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Interpreting tree responses to thinning and fertilization using tree‐ring stable isotopes
Author(s) -
Brooks J. Renée,
Mitchell Alan K.
Publication year - 2011
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2010.03627.x
Subject(s) - thinning , canopy , human fertilization , microclimate , water use efficiency , isotopes of carbon , stable isotope ratio , photosynthesis , ecology , agronomy , environmental science , biology , botany , physics , quantum mechanics , total organic carbon
Summary• Carbon sequestration has focused renewed interest in understanding how forest management affects forest carbon gain over timescales of decades, and yet details of the physiological mechanisms over decades are often lacking for understanding long‐term growth responses to management. • Here, we examined tree‐ring growth patterns and stable isotopes of cellulose (δ 13 C cell and δ 18 O cell ) in a thinning and fertilization controlled experiment where growth increased substantially in response to treatments to elucidate physiological data and to test the dual isotope approach for uses in other locations. • δ 13 C cell and δ 18 O cell results indicated that fertilization caused an increase in intrinsic water‐use efficiency through increases in photosynthesis ( A ) for the first 3 yr. The combination treatment caused a much larger increase in A and water‐use efficiency. Only the thinning treatments showed consistent significant increases in δ 18 O cell above controls. Changes in canopy microclimate are the likely drivers for δ 18 O cell increases with decreases in relative humidity and increases in leaf temperature associated with thinning being the most probable causes. • Tree‐ring isotopic records, particularly δ 13 C cell , remain a viable way to reconstruct long‐term physiological mechanisms affecting tree carbon gain in response to management and climate fluctuations.