Changes in soil bacterial community triggered by drought-induced gap succession preceded changes in soil C stocks and quality
Curiel Yuste, Jorge (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Barba, Josep (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Fernandez-Gonzalez, Antonio José (Consejo Superior de Investigaciones Científicas. Estación Experimental del Zaidín)
Fernandez-Lopez, Manuel (Consejo Superior de Investigaciones Científicas. Estación Experimental del Zaidín)
Mattana, Stefania (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Martínez Vilalta, Jordi, 1975- (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Nolis Fañanas, Pau (Universitat Autònoma de Barcelona. Servei de Ressonància Magnètica Nuclear)
Lloret Maya, Francisco (Centre de Recerca Ecològica i d'Aplicacions Forestals)

Date:	2012
Abstract:	The aim of this study was to understand how drought-induced tree mortality and subsequent secondary succession would affect soil bacterial taxonomic composition as well as soil organic matter (SOM) quantity and quality in a mixed Mediterranean forest where the Scots pine (Pinus sylvestris) population, affected by climatic drought-induced die-off, is being replaced by Holm-oaks (HO; Quercus ilex). We apply a high throughput DNA pyrosequencing technique and 13 C solid-state Nuclear Magnetic Resonance (CP-MAS 13 C NMR) to soils within areas of influence (defined as an surface with 2-m radius around the trunk) of different trees: healthy and affected (defoliated) pines, pines that died a decade ago and healthy HOs. Soil respiration was also measured in the same spots during a spring campaign using a static close-chamber method (soda lime). A decade after death, and before aerial colonization by the more competitive HOs have even taken place, we could not find changes in soil C pools (quantity and/or quality) associated with tree mortality and secondary succession. Unlike C pools, bacterial diversity and community structure were strongly determined by tree mortality. Convergence between the most abundant taxa of soil bacterial communities under dead pines and colonizer trees (HOs) further suggests that physical gap colonization was occurring below-ground before above-ground colonization was taken place. Significantly higher soil respiration rates under dead trees, together with higher bacterial diversity and anomalously high representation of bacteria commonly associated with copiotrophic environments (r-strategic bacteria) further gives indications of how drought-induced tree mortality and secondary succession were influencing the structure of microbial communities and the metabolic activity of soils.
Grants:	Ministerio de Economía y Competitividad CGL2010-16373 Ministerio de Economía y Competitividad CGL2009-08101 Ministerio de Ciencia e Innovación CSD2008-00040
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Climate change ; Drought ; Ecosystem functioning ; Forest dieback ; Gap colonization ; Microbial diversity ; Nutrient cycling ; Pyrosequencing ; Tree mortality
Published in:	Ecology and evolution, Vol. 2 (Nov. 2012) , p. 3016-3031, ISSN 2045-7758

DOI: 10.1002/ece3.409
PMID: 23301169

16 p, 1.6 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > CREAF (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Articles > Research articles
Articles > Published articles