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Correlation of foliage and litter chemistry of sugar maple, Acer saccharum , as affected by elevated CO 2 and varying N availability, and effects on decomposition
Author(s) -
King J. S.,
Pregitzer K. S.,
Zak D. R.,
Kubiske M. E.,
Holmes W. E.
Publication year - 2001
Publication title -
oikos
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.672
H-Index - 179
eISSN - 1600-0706
pISSN - 0030-1299
DOI - 10.1034/j.1600-0706.2001.940303.x
Subject(s) - plant litter , chemistry , soil respiration , mineralization (soil science) , litter , nitrogen , soil carbon , nitrogen cycle , aceraceae , carbon dioxide , nutrient , agronomy , carbon cycle , ecosystem , nutrient cycle , cycling , environmental chemistry , respiration , maple , botany , soil water , ecology , biology , history , archaeology , organic chemistry
Rising atmospheric carbon dioxide has the potential to alter leaf litter chemistry, potentially affecting decomposition and rates of carbon and nitrogen cycling in forest ecosystems. This study was conducted to determine whether growth under elevated atmospheric CO 2 altered the quality and microbial decomposition of leaf litter of a widely distributed northern hardwood species at sites of low and high soil nitrogen availability. In addition, we assessed whether the carbon–nutrient balance (CNB) and growth differentiation balance (GDB) hypotheses could be extended to predict changes in litter quality in response to resource availability. Sugar maple ( Acer saccharum ) was grown in the field in open‐top chambers at 36 and 55 Pa partial pressure CO 2 , and initial soil mineralization rates of 45 and 348 μg N g −1 d −1 . Naturally senesced leaf litter was assessed for chemical composition and incubated in the laboratory for 111 d. Microbial respiration and the production of dissolved organic carbon (DOC) were quantified as estimates of decomposition. Elevated CO 2 and low soil nitrogen resulted in higher litter concentrations of nonstructural carbohydrates and condensed tannins, higher C/N ratios and lower N concentrations. Soil N availability appears to have had a greater effect on litter quality than did atmospheric CO 2 , although the treatments were additive, with highest concentrations of nonstructural carbohydrates and condensed tannins occurring under elevated CO 2 –low soil N. Rates of microbial respiration and the production of DOC were insensitive to differences in litter quality. In general, concentrations of litter constituents, except for starch, were highly correlated to those in live foliage, and the CNB/GDB hypotheses proved useful in predicting changes in litter quality. We conclude the chemical composition of sugar maple litter will change in the future in response to rising atmospheric CO 2 , and that soil N availability will exert a major control. It appears that microbial metabolism will not be directly affected by changes in litter quality, although conclusions regarding decomposition as a whole must consider the entire soil food web.