| Title |
Effects of Elevated CO2 and Pb on the Microbial Community in the Rhizosphere of Pinus densiflora |
| Author |
Sunghyun Kim1, Sun Hwa Hong2, Kyungsook Cho2, Insook Lee3, Gayoung Yoo4, and Hojeong Kang1* |
| Address |
1School of Civil and Environmental Engineering, Yonsei University, Seoul 120-749, Republic of Korea, 2Department of Environmental Science and Engineering, Ewha Womans University, Seoul 120-750, Republic of Korea, 3Division of Ecoscience, Ewha Womans University, Seoul 120-750, Republic of Korea, 4Department of Environmental Science and Engineering, Kyung Hee University, Yongin 446-701, Republic of Korea |
| Bibliography |
Journal of Microbiology, 50(6),895-901, 2012,
|
| DOI |
|
| Key Words |
elevated CO2, Pinus densiflora, enzyme activities, lead contamination, microbial community |
| Abstract |
Rising levels of atmospheric CO2 may stimulate forest productivity in the future, resulting in increased carbon storage in terrestrial ecosystems. However, heavy metal contamination may interfere with this, though the response is not yet known. In this study, we investigated the effect of elevated CO2 and Pb contamination on microorganisms and decomposition in pine tree forest soil. Three-year old pine trees
(Pinus densiflora) were planted in Pb contaminated soils (500 mg/kg-soil) and uncontaminated soils and cultivated for three months in a growth chamber where the CO2 concentration was controlled at 380 or 760 mg/kg. Structures of the microbial community were comparatively analyzed in bulk and in rhizosphere soil samples using community-level physiological profiling (CLPP) and 16S rRNA gene PCRDGGE
(denaturing gradient gel electrophoresis). Additionally, microbial activity in rhizospheric soil, growth and the C/N ratio of the pine trees were measured. Elevated CO2 significantly increased microbial activities and diversity in Pb contaminated soils due to the increase in carbon sources, and this increase was more distinctive in rhizospheric soil than in bulk soils. In addition, increased plant growth and C/N ratios of pine needles at elevated CO2 resulted in an increase in cation exchange capacity (CEC) and dissolved organic carbon (DOC) of the rhizosphere in Pb contaminated soil. Taken together, these findings indicate that elevated CO2 levels and heavy metals can affect the soil carbon cycle by
changing the microbial community and plant metabolism. |
