Temperature sensitivity of soil respiration from the typical land-use types in the Sanjiang Plain, northeastern Heilongjiang Province

Temperature sensitivity of soil respiration of the samples from different land-use types in the Sanjiang Plain was studied using the laboratory incubation method. The results show that, at four different temperature conditions of 5 ℃, 15 ℃, 25 ℃ and 35 ℃, soil respiration rates of all the soil types increase with the increasing temperature. Under the same temperature condition, the three types of soils are in order of increasing respiration intensities of meadow soil-dry land < meadow soil- paddy field < bog soil- plantation. Both of the exponential model and the power model can be used to describe the relationship between soil respiration and temperature of the soils, which means that soil respiration intensity increases exponentially or as power function with the increasing temperature. The Q10 values of the three kinds of soils show a trend of decreasing with increasing temperature, which suggests that the temperature sensitivity of soil respiration is higher at the lower temperature. By the comparative incubation experiments on the pure soil without plant residues and the control group with plant residues, the authors found that soil respiration is greatly enhanced with additional plant residues, so the actual soil respiration in the field is higher than that measured in the laboratory in which plant residues are usually removed.