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Tree ring responses to elevated CO 2 and increased N deposition in Picea abies
Author(s) -
HÄTTENSCHWILER S.,
SCHWEINGRUBER F. H.,
KÖRNER Ch.
Publication year - 1996
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.1365-3040.1996.tb00015.x
Subject(s) - picea abies , deposition (geology) , lignin , dendrochronology , nutrient , nitrogen , chemistry , forest ecology , ecosystem , horticulture , environmental science , agronomy , zoology , botany , biology , ecology , paleontology , sediment , organic chemistry
Four‐ to seven‐year‐old spruce trees ( Picea abies ) were exposed to three CO 2 concentrations (280, 420 and 560 cm 3 m −3 ) and three rates of wet N deposition (0, 30 and 90 kg ha −1 year −1 ) for 3 years in a simulated montane forest climate. Six trees from each of six clones were grown in competition in each of nine 100 × 70 × 36 cm model ecosystems with nutrient‐poor natural forest soil. Stem dises were analysed using X‐ray densitometry. The radial stem increment was not affected by [CO 2 ] but increased with increasing rates of N deposition. Wood density was increased by [CO 2 ], but decreased by N deposition. Wood‐starch concentration increased, and wood nitrogen concentration decreased with increasing [CO 2 ], but neither was affected by N deposition. The lignin concentration in wood was affected by neither [CO 2 ] nor N deposition. Our results suggest that, under natural growth conditions, rising atmospheric [CO 2 ] will not lead to enhanced radial stem growth of spruce, but atmospheric N deposition will, and in some regions is probably already doing so. Elevated [CO 2 ], however, will lead to denser wood unless this effect is compensated by massive atmospheric N deposition. If can be speculated that greater wood density under elevated [CO 2 ] may alter the mechanical properties of wood, and higher ratios of C/N and lignin/N in wood grown at elevated [CO 2 ] may affect nutrient cycles of forest ecosystems.