Abstract: Abstract: 〖WT5BZ〗
By using static chamber and gas chromatography, the seasonal and interannual variations of CO₂ fluxes in the Carex schmidtii marsh and Betula ovalifolia-C. schmidtii shrub swamp ecosystems in Xiaoxing’an Mountains were studied in the growth seasons of 2007 and 2008, with the relationships between these variations and environmental factors analyzed. The annual total CO₂emissions from C. schmidtii marsh and B. ovalifolia-C. schmidtii shrub swamp were 17841.78 and 20130.56 kg·hm^-2 in 2007, and 16331.78 and 18294.24 kg·hm^-2 in 2008, respectively. There was an obvious seasonal variation in the CO₂  emissions during the whole observation period, with the peak in summer (487.89 and 549.62 mg·CO₂ m^-2·h^-1 in 2007, and 391.53 and 438.31 mg·CO₂  m^-2·h^-1  in 2008 for the marsh and shrub swamp, respectively). A significant difference in the CO₂ emissions was observed between the two ecosystems, but no difference was found between years. Temperature was the key factor affecting the seasonal and interannual variations of CO₂  fluxes, and there existed significant positive relationships between the CO₂  fluxes and the air temperature, temperature inside the chamber, and soil temperature at 0-20 cm depth. Ground water level was also the main factor controlling the CO₂ emissions.

Key words: Wild Chinese alligator, Habitat, Vegetation, Diversity