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Roots and fungi accelerate carbon and nitrogen cycling in forests exposed to elevated CO 2
Author(s) -
Phillips Richard P.,
Meier Ina C.,
Bernhardt Emily S.,
Grandy A. Stuart,
Wickings Kyle,
Finzi Adrien C.
Publication year - 2012
Publication title -
ecology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.852
H-Index - 265
eISSN - 1461-0248
pISSN - 1461-023X
DOI - 10.1111/j.1461-0248.2012.01827.x
Subject(s) - cycling , nitrogen cycle , microbial population biology , nitrogen , soil carbon , mineralization (soil science) , carbon cycle , carbon fibers , soil organic matter , environmental chemistry , organic matter , decomposition , nutrient cycle , agronomy , biology , microorganism , ecology , botany , chemistry , soil water , ecosystem , bacteria , forestry , materials science , organic chemistry , composite number , composite material , genetics , geography
A common finding in multiple CO 2 enrichment experiments in forests is the lack of soil carbon ( C ) accumulation owing to microbial priming of ‘old’ soil organic matter ( SOM ). However, soil C losses may also result from the accelerated turnover of ‘young’ microbial tissues that are rich in nitrogen ( N ) relative to bulk SOM . We measured root‐induced changes in soil C dynamics in a pine forest exposed to elevated CO 2 and N enrichment by combining stable isotope analyses, molecular characterisations of SOM and microbial assays. We find strong evidence that the accelerated turnover of root‐derived C under elevated CO 2 is sufficient in magnitude to offset increased belowground inputs. In addition, the C losses were associated with accelerated N cycling, suggesting that trees exposed to elevated CO 2 not only enhance N availability by stimulating microbial decomposition of SOM via priming but also increase the rate at which N cycles through microbial pools.