Per citar aquest document: http://ddd.uab.cat/record/131766
The role of defoliation and root rot pathogen infection in driving the mode of drought-related physiological decline in Scots pine (Pinus sylvestris L.)
Aguadé Vidal, David (Centre de Recerca Ecològica i Aplicacions Forestals)
Poyatos López, Rafael (Centre de Recerca Ecològica i Aplicacions Forestals)
Gómez Gallego, Mireia (Centre Tecnològic Forestal de Catalunya)
Oliva, Jonàs (Swedish University of Agricultural Sciences. Department of Forest Mycology and Plant Pathology)
Martínez Vilalta, Jordi, 1975- (Centre de Recerca Ecològica i Aplicacions Forestals)

Data: 2015
Resum: Drought-related tree die-off episodes have been observed in all vegetated continents. Despite much research effort, however, the multiple interactions between carbon starvation, hydraulic failure and biotic agents in driving tree mortality under field conditions are still not well understood. We analysed the seasonal variability of non-structural carbohydrates (NSCs) in four organs (leaves, branches, trunk and roots), the vulnerability to embolism in roots and branches, native embolism (percentage loss of hydraulic conductivity (PLC)) in branches and the presence of root rot pathogens in defoliated and non-defoliated individuals in a declining Scots pine (Pinus sylvestris L. ) population in the NE Iberian Peninsula in 2012, which included a particularly dry and warm summer. No differences were observed between defoliated and non-defoliated pines in hydraulic parameters, except for a higher vulnerability to embolism at pressures below -2 MPa in roots of defoliated pines. No differences were found between defoliation classes in branch PLC. Total NSC (TNSC, soluble sugars plus starch) values decreased during drought, particularly in leaves. Defoliation reduced TNSC levels across tree organs, especially just before (June) and during (August) drought. Root rot infection by the fungal pathogen Onnia P. Karst spp. was detected but it did not appear to be associated to tree defoliation. However, Onnia infection was associated with reduced leaf-specific hydraulic conductivity and sapwood depth, and thus contributed to hydraulic impairment, especially in defoliated pines. Infection was also associated with virtually depleted root starch reserves during and after drought in defoliated pines. Moreover, defoliated and infected trees tended to show lower basal area increment. Overall, our results show the intertwined nature of physiological mechanisms leading to drought-induced mortality and the inherent difficulty of isolating their contribution under field conditions.
Nota: Número d'acord de subvenció MICINN/CGL2010-16373
Nota: Número d'acord de subvenció MICINN/CSD2008-00040
Nota: Número d'acord de subvenció MECD/FPU-AP2010-4573
Drets: Tots els drets reservats
Llengua: Anglès
Document: article ; recerca ; acceptedVersion
Matèria: Die-off ; Fungi pathogen ; Global change ; Hydraulic failure ; Non-structural carbohydrates
Publicat a: Tree Physiology, Vol. 35 Issue 3 (March 2015) , p. 229-242, ISSN 0829-318X

DOI: 10.1093/treephys/tpv005


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Documents de recerca > Documents dels grups de recerca de la UAB > Centres i grups de recerca (producció científica) > Ciències > CREAF (Centre de Recerca Ecològica i d'Aplicacions Forestals)
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 Registre creat el 2015-04-23, darrera modificació el 2016-06-04



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