ENSO and NAO affect long‐term leaf litter dynamics and stoichiometry of Scots pine and European beech mixedwoods

Autor: Ester González de Andrés, Biing T. Guan, J. Bosco Imbert, Federico J. Castillo, Juan A. Blanco, Yueh-Hsin Lo
Přispěvatelé: Universidad Pública de Navarra. Departamento de Ciencias, Nafarroako Unibertsitate Publikoa. Zientziak Saila
Rok vydání: 2019
Předmět:
Zdroj: Academica-e: Repositorio Institucional de la Universidad Pública de Navarra
Universidad Pública de Navarra
Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
instname
ISSN: 1365-2486
1354-1013
Popis: Litterfall dynamics (production, seasonality and nutrient composition) are key factors influencing nutrient cycling. Leaf litter characteristics are modified by species composition, site conditions and water availability. However, significant evidence on how large-scale, global circulation patterns affect ecophysiological processes at tree and ecosystem level remains scarce due to the difficulty in separating the combined influence of different factors on local climate and tree phenology. To fill this gap, we studied links between leaf litter dynamics with climate and other forest processes, such as tree-ring width (TRW) and intrinsic water-use efficiency (iWUE) in two mixtures of Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.) in the south-western Pyrenees. Temporal series (18 years) of litterfall production and elemental chemical composition were decomposed following the ensemble empirical mode decomposition (EEMD) method and relationships with local climate, large-scale climatic indices, TRW and Scots pine´s iWUE were assessed. Temporal trends in N:P ratios indicated increasing P-limitation of soil microbes, thus affecting nutrient availability, as the ecological succession from a pine-dominated to a beech-dominated forest took place. A significant influence of large-scale patterns on tree-level ecophysiology was explained through the impact of the North Atlantic Oscillation (NAO) and El Niño – Southern Oscillation (ENSO) on water availability. Positive NAO and negative ENSO were related to dry conditions and, consequently, to early needle shedding and increased N:P ratio of both species. Autumn storm activity appears to be related to premature leaf abscission of European beech. Significant cascading effects from large-scale patterns on local weather influenced pine TRW and iWUE. These variables also responded to leaf stoichiometry fallen three years prior to tree-ring formation. Our results provide evidence of the cascading effect that variability in global climate circulation patterns can have on ecophysiological processes and stand dynamics in mixed forests. Ministerio de Economía y Competitividad, Grant/Award Number: AGL2012-33465, AGL2016-76463-P, BES-2013-066705 and RYC-2011-08082; FP7 People: Marie-Curie Actions, Grant/Award Number: CIG-2012-326718-ECOPYREN3; H2020 Marie Skłodowska-Curie Actions, Grant/Award Number: EF-2014-656810-DENDRONUTRIENT.
Databáze: OpenAIRE
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