Short‐ and medium‐term evolution of soil properties in Atlantic forest ecosystems affected by wildfires

Abstract

The immediate effect of low and high severity wildfires on the main soil properties, as well as their short‐ and medium‐term evolution under field conditions, was examined. The study was performed with three pine forest soils (two Leptosols and one Humic Cambisol, developed over granite and basic schist, respectively), located in the Atlantic humid temperate zone (Galicia, NW Spain). Samples were collected from the A‐horizon (0–5 cm depth) of the burnt and the corresponding unburnt soils, immediately and 3, 6 and 12 months after the wildfires. Most properties analysed exhibit immediate fire‐induced changes and different evolution depending on fire severity and soil type. In general, immediately after the fire pH and soil properties related to nutrients availability increased and cation exchange capacity decreased, whereas properties related to soil organic matter content (C, N, Fe and Al oxides) had a variable effect depending mainly on the soil studied; all these modifications were accentuated by fire severity. These effects were attenuated in the short term in the soil affected by a low severity wildfire, but they lasted for at least 1 year in the soils affected by high severity wildfires, particularly in the Leptosols. The results showed the importance of the fire as a disturbance agent in the dynamic of nutrients and soil organic matter that is directly related with soil quality in the Galician forest ecosystems. Copyright © 2011 John Wiley & Sons, Ltd.

Revisión de las investigaciones a nivel molecular sobre el impacto del fuego en la materia orgánica del suelo: progresos en el siglo XXI

“…En el caso de 389 la materia orgánica del suelo (MOS) se han observado cambios en los contenidos totales de carbono (C) y nitrógeno (N), alteraciones estructurales en las fracciones húmicas, descenso en su biodegrabilidad, incremento en la hidrofobicidad, etc. (González-Pérez et al, 2004;Almendros y González-Vila, 2012;Martín et al, 2012). Dichos cambios presentan gran importancia a nivel global, puesto que la MOS constituye la mayor reserva de C de la superficie de la Tierra, de tal forma que incluso pequeñas alteraciones en su contenido total y sobre todo en su biodegradabilidad, se traducen en cambios notables en los balances de materia y energía de los ciclos del C. En un incendio forestal se liberan a la atmósfera grandes cantidades de CO 2 .…”

Modelling soil organic carbon stocks in global change scenarios: a CarboSOIL application

“…These areas are particularly vulnerable since are usually burnt areas or areas under erosive processes ). An increase on the occurrence and the intensity of forest fires is predicted in future climate scenarios, which might largely affect soil organic carbon quality and dynamics (Martín et al, 2012). However, in contrast to other land use types, the CarboSOIL model predicted minor losses of SOC stocks in "forests", which can be explained by a higher relative aboveground allocation.…”

AGREGAÇÃO DE UM CAMBISSOLO HÚMICO EM POVOAMENTOS DE <i>Pinus taeda</i> L. COM DIFERENTES ROTAÇÕES

“…Dessa forma, a matéria orgânica incorporada à camada mineral superficial do solo tende a atingir quantidades em equilíbrio com as condições do ambiente, conforme se observa na área-testemunha; confirmando a relação existente entre o conteúdo de carbono e a idade do florestamento (BOCHNER et al, 2008;FACHINI, 2012). Chen e Shrestha (2012) perceberam baixa estabilidade de agregados logo após as práticas de corte raso e queima, no entanto, os efeitos foram sendo reduzidos ao longo do tempo, corroborando com Martín, Díaz-Raviña, Carballas (2012). Considera-se ainda, a importância da atuação das raízes de absorção nas camadas superficiais, que possuem elevada taxa de renovação e atuam ligando-se aos minerais do solo por meio da liberação de exsudatos orgânicos.…”