Abstract:In order to understand the dynamic change of soil respiration rate and it’s response to meteorological factors, soil respiration rate of Eucalyptus urophylla×E. grandis plantation in Leizhou Peninsula was measured by using LI-8100A Soil carbon flux automatic measurement system. The results indicated that soil respiration rate of E. urophylla×E. grandis plantation changed distinctly from March 2016 to February 2017, showing single peak curve with the maximum at May, 2016 and minimum at February, 2017, respectively. The mean soil respiration rate was (2.34±0.70) μmol m-2s-1. According to the correlation coefficient, the influencing factors on soil respiration rate was ordered as soil temperature > air temperature > atmospheric pressure > photosynthetical active radiation > vapor pressure deficit > soil moisture. Furthermore, the principal component analysis showed that the variation of heat energy caused by temperature and photosynthetical active radiation and that of moisture caused by soil moisture were the main effect factors on soil respiration rate. The meteorological factors model was reliable due to 94.0% variation of soil respiration rate can be explained by regression analysis. The cumulative annual CO2 flux of soil surface in E. urophylla×E. grandis plantation was estimated as 893.31 g C m-2a-1. The temporal variation of soil respiration could be fully explained by coupling effect of meteorological factors.
