盐水入侵及有机碳输入对河口淡水沼泽CH4、 N2O通量影响的短时效应

摘要

为了探究盐水入侵及外源有机碳输入对河口潮汐淡水沼泽湿地生态系统甲烷( CH4)和氧化亚氮( N2 O)通量的影响，运用中型实验生态系模拟法，通过添加人造海水和醋酸盐，结合气相色谱测定，对闽江河口短叶茳芏( Cyperus malaccensis )潮汐淡水沼泽湿地生态系统CH4和N2 O通量进行测定与分析。结果表明：1)盐分输入在短时内(24 h )显著抑制湿地CH4排放通量(P<0．05)，有机碳输入显著促进CH4排放通量(P<0．05)，盐水入侵耦合有机碳输入对CH4排放无显著影响。2)盐分输入、有机碳输入及两者的耦合作用在短时内(24 h)对湿地N2 O通量无显著影响。3)4种处理形式综合作用下，湿地CH4排放通量与土壤电导率显著负相关(P<0．05)， N2O通量与土壤pH表现为显著正相关(P<0．05)，与土壤Eh显著负相关(P<0．05)。4)短时内各添加处理对CH4和N2O综合增温潜势无显著影响。%According to the mesocosm simulated experiments method, by adding artificial seawater and acetate, combined with gas chromatography determination, we explored short-term effects of salt water intrusion and exogenous organic carbon input on the methane ( CH4 ) and Nitrous Oxide ( N2 O) flux from the ecosystem of Cyperus malaccensis tidal freshwater marsh wetland in Min River estuary. Results show that : 1) the salt input significantly inhibited the CH4 emission flux in a short time (24 h) (P<0. 05), organic carbon input significantly promoted the CH4 emission flux (P<0. 05), the inputs of saltwater intrusion coupled organic carbon had no significant effect on the emission flux of CH4 . 2) The N2 O emission flux was not significantly changed by the inputs of the salt, organic carbon and saltwater intrusion coupled organic carbon in a short time (24 h). 3) The CH4 emission flux was significantly neg-ative correlation with soil conductivity (P<0. 05), the N2O emission flux as significantly positive corre-lation with soil pH, negative correlation with soil Eh (P<0. 05). 4) There was no significant effects on global warming potential of CH4 and N2 O emission under different treatments in a short time.