闽江河口潮汐沼泽湿地CO_2排放通量特征

以闽江河口区面积最大的鳝鱼滩湿地分布的3种植物沼泽湿地：土著种咸草（Cyperus malaccensis Lam.var.brevifolius Bocklr.）沼泽湿地、芦苇（Phragmites australis）沼泽湿地及外来入侵种互花米草（Spartina alterniflora Loisel.）沼泽湿地...

Carbon dioxide emission from tidal marshes in the Min River Estuary

CO₂ emission to the atmosphere and its seasonal variation in 2009 were studied using an enclosed static chamber technique from three tidal marshes dominated respectively by two native species of Cyperus malaccensis var.bervifolius and Phragmites australis (common reed), and an alien invasive species of Spartina alterniflora in the Shanyutan Wetland in the Min River Estuary, southeast China. Measurements were taken during three tidal stages (exposed-before flood, submerged-flooding and ebbing process, and exposed-after ebb). There were considerable monthly variations with greater CO₂ emissions before flood in some months, whereas at other months greater CO₂ emission after ebb. The monthly averaged CO₂ emissions during three tidal stages from the P. australis stand were highest, which were (563.7±119.8), (230.3±54.2) and (506.2±83.8) mg·m^-2·h^-1, respectively. Tidal inundation had an obvious affect on CO₂ emission. CO₂ emissions from these three plant stands were all significantly lower during the period of tidal inundation (submerged-flooding and ebbing process) than that at the exposed-stage (before flood and after ebb)(p<0.05). However, there was no significant difference on CO₂ emissions observed between before flood stage and after ebb stage. CO₂ emissions from the P. australis stand and the C. malaccensis stand had a significant positive correlation with soil and air temperature.