[Study on the distinguishing of root respiration from soil microbial respiration in a Leymus chinensis steppe in Inner Mongolia, China].

Root biomass exponential regression method was used to distinguish root respiration from soil microbial respiration in a Leymus Chinensis steppe in the Xilin River Basin of Inner Mongolia, China. The contribution of root respiration to soil respiration averaged (24 +/- 3)%, ranging from 13%-52%; while the contribution of microbial respiration to soil respiration averaged (76 +/- 3)%, ranging from 48%-87%. Correlation between soil respiration and root biomass was relatively unstable.

[Analysis of difference between ecosystem respirations of Leymus chinensis steppe and Stipa baicalensis steppe].

Static opaque chamber-chromatographic technique was applied to measure the ecosystem respirations of Leymus chinensis steppe and Stipa baicalensis steppe. The affecting factors of ecosystem respiration were analyzed. The difference between ecosystem respirations of the two grasslands was compared and the reasons resulting in the difference were analyzed.

Emission characteristics of carbon dioxide in the semiarid Stipa grandis steppe in Inner Mongolia, China.

Using the static opaque chamber method, the soil respiration rates (SR) were measured through the continuous experiments in situ in semiarid Stipa grandis steppe in Xilin River Basin of Inner Mongolia, China from June 2001 to June 2003, in parallel, the difference between the SR and the ecosystem respiration rates (TER) were compared. The results indicated that the seasonal variations of the SR and TER were obvious with higher emissions in growing season and a relatively low efflux level in non-growing season, furthermore, the negative effluxes were found in the observation site in winter; the annual CO2 efflux of total ecosystem ranged from 160.5 gC/(m2 x a) to 162.

[Analyses of the correlation between the fluxes of CO2 and the distribution of C & N in grassland soils].

Using static dark enclosed chamber technique, the emissions of CO2 from typical temperate grasslands such as Stipa baicalensis, Leymus chinensis, Stipa grandis and Stipa krylovii in Xilin River Basin of Inner Mongolia were measured. And the contents of organic carbon and total nitrogen in different soil layers were also studied to analyze the correlation between the emissions of CO2 and the contents of C & N. The results showed that the emissions of CO2 from the 4 grassland communities were significantly positively correlated with soil organic carbon and total nitrogen in different layers of grassland soils, and the correlation coefficients were almost all above 0.