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Demographic changes in a calcareous grassland community under elevated CO{sub 2}

Journal Article · · Bulletin of the Ecological Society of America
OSTI ID:95876

Increasing atmospheric CO{sub 2} has the potential to change community composition and canopy structure. To test this hypothesis a long-term CO{sub 2} field experiment using open top chambers with ambient and elevated (600ml 1{sup -1}) CO{sub 2} was started in March 1994 in a calcareous grassland in the Swiss Jura mountains. Potential changes in plant cover in the first year of exposure were non-destructively assessed by point intercept measurements (n=8). Biomass was harvested in June. After 3 months of exposure, no differences in either cover or biomass between the treatments were observed. Point intercept measurements showed that the fraction of legumes in the sward was 16% lower under elevated CO{sub 2} and the only group that showed a positive response on CO{sub 2} was Carex spp. (+30%). Measurements of leaf development on Carex flacca showed an increase in leaf growth by 32% and in final leaf length by 22% in elevated CO{sub 2}. The biomass harvest showed similar trends for Carex and legumes biomass. These findings show that a change in atmospheric CO{sub 2} concentrations may lead to changes in species composition of a grassland community within relatively short time and that legumes do not seem to profit from elevated CO{sub 2} in this community as has generally been hypothesized.

OSTI ID:
95876
Report Number(s):
CONF-9507129--
Journal Information:
Bulletin of the Ecological Society of America, Journal Name: Bulletin of the Ecological Society of America Journal Issue: 2 Vol. 76; ISSN BECLAG; ISSN 0012-9623
Country of Publication:
United States
Language:
English