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Estimating the contribution of leaf litter decomposition to soil CO 2 efflux in a beech forest using 13 C‐depleted litter
Author(s) -
Ngao Jérôme,
Epron Daniel,
Brechet Claude,
Granier André
Publication year - 2005
Publication title -
global change biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.146
H-Index - 255
eISSN - 1365-2486
pISSN - 1354-1013
DOI - 10.1111/j.1365-2486.2004.01014.x
Subject(s) - beech , litter , fagus sylvatica , plant litter , soil respiration , soil water , environmental science , decomposition , soil carbon , chemistry , agronomy , zoology , botany , ecology , nutrient , biology , soil science
The contribution of leaf litter decomposition to total soil CO 2 efflux ( F L / F ) was evaluated in a beech ( Fagus sylvatica L.) forest in eastern France. The Keeling‐plot approach was applied to estimate the isotopic composition of respired soil CO 2 from soil covered with either control (−30.32‰) or 13 C‐depleted leaf litter (−49.96‰). The δ 13 C of respired soil CO 2 ranged from −25.50‰ to −22.60‰ and from −24.95‰ to −20.77‰, respectively, with depleted or control litter above the soil. The F L / F ratio was calculated by a single isotope linear mixing model based on mass conservation equations. It showed seasonal variations, increasing from 2.8% in early spring to about 11.4% in mid summer, and decreasing to 4.2% just after leaf fall. Between December 2001 and December 2002, cumulated F and F L reached 0.98 and 0.08 kg C m −2 , respectively. On an annual basis, decomposition of fresh leaf litter accounted for 8% of soil respiration and 80% of total C loss from fresh leaf litter. The other fraction of carbon loss during leaf litter decomposition that is assumed to have entered the soil organic matter pool (i.e. 20%) represents only 0.02 kg C m −2 .