Fluxes of CO2, N2O and CH4 from a typical temperate grassland in Inner Mongolia and its daily variation
Tóm tắt
Using a dark enclosed chamber technique, the fluxes of CO2, N2O and CH4 from nature and disturbed grassland were measured on the spot in Inner Mongolian Temperate Grassland along the annual rainfall gradient section ranging from 450 to 200 mm. The results showed that the measured mean fluxes of CO2, N2O and CH4 were (1 180.4 ± 308.7), (0.010 ± 0.004) and (−0.039 ± 0.016) mg · m−2/h, respectively. The decrease of the fluxes of CO2, N2O and CH4 follows with that of annual rainfall gradient in the measurement area. Human activities, such as grazing and reclamation are also critical factors to affect the fluxes of these gases from grassland. Daily continuous measurement of CO2, N2O and CH4 fluxes showed a strong diurnal variation with higher emission in the daytime. A good relationship between the fluxes of CO2, N2O, CH4 and temperature was exposed in this study.
Tài liệu tham khảo
Castro, M. S., Stedudler, P. A., Mellio, J. M., Factors controlling atmospheric methane consumption by temperate forest soils, Global Biogeochemistry Cycles, 1995, 9: 1.
Raich, J. W., Potter, C., S., Global patterns of carbon dioxide emissions from soil, Global Boigeochemistry Cycles, 1995, 9: 23.
Rodhn, H. A., A comparison of the contribution of various gases to the greenhouse effect, Science, 1990, 248: 1217.
Lloyd, D., Microbial processes and the cycling of atmospheric trace gases, Trends in Ecology and Evolution, 1995, 10: 476.
Crutzen, P. J., The influence of nitrogen oxide on the atmospheric ozone content, Quart. J. Roy. Meterol. Soc., 1970, 96: 7311.
Sanhueza, E., Dong, Y., Scharffe, D. et al., Carbon monoxide uptake by temperate forest soils: the effects of leaves and humus layers, Tellus, 1998, 50(B): 51.
Zhang, X. S., Gao, Q., Yang, D. A. et al., A gradient analysis and prediction on the Northeast China Transect (NECT) for global change study, Acta Botanic Sinica (in Chinese), 1997, 39(9): 785.
Dong, Y., Scharffe, D., Lobert, J. et al., Fluxes of CO2, CH4 and N2O from a temperate forest soils: the effect of leaves and humus layers, Tellus, 1998, 50(B): 243.
Bouwman, A. F., van der Hoek, K. W., Olivier, J. G. J., Uncertainties in the global source distribution of nitrous oxide, J. Geophys. Res., 1995, 100: 2785.
Velthof, G. L., Jarvis, A., Stein, A. et al., Spatial variability of nitrous oxide fluxes in mown and grazed grasslands on a poorly drained clay soil, Soil Biol. Biochem., 1996, 28(9): 1215.
Yamulki, S., Harrison, R. M., Goulding, K. W. T. et al., N2O, NO and NO2 fluxes from a grassland: effect of soil pH, Soil Biol. Biochem., 1997, 29(8): 1199.
De Klein, C. A. M., van Logtestijn, R. S. P., Denitrification in grassland soils in the Netherlands in relation to irrigation, N-application rate, soil water content and soil temperature, Soil Biol. Biochem., 1996, 28(2): 231.