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Orientador(es)
Resumo(s)
Soils constitute the major reservoir of mercury (Hg) in terrestrial ecosystems, whose stability may be threatened
by wildfires. This research attempts to look at the effect of prescribed fire on the presence of Hg in a shrubland
ecosystem from NE Portugal, delving into its relationship with soil aggregate size and the molecular composition
of soil organic matter (SOM). During the prescribed fire, on average 347 mg Hg ha 1 were lost from the burnt
aboveground biomass of shrubs and 263 mg Hg ha 1 from the combustion of the soil organic horizon. Overall,
Hg concentration and pools in the mineral soil did not show significant changes due to burning, which highlights
their role as long-term Hg reservoirs. The higher Hg concentrations found in smaller aggregates (<0.2 mm)
compared to coarser ones (0.5–2 mm) are favored by the higher degree of organic matter decomposition (low C/
N ratio), rather than by greater total organic C contents. The Hg-enriched finest fraction of soil (<0.2 mm) could
be more prone to be mobilized by erosion, whose potential arrival to water bodies increases the environmental
concern for the Hg present in fire-affected soils. The SOM quality (molecular composition) and the main organic
families, analyzed by Fourier-transform infrared spectroscopy in combination with multivariate statistical
Descrição
Palavras-chave
Hg Prescribed burning Re-emission ATR-FT/IR Chemometrics SOM
Contexto Educativo
Citação
Méndez-López, Melissa; Jiménez-Morillo, Nicasio Tomás; Fonseca, Felicia; Figueiredo, Tomás de; Parente-Sendín, Andrea; Alonso-Vega, Flora; Arias-Estévez, Manuel; Nóvoa-Muñoz, Juan Carlos (2023). Mercury mobilization in shrubland after a prescribed fire in NE Portugal: Insight on soil organic matter composition and different aggregate size. Science of The Total Environment. ISSN 0048-9697. 904, p. 1-15
Editora
Elsevier