Abstract
Changes in plant species diversity can result in synergistic increases in decomposition rates, while elevated atmospheric CO2 can slow the decomposition rates; yet it remains unclear how diversity and changes in atmospheric CO2 may interact to alter root decomposition. To investigate how elevated CO2 interacts with changes in root-litter diversity to alter decomposition rates, we conducted a 120-day laboratory incubation. Roots from three species (Trifolium repens, Lespedeza cuneata, and Festuca pratense) grown under ambient or elevated CO2 were incubated individually or in combination in soils that were exposed to ambient or elevated CO2 for five years. Our experiment resulted in two main findings: (1) Roots from T. repens and L. cuneata, both nitrogen (N) fixers, grown under elevated CO2 treatments had significantly slower decomposition rates than similar roots grown under ambient CO2 treatments; but the decomposition rate of F. pratense roots (a non-N-fixing species) was similar regardless of CO2 treatment. (2) Roots of the three species grown under ambient CO2 and decomposed in combination with each other had faster decomposition rates than when they were decomposed as single species. However, roots of the three species grown under elevated CO2 had similar decomposition rates when they were incubated alone or in combination with other species. These data suggest that if elevated CO2 reduces the root decomposition rate of even a few species in the community, it may slow root decomposition of the entire plant community.
Original language | English |
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Pages (from-to) | 2347-2354 |
Number of pages | 8 |
Journal | Soil Biology and Biochemistry |
Volume | 43 |
Issue number | 11 |
DOIs | |
State | Published - Nov 2011 |
Funding
We thank David Harris, Charles Garten Jr., and Joanne Childs for assisting with chemical analyses. Thanks to Paul Kardol for assisting with root harvesting. Richard Norby and Jake Weltzin were integral in establishing the OCCAM experiment and provided logistical support. Research was sponsored by the U.S. Department of Energy , Office of Science, Biological and Environmental Research Program , and work was conducted in collaboration with Oak Ridge National Laboratory, which is managed by UT-Battelle, LLC, for the U.S. Department of Energy.
Funders | Funder number |
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Biological and Environmental Research program | |
U.S. Department of Energy | |
Office of Science |
Keywords
- Carbon-13
- Decomposition
- Elevated CO2
- Litter quality
- Nitrogen mineralization
- Roots
- Species diversity