Monthly Change Of Soil Respiration And Temperature Sensitivity Research In Typical Poplar Protection Forests In Coastal Area Of Northern Jiangsu Province

To understand soil respiration and its sensitivity to temperature is an important basis for accurately evaluating the response of terrestrial carbon cycles to future climatic change. There is a large area of shelter forests in the long silting coast in China. In this paper, soil respiration of typical shelter forestland—Poplar/ Metasequoia Glyptostroboides plantations were investigated in a silting coastal area of northern Jiangsu province. Soil CO₂ flux was measured with the static alkali absorption method. Results showed that between 2008.2 and 2009.1 the soil respiration rate varied from 2.9²1.7gCO₂m^-2h^-1, higher in Apr. - Sep. and lower in winter. The seasonal change of the soil respiration rate is different due to the tree species and the age of the forest. The respiration rate also got lower in plantations with clear cut and root-cut treatment. Root-cut treatment in the forest stands had a significant influence to the carbon fluxes. The CO₂ flux showed significant correlation with the organic carbon content of the forest soil.Temperature was the major factor controlling soil respiration. And the soil water content was not significantly correlated with soil respiration rate and it was not a key factor to soil respiration. The temperature sensitivity of soil respiration(Q₁₀) had the highest significant correlation with the soil temperature of 10cm depth, Q₁₀ value is higher in poplar plantation, but in plantations of Metasequoia Glyptostroboides, the trend above turned to be opposite.