Complex climate constraints of upper treeline formation in the Pyrenees
Fecha
2015Versión
Acceso abierto / Sarbide irekia
Tipo
Artículo / Artikulua
Versión
Versión aceptada / Onetsi den bertsioa
Identificador del proyecto
ES/6PN/CGL2011-26654
Impacto
|
10.1007/s00468-015-1176-5
Resumen
Alpine treelines are often induced by a threshold of minimum temperatures above which tree growth is generally not possible anymore. However, this worldwide pattern may not account for more drought-prone mountains, where changes in precipitation can also affect ecosystem functioning and productivity at higher elevations. Here, we aim to determine if tree-ring formation in ecotones along the Pyren ...
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Alpine treelines are often induced by a threshold of minimum temperatures above which tree growth is generally not possible anymore. However, this worldwide pattern may not account for more drought-prone mountains, where changes in precipitation can also affect ecosystem functioning and productivity at higher elevations. Here, we aim to determine if tree-ring formation in ecotones along the Pyrenees indeed primarily depends on temperature means or also reflects hydroclimatic changes. The mean duration of the growing season at Pyrenean treelines was 177 days, lasting from mid-May to early November, which corresponds to a mean root-zone temperature of 8.2 °C. Temperatures during the early and late growing season were most critical for mountain pine growth at highest elevations, and above average spring temperatures also contributed to radial enlargement of tracheids. Sites showing more similar soil temperatures also presented more similar long-term growth trends indicating that local conditions trace regional influences on growth. Nevertheless, more wet conditions in summer enhanced growth at treelines subjected to more Mediterranean influence and therefore having a higher summer water deficit. A broader perspective reveals that soil moisture availability during spring and summer, however, also influence ring width formation at other treelines located in mid-latitude mountains separating temperate and semi-arid biomes. Our results suggest re-evaluating the idea of purely temperature-limited treelines, especially in mid-latitude mountains that experience moisture seasonality or where precipitation decreases with increasing elevation. [--]
Materias
Basal area increment,
Drought stress,
Mediterranean,
Pinus uncinata,
Temperature,
Treeline
Editor
Springer
Publicado en
Trees, 2015, 29, 941-952
Departamento
Universidad Pública de Navarra. Departamento de Ciencias del Medio Natural /
Nafarroako Unibertsitate Publikoa. Natura Ingurunearen Zientziak Saila
Versión del editor
Entidades Financiadoras
E. González de Andrés acknowledges the support of an FPI fellowship (Economy and Innovation Ministry, Spain). J. Julio Camarero was supported by projects 387/2011 (OAPN, Agriculture an Environment Ministry, Spain) and CGL2011-26654 (Economy and Innovation Ministry, Spain). U. Büntgen was further supported by the Operational Programme of Education for Competitiveness of the Ministry of Education, Youth, and Sports of the Czech Republic (No. CZ.1.07/2.3.00/20.0248).