Fine root dynamics in species-rich calcareous meadows of the Swiss Jura under elevated atmospheric CO{sub 2}
- Universitaet Basel (Switzerland)
Minirhizotron fine-root observations tubes were inserted in the soil of lowland calcareous grassland communities of northwestern Switzerland to measure the effects of atmospheric carbon dioxide concentration on fine root productivity and mortality (or {open_quotes}turnover{close_quotes}). We tested the hypothesis that increased turnover would help explain the fate of the excess carbon taken up by these grassland ecosystems at elevated CO{sub 2} that are not accounted for by increased plant biomass. The direct observation of fine root populations allows us to determine whether carbon inputs to the soil via enhanced rhizodeposition are greater under elevated CO{sub 2}. One-square-meter plots containing similar undisturbed meadow communities are being exposed (since March 1994) to atmospheres containing either ambient or 600 {mu}l CO{sub 2} 1{sup -1} using open-top chambers (eight plots per CO{sub 2} treatment). Preliminary data from the early part of the first growing season under CO{sub 2} treatment indicate that 5 to 20% more fine root mortality occurred in plots treated with elevated CO{sub 2}. These results suggest a greater carbon deposition to the soil compartment under elevated CO{sub 2} and explain the fate of at least some of the excess carbon fixed by these ecosystems relative to those exposed to ambient CO{sub 2}.
- OSTI ID:
- 95740
- Report Number(s):
- CONF-9507129-; ISSN 0012-9623; TRN: 95:004728-0005
- Journal Information:
- Bulletin of the Ecological Society of America, Vol. 76, Issue 2; Conference: 80. anniversary of the transdisciplinary nature of ecology, Snowbird, UT (United States), 30 Jul - 3 Aug 1995; Other Information: PBD: Jun 1995
- Country of Publication:
- United States
- Language:
- English
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