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Fast response of Scots pine to improved water availability reflected in tree‐ring width and δ 13 C
Author(s) -
EILMANN BRITTA,
BUCHMANN NINA,
SIEGWOLF ROLF,
SAURER MATTHIAS,
CHERUBINI PAOLO,
RIGLING ANDREAS
Publication year - 2010
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.2010.02153.x
Subject(s) - scots pine , biomass (ecology) , environmental science , irrigation , dendrochronology , isotope , stable isotope ratio , biology , ecology , agronomy , botany , pinus <genus> , physics , paleontology , quantum mechanics
Drought‐induced forest decline, like the Scots pine mortality in inner‐Alpine valleys, will gain in importance as the frequency and severity of drought events are expected to increase. To understand how chronic drought affects tree growth and tree‐ring δ 13 C values, we studied mature Scots pine in an irrigation experiment in an inner‐Alpine valley. Tree growth and isotope analyses were carried out at the annual and seasonal scale. At the seasonal scale, maximum δ 13 C values were measured after the hottest and driest period of the year, and were associated with decreasing growth rates. Inter‐annual δ 13 C values in early‐ and latewood showed a strong correlation with annual climatic conditions and an immediate decrease as a response to irrigation. This indicates a tight coupling between wood formation and the freshly produced assimilates for trees exposed to chronic drought. This rapid appearance of the isotopic signal is a strong indication for an immediate and direct transfer of newly synthesized assimilates for biomass production. The fast appearance and the distinct isotopic signal suggest a low availability of old stored carbohydrates. If this was a sign for C‐storage depletion, an increasing mortality could be expected when stressors increase the need for carbohydrate for defence, repair or regeneration.