%0 Journal Article
%T Wildfires, soil carbon balance and resilient organic matter in Mediterranean ecosystems. A review Los incendios forestales, el balance de carbono en el suelo y la materia org¨¢nica resiliente en ecosistemas mediterr¨¢neos. Una revision Inc¨ºndios florestais, balan o do carbono no solo e mat¨¦ria organica resiliente em ecossistemas mediterranicos. Uma revisao
%A Gonzalo Almendros
%A Francisco Javier Gonz¨¢lez-Vila
%J Spanish Journal of Soil Science
%D 2012
%I Universia
%R 10.3232/sjss.2012.v2.n2.01
%X A review of the effects of wildfires on Mediterranean soils was carried out with special emphasis on the biogeochemical processes involved in soil C sequestration. Modifications to the composition and properties of soil humic substances and related resilient C-forms in soil resulting from fires were also discussed. The systematic effects of fires on soil organic matter (SOM) mainly involve changes to its solubility and colloidal properties, selective thermal degradation, structural condensation and the cyclization of soil C and N-forms. These effects represent an increase in the biogeochemical stability and chemical diversity of the SOM after the thermal generation of structures that are not found in soils unless they are affected by fire. Non-systematic effects also depend on local environmental constraints and on the great differences in fire intensities and propagation patterns. The effects of fire were also discussed, taking advantage of the results of laboratory simulation experiments. This approach is indispensable for differentiating fire intrinsic effects on soil from those produced by fire-induced inputs of charred necromass and the subsequent effects of soil erosion. In some cases, the characteristic properties acquired by post-fire soils can be explained in terms of molecular-level features of humic substances and, in particular, those concerning resistance to biodegradation, cation exchange capacity, N-availability, soil water repellence and aggregate stability.   En este trabajo se lleva a cabo una revisi¨®n sobre los efectos de los incendios forestales en los suelos mediterr¨¢neos, con especial ¨¦nfasis sobre sus efectos en los procesos biogeoqu¨ªmicos de acumulaci¨®n o secuestro de C en el suelo. Asimismo, se revisan los efectos de los incendios sobre la composici¨®n y propiedades de las sustancias h¨²micas y otras formas resilientes de C en el suelo. Las principales efectos sistem¨¢ticos del fuego sobre la materia org¨¢nica incluyen cambios en su solubilidad y propiedades coloidales, as¨ª como degradaci¨®n t¨¦rmica selectiva, condensaciones estructurales y ciclaci¨®n de formas de C y N en el suelo. Estos efectos, en conjunto, se consideran responsables del aumento en la diversidad qu¨ªmica de la materia org¨¢nica debido a la generaci¨®n t¨¦rmica de nuevos compuestos inexistentes en los correspondientes suelos no afectados por el fuego. Adem¨¢s de ello, deben considerarse los efectos no sistem¨¢ticos del fuego, que dependen de las condiciones ambientales locales y la amplia diversidad de los tipos de incendios. Tambi¨¦n se discuten los resultados de estudios
%K Humic substances
%K thermal impact
%K burnings
%K soil carbon sequestration
%K Sustancias h¨²micas
%K impacto t¨¦rmico
%K quemas
%K secuestro de carbono en el suelo
%K Substancias h¨²micas
%K impacto t¨¦rmico
%K queimadas
%K sequestro de carbono no solo
%U http://sjss.universia.net/pdfs_revistas/articulo_259_1342182531937.pdf