摘要:采集鄱阳湖沉水植物区0-10 cm和10-30 cm土壤样品，通过设置2个温度（18℃和28℃）和2个水分（淹水2 cm和土柱取出水面后的实际土壤水分含量）处理组合，进行持续2年的甲烷（CH₄）排放室内培养实验，以探讨不同深度土壤CH₄排放对温度、水分变化的响应差异，以及温度、水分和土层对湿地土壤CH₄排放的交互影响。结果表明：0-10 cm和10-30 cm土壤CH₄排放速率变化范围分别为0.01-3.63 μgCH₄-C kg^-1d^-1、0.02-1.99 μgCH₄-C kg^-1d^-1；均值分别为0.72和0.15 μgCH₄-C kg^-1d^-1。温度、水分和土层3因素及其交互作用均对土壤CH₄排放有显著影响（P<0.01），且土层的影响最大。两水分处理下的CH₄排放对温度变化的敏感性均表现为0-10 cm（Q₁₀为1.78、3.26）高于10-30 cm土层（Q₁₀为1.04、1.08）。CH₄平均排放速率及累计排放量均表现为0-10 cm显著高于10-30 cm土层，且培养前期高于培养后期，显示基质有效性对土壤CH₄排放的重要影响。



Abstract:This study analyzes the different response of CH₄ emissions from two soil depths to temperature and moisture changes, as well as the interactive effects of temperature, moisture and soil layer. To accomplish this objective, soils in the submerged plant zones of Poyang Lake were sampled at depths of 0-10 cm and 10-30 cm. Subsequently, the soil samples were incubated for two years at two distinct temperatures (18℃ vs 28℃) and at two moisture treatments (the initial soil moisture during initial soil sampling vs the moisture at 2 cm water depth).The results showed that the soil CH₄ emissions varied from 0.01 to 3.63 μgCH₄-C kg^-1 d^-1 for the 0-10 cm depth samples, and 0.02 to 1.99 μgCH₄-C kg^-1 d^-1 for the 10-30 cm depth samples, respectively. Temperature, moisture, soil layer and their interactions all had significant effects on soil CH₄ emissions (P<0.01), though the soil layer had the maximum impact. It was observed that the temperature sensitivity of soil CH₄ emissions from the 0-10 cm depth samples was higher than that of the 10-30 cm depth sample for both of the moisture treatments. Both mean and cumulative soil CH₄ emissions from the 0-10 cm depth samples were significantly higher than the 10-30 cm depth samples. In addition, soil CH₄ emissions in the early incubation period were higher than the later period, suggesting that the substrate availability can play a substantial role in soil CH₄ emissions in wetlands.





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