增温与倍增CO_2对滇池香蒲和水葱湿地土壤可溶性碳的影响

Effect of Warming and Doubling CO_2 on Soil DOC of Cattail and Scirpus Communities in Dianchi Lake

采用闭合式“人工控制气候模拟实验系统”,通过控制温度和CO_2浓度,研究香蒲群落和水葱群落湿地土壤可溶性有机碳（DOC）的变化规律。结果表明：增温和倍增CO_2浓度均可使湿地土壤DOC含量出现不同程度的增加,增温对湿地土壤可溶性有机碳含量影响最大。在0~15 cm土层内,单独增温或单独倍增CO_2处理,土壤DOC含量均高于增温＋倍增CO_2处理,说明在土壤表层,温度与CO_2的交互作用对土壤DOC产生具有一定的抑制作用。在15~30 cm土层内,土壤DOC含量大小为ET〉ETC〉EC〉CK。相同处理下,土壤DOC含量香蒲群落明显高于水葱群落,表明增温和倍增CO_2浓度均使土壤中DOC含量增加,与水葱群落相比,香蒲群落更利于土壤DOC含量的增加。

By using closed ＂artificial climate control simulation experiment system＂ to controlling temperature and CO2 concentration, this paper studied the DOC mutative law of wetland soil of cattail and scirpus communities. The results showed both warming and doubling CO2 concentration increased the DOC content of wetland soil at varying degrees , warming had the greatest influences on the DOC content of wetland soil. Within 0-15 cm soil layer, soil DOC concentration under warming or doubling CO2 concentrations were higher than that of combination of warming and doubled CO2 concentration, which indicated that the interaction of temperature and CO2 had antagonism on soil DOC in the soil surface, Within 15-30 cm soil layer, the content of soil DOC was in order of ET 〉 ETC 〉 EC 〉 CK. Under the same treatment, the content of soil DOC in cattail community was significantly higher than that of scirpus community, which indicated that both warming and doubling CO2 concentration could increase the content of soil DOC. Compared with scirpus community, cattail community was more conducive to increase the content of soil DOC.