Site-specific water-use strategies of mountain pine and larch to cope with recent climate change

Описание

Тип публикации: статья из журнала

Год издания: 2016

Идентификатор DOI: 10.1093/treephys/tpw060

Ключевые слова: delta C-13 and delta O-18 in wood, delta O-18 in needle, soil and xylem water, intrinsic water-use efficiency, pine decline, tree-ring width

Аннотация: We aim to achieve a mechanistic understanding of the eco-physiological processes in Larix decidua and Pinus mugo var. uncinata growing on north- and south-facing aspects in the Swiss National Park in order to distinguish the short- and long-term effects of a changing climate. To strengthen the interpretation of the delta O-18 signaПоказать полностьюl in tree rings and its coherence with the main factors and processes driving evaporative-delta O-18 needle water enrichment, we analyzed the delta O-18 in needle, xylem and soil water over the growing season in 2013 and applied the mechanistic Craig-Gordon model (1965) for the short-term responses. We found that delta O-18 needle water strongly reflected the variability of relative humidity mainly for larch, while only delta O-18 in pine xylem water showed a strong link to delta O-18 in precipitation. Larger differences in offsets between modeled and measured delta O-18 needle water for both species from the south-facing aspects were detected, which could be explained by the high transpiration rates. Different soil water and needle water responses for the two species indicate different water-use strategies, further modulated by the site conditions. To reveal the long-term physiological response of the studied trees to recent and past climate changes, we analyzed delta C-13 and delta O-18 in wood chronologies from 1900 to 2013. Summer temperatures as well as summer and annual amount of precipitations are important factors for growth of both studied species from both aspects. However, mountain pine trees reduced sensitivity to temperature changes, while precipitation changes come to play an important role for the period from 1980 to 2013. Intrinsic water-use efficiency (WUEi) calculated for larch trees since the 1990s reached a saturation point at elevated CO2. Divergent trends between pine WUEi and delta O-18 are most likely indicative of a decline of mountain pine trees and are also reflected in decoupling mechanisms in the isotope signals between needles and tree-rings.

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Издание

Журнал: TREE PHYSIOLOGY

Выпуск журнала: Vol. 36, Is. 8

Номера страниц: 942-953

ISSN журнала: 0829318X

Место издания: OXFORD

Издатель: OXFORD UNIV PRESS

Персоны

  • Churakova Olga V. (ETH, Inst Terr Ecosyst, Forest Ecol, Dept Environm Syst Sci, Univ Str 16, CH-8092 Zurich, Switzerland; Paul Scherrer Inst, CH-5232 Villigen, Switzerland; Univ Bern, Inst Geol Sci, Dendrolab Ch, Balzerstr 1 3, CH-3012 Bern, Switzerland)
  • Saurer Matthias (Paul Scherrer Inst, CH-5232 Villigen, Switzerland)
  • Bryukhanova Marina V. (SB RAS, VN Sukachev Inst Forest, Akademgorodok 660036, Russia; Siberian Fed Univ, 79 Svobodny Pr, Krasnoyarsk 660041, Russia)
  • Siegwolf Rolf T. W. (Paul Scherrer Inst, CH-5232 Villigen, Switzerland)
  • Bigler Christof (ETH, Inst Terr Ecosyst, Forest Ecol, Dept Environm Syst Sci, Univ Str 16, CH-8092 Zurich, Switzerland)

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