biomass; Biomedical and Life Sciences; Chemical, physicochemical, biochemical and biological properties; Coniferous forests; Ecology; Environmental aspects; Fire severity; Forest & brush fires; Forest fires; Forest soils; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Life Sciences; Microbiology; Mineral soils; Mineralization; Nitrification; Organic soils; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Pine; Plant Physiology; Plant Sciences; Reforestation; Regular Article; Soil biochemistry; Soil chemistry; Soil microbiology; Soil microorganisms; Soil science; Soil Science & Conservation; Soil structure; Soil surfaces; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Soils; Wildfires; Spain; Wildfire; Soil burn severity; SOC; pH; Soil nutrients; Acid phosphatase; Microbial biomass; Post-fire rehabilitation criteria; Biological properties; Microbial activity; Phosphoric monoester hydrolases; Esterases; Pinus; Inorganic element; Criterion; Gymnospermae; Shrubbery; Ability; Enzyme; Woody plant; Biological activity; Indicator; Soils; Chemistry; Vegetation type; Vegetation; Hydrolases; Coniferales; Spermatophyta; Vegetation fire; Shrubland; Rehabilitation; Fire effect; Physicochemical properties; Coniferous forest
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-012-1532-9

Aims Areas affected by wildfire comprise spatially complex mosaics of burned patches in which a wide range of burn severities coexist. Rapid diagnosis of the different levels of soil burn severity and their extents is essential for designing emergency post-fire rehabilitation treatments. The main objective of this study was to determine whether visual signs of soil burn severity levels are related to changes in soil chemical and microbial properties immediately after fire. Methods Eight areas affected by wildfires in NW Spain were selected immediately after fire, and soil chemical and biological properties (pH, extractable Ca, K, Mg and P, SOC, total N, δC, basal soil respiration, Cmic, phosphatase activity, extractable NH₄⁺ and NO₃⁻, ammonification and nitrification rates and potential N mineralization) were analysed in relation to five levels of soil burn severity (0: Unburned; 1: Oa layer partially or totally intact; 2: Oa layer totally charred; 3: Bare soil and soil structure unaffected; 4: Bare soil and soil structure affected; 5: Bare soil and surface soil structure and colour altered). Results The five visually assessed levels of soil burn severity adequately reflected changes in SOC, pH, and phosphatase activity, which varied gradually with increasing soil burn severity. However, alterations in certain indicators related to the soil organic quality (C/N, Cmic/SOC, qCO₂, δ¹³C) were only detected in the most severely burned areas. Discriminant analysis revealed that the best combination of variables was acid phosphatase activity, SOC and pH, which correctly classified between 64 and 76 % of samples, depending on the levels of soil burn severity considered. Conclusions The results showed that the proposed soil burn severity categories may be useful for indicating the degree of degradation of important soil chemical and microbiological properties in sites similar to the study area. This, in combination with other factors, will allow prioritization of areas for rehabilitation.