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东北地区是我国乃至全球对气候变化响应比较敏感的地区之一,土壤呼吸的温度敏感性对该地区农田生态系统碳循环与全球气候变化之间的反馈关系产生重要影响。本文采用红外辐射加热装置模拟土壤增温,研究了模拟增温对黑土农田大豆生长季土壤呼吸作用的影响。结果表明:1)模拟增温导致10 cm深处平均土壤温度显著提高了2.76℃。2)在大豆生长期间,土壤呼吸速率呈现显著的季节性变化规律,峰值出现在开花-结荚期。3)模拟增温后,黑土农田大豆生长季的土壤呼吸速率(3.20μmol·m~(-2)·s~(-1))略高于对照处理(2.96μmol·m~(-2)·s~(-1)),但差异未达到显著水平,并且增温未显著影响大豆各生育期的土壤呼吸水平。4)虽然增温处理显著增加了大豆地上生物量,但未显著改变根系生物量和土壤含水量,说明根系生物量和土壤含水量是调控土壤呼吸对增温响应的主导因子。连续两年增温对黑土农田大豆生长季土壤呼吸没有明显的促进作用,表明土壤呼吸作用对增温环境产生了一定的适应性。
Northeast China is one of the most sensitive areas in China and even in the world in response to climate change. The temperature sensitivity of soil respiration has a significant impact on the feedback relationship between the carbon cycle of farmland ecosystem and global climate change. In this paper, the infrared radiation heating device was used to simulate soil warming, and the effects of simulated warming on soil respiration in the growing season of soybean in the black soil were studied. The results showed that: 1) The average soil temperature at 10 cm depth increased by 2.76 ℃ with simulated warming. 2) During the period of soybean growth, the soil respiration rate showed a significant seasonal variation and the peak appeared in the flowering-podding stage. 3) After simulated warming, the soil respiration rate (3.20μmol · m -2 · s -1) in the black soil cropland growing season was slightly higher than that in the control treatment (2.96μmol · m -2 · · s ~ (-1)), but the difference did not reach significant level, and warming did not significantly affect the soil respiration of soybean in different growth stages. 4) Although warming significantly increased aboveground biomass of soybean, it did not change the root biomass and soil water content significantly, indicating that root biomass and soil water content are the dominant factors that regulate the response of soil respiration to warming. The two consecutive years of warming did not significantly promote the soil respiration in the growing season of black soil farmland, indicating that the respiration of soil had some adaptability to the warming environment.