The Characteristic Of Soil Respiration Of Different Vegetation Communities In Rainy Area Of West China

Soil respiration is an important process in soil ecosystem, and it is the major approach by which the carbon in the soil fluxes into the atomsphere, and thus it is connected with global climate change. In order to reveal the variation of soil respiration and characteristics of carbon emission on different vegetation communities in Rainy Area of West China, Static closed chamber-alkali absorption technique was used to measure soil respiration rate and their regulating factors of seven vegetation types in boss Hill Botanic Garden of Sichuan Agricultural University from Jan2011to Dec2011. The Purpose is to study soil respiration in time and space and the relationship between soil temperature, soil water content,soil microbial biomass carbon and soil respiration.The results were as follows:(1) The seasonal fluctuations of soil respiration rates were apparent absolutely by different types with each other. The maximum values appeared in summer, and the minimum values were in winter. Annual average soil respiration rate of Farmland, Cinnamomum campHora, Orchard, Mixed forest, Neosino calamus affinis,Metasequoia glyptostroboides and Cryptomeria fortune-i Hooibrenk were332.67、296.8、233.78、320.74、242.46、267.74and266.50mgCO2m-2h-1, Seasonal variation ranges were56.61-642.28、67.53-537.827、57.91-579.75、51.06-622.11、45.27-531.03、55.46-515.59and43.07-570.76mgCO2m-2h-1, amplitude of variation were176.05%、162.38%、223.22%、178.04%、200.35%、171.86%and198.01%.(2) The relationship of soil temperature with soil respiration between seven different vegetation communities is significant function, soil temperature can account for73%-90%of soil respiration, Q10values of soil respiration rate range from2.43to3.36. Q10value of Ci Zhulin at the same soil depth is greater than that of other vegetation types, which shows that soil respiration of this type is more sensitive to temperature changes(3) Soil moisture linear model with seven different vegetation communities in soil respiration rate did not reach the level of significance (p>0.05), on the contrary, which shows that the soil moisture is not the key factors of soil respiration in the study area.(4) Correlation of Cinnamomum campHora, Orchard, Mixed forest, Neosino calamus affinis,Metasequoia glyptostroboides and Cryptomeria fortunei Hooibrenk between soil respiration and soil microbial biomass carbon is significant, indicating that the microbial biomass carbon is the chief factor in affecting the seasonal variation of soil respiration. Correlation between Soil respiration and microbial biomass carbon of farmland was not significant, which shows that soil microbial biomass carbon of farmland is not the main factor in affecting the seasonal variation of soil respiration.