Liu De-yan, Song Chang-chun, Wang Li, Wang Li-li, Li Ying-chen
Northeast Institute of Geography and Agricultural Ecology, Chinese Academy of Sciences, Changchun 130012, China.
Huan Jing Ke Xue. 2008 Dec;29(12):3525-30.
By laboratory incubation experiment, under aerobic and submerged soil moisture conditions, we investigated the mineralization of soil organic carbon (SOC) and contents of dissolved organic carbon (DOC) with different nitrogen inputs in a freshwater marsh soil. The results showed that under aerobic condition, there were no significant effects on the mineralization of SOC and contents of DOC as the net nitrogen input was 1 mg x g(-1) (N1), however, they were significantly higher than control and N1 treatments when nitrogen input increased to 2 and 5 mg x g(-1) (N2, N3), and the amount of DOC was respectively 187.22% and 203.25% higher than control (250.62 mg x kg(-1)). Under submerged condition, all N treatments restrained the mineralization of SOC, and the content of DOC was respectively 88.34% (N1), 82.69% (N2) and 80.04% (N3) lower than control (642.52 mg x kg(-1)). There were significant positive correlations between the contents of DOC and the amounts of cumulative C by mineralization (R2 was 0.939 and 0.843, respectively), which suggested that the changes of DOC affected by N input might be one of the important reasons that arose the differences of SOC mineralization. The results also indicate that as the waterlogged environment disappeared in wetland, the supply of exogenous nitrogen might bring large loss of SOC through enhancing the mineralization of SOC and leaching of DOC.
通过实验室培养实验，在好氧和淹水土壤湿度条件下，我们研究了淡水沼泽土壤中不同氮输入情况下土壤有机碳（SOC）的矿化作用以及溶解有机碳（DOC）的含量。结果表明，在好氧条件下，当净氮输入为1 mg·g⁻¹（N1）时，对SOC矿化作用和DOC含量没有显著影响，然而，当氮输入增加到2和5 mg·g⁻¹（N2、N3）时，它们显著高于对照和N1处理，DOC含量分别比对照（250.62 mg·kg⁻¹）高187.22%和203.25%。在淹水条件下，所有氮处理均抑制了SOC的矿化作用，DOC含量分别比对照（642.52 mg·kg⁻¹）低88.34%（N1）、82.69%（N2）和80.04%（N3）。DOC含量与矿化累积碳量之间存在显著正相关（R²分别为0.939和0.843），这表明氮输入影响DOC的变化可能是导致SOC矿化差异的重要原因之一。结果还表明，随着湿地淹水环境的消失，外源氮的供应可能通过增强SOC的矿化作用和DOC的淋溶导致SOC大量损失。
