Responses of soil enzymes to long-term CO₂ enrichment in forest ecosystems of Changbai Mountains

Abstract

A study was conducted to determine the responses of soil enzymes (invertase, polyphenol oxidase, catalase, and dehydrogenase) to long-term CO₂ enrichment at the Research Station of Changbai Mountain Forest Ecosystems, Chinese Academy of Sciences (42°24′N, 128°28′E; 738 m in elevation) in the northeast China during 1999–2006. Three treatments of the CO₂ enrichment, designed as 500 μmol·mol⁻¹ CO₂ open-top chamber (OTC), ambient control chamber and unchambered field (approx. 370 μmol·mol⁻¹CO₂), were conducted with Pinus koraiensis and Pinus sylvestriformis tree species. Soil sampling was made and analyzed separately in spring, summer and autumn in 2006 after the soil enzymes were exposed to elevated CO₂ concentration (500 μmol·mol⁻¹) for eight growing seasons. Results showed that, at elevated CO₂ concentration (500 μmol·mol⁻¹), the activities of invertase (except for the summer samples of P. koraiensis) presented a remarkable decline in all growing seasons, while the activities of dehydrogenase had an increase but only part of the results was remarkable; the activities of polyphenol oxidase in P. sylvestriformis rhizosphere showed a remarkable decrease; the catalase activities increased in spring, while in turn were decline in other seasons. This study also revealed that the soil enzyme activities are significantly correlated with the tree species under the CO₂ enhancement.

Keywords

CO₂ concentration / CO₂ enrichment / Soil enzymes / Invertase / Dehydrogenase / Catalase / Polyphenol oxidase

References

[1] Bazzaz F.A. The response of natural ecosystems to the rising global CO₂ levels Annual Review of Ecology and Systematics, 1990, 21: 167-196.

[2] Dhillion S.S., Roy J., Abrams M. Assessing the impact of elevated CO₂ on soil microbial activity in a Mediterranean model ecosystem Plant and Soil, 1996, 187: 333-342.

[3] Hirschel G., KÖrner C., Arnone J.A. III Will rising atmospheric CO₂ affect leaf litter quality and in situ decomposition rates in native plant communities? Oecologia, 1997, 110: 387-392.

[4] Hu S., Firestone M.K., Chapin F.S. III Soil microbial feedbacks to atmospheric CO₂ enrichment Trends in Ecology and Evolution, 1999, 14: 433-437.

[5] Jia X., Han S., Zhou Y. Soil biochemical characters of Pinus koraiensis and Pinus sylvestriformis plantations under different elevated CO₂ concentration Chinese Journal of Applied Ecology, 2004, 15(10): 1842-1846.

[6] Kandeler E., Gerber H. Short-term assay of soil urease activity using colorimetric determination of ammonium Biology and Fertility of Soils, 1988, 6: 68-72.

[7] Kandeler E., Tscherko D., Bardgett R.D. et al. The response of soil microorganisms and roots to elevated CO₂ and temperature in a terrestrial model ecosystem Plant and Soil, 1998, 202: 251-262.

[8] Kang H., Freeman C., Ashenden T.W. Effects of elevated CO₂ on fen peat biogeochemistry The Science of the Total Environment, 2001, 279(1–3): 45-50.

[9] Killham K. Soil ecology, 1994 Cambridge: Cambridge University Press

[10] Körner C. Biosphere responses to CO₂ enrichment Ecological Applications, 2000, 10: 1590-1619.

[11] Körner C., Arnone J.A. III Responses to elevated carbon dioxide in artificial tropical ecosystems Science, 1992, 257: 1672-1675.

[12] Lamborg M.R., Hardy R.W.F., Paul E.A. Lemon E.R. Microbial effects CO₂ and Plants, the response of plants to rising levels of atmospheric carbon dioxide, 1983 Boulder, CO: Westview Press 131-176.

[13] Niklaus P.A., Alphei J., Ebersberger D. et al. Six years of in situ CO₂ enrichment evoke changes in soil structure and soil biota of nutrient poor grassland Global Change Biology, 2003, 9: 585-600.

[14] Norby R.J., Cotrufo M.F., Ineson P. et al. Elevated CO₂, litter chemistry, and decomposition: a synthesis Oecologia, 2001, 127: 153-165.

[15] Paul E.A., Clark F.E. Soil microbiology and biochemistry, 1996 San Diego: Academic Press, CA 340

[16] Rogers H.H., Runion G.B., Krupa S.V. Plant responses to atmospheric CO₂ enrichment with emphasis on roots and the rhizosphere Environmental Pollution, 1994, 83: 155-189.

[17] Ross D.J., Saggar S., Tate K.R. et al. Elevated CO₂ effects on carbon and nitrogen cycling in grass/clover turves of a Psammaquent soil Plant and Soil, 1996, 182: 185-198.

[18] Ross D.J., Tate K.R., Newton P.C.D. Elevated CO₂ and temperature effects on soil carbon and nitrogen cycling in ryegrass/ white clover turves of an Endoaquept soil Plant and Soil, 1995, 176: 37-49.

[19] Zak D.R., Pregitzer K.S., King J.S. et al. Elevated atmospheric CO₂ fine roots and the response of soil microorganisms: a review and hypothesis New Phytologist, 2000, 147: 201-222.

[20] Zhang L., Zhang Y., Wu Z. et al. Response of soil saccharidase activities to free air carbon dioxide enrichment(FACE) under rice-wheat rotation Chinase Journal of Applied Ecology, 2004, 15(6): 1019-1024.