Cisneros Dozal, L.M. , Trumbore, S. and Hanson, P.J. (2007) Effect of moisture on leaf litter decomposition and its contribution to soil respiration in a temperate forest. Journal of Geophysical Research, 112, G01013. (doi: 10.1029/2006JG000197)
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Abstract
The degree to which increased soil respiration rates following wetting is caused by plant (autotrophic) versus microbial (heterotrophic) processes, is still largely uninvestigated. Incubation studies suggest microbial processes play a role but it remains unclear whether there is a stimulation of the microbial population as a whole or an increase in the importance of specific substrates that become available with wetting of the soil. We took advantage of an ongoing manipulation of leaf litter <sup>14</sup>C contents at the Oak Ridge Reservation, Oak Ridge, Tennessee, to (1) determine the degree to which an increase in soil respiration rates that accompanied wetting of litter and soil, following a short period of drought, could be explained by heterotrophic contributions; and (2) investigate the potential causes of increased heterotrophic respiration in incubated litter and 0–5 cm mineral soil. The contribution of leaf litter decomposition increased from 6 ± 3 mg C m<sup>−2</sup> hr<sup>−1</sup> during a transient drought, to 63 ± 18 mg C m<sup>−2</sup> hr<sup>−1</sup> immediately after water addition, corresponding to an increase in the contribution to soil respiration from 5 ± 2% to 37 ± 8%. The increased relative contribution was sufficient to explain all of the observed increase in soil respiration for this one wetting event in the late growing season. Temperature (13°C versus 25°C) and moisture (dry versus field capacity) conditions did not change the relative contributions of different decomposition substrates in incubations, suggesting that more slowly cycling C has at least the same sensitivity to decomposition as faster cycling organic C at the temperature and moisture conditions studied.
Item Type: | Articles |
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Keywords: | leaf litter, radiocarbon, soil respiration, litter moisture |
Status: | Published |
Refereed: | Yes |
Glasgow Author(s) Enlighten ID: | Cisneros, Dr Malu |
Authors: | Cisneros Dozal, L.M., Trumbore, S., and Hanson, P.J. |
Subjects: | Q Science > Q Science (General) |
College/School: | College of Science and Engineering > Scottish Universities Environmental Research Centre |
Journal Name: | Journal of Geophysical Research |
Journal Abbr.: | J. Geophys. Res. |
Publisher: | American Geophysical Union (AGU) |
ISSN: | 0148-0227 |
Copyright Holders: | Copyright © 2007 AGU |
First Published: | First published inJournal of Geophysical Research 2007 112:G01013 |
Publisher Policy: | Reproduced in accordance with the copyright policy of the publisher |
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