闽江河口芦苇沼泽和短叶茳芏沼泽生态系统含碳温室气体的年收支

河口感潮沼泽是全球重要的蓝碳生态系统，具有很强的固碳能力。碳收支研究是量化生态系统碳源/汇过程及固碳规模的基础。本研究运用透明箱和不同遮光率布遮盖+红外气体分析仪/气相色谱相结合的方法，模拟不同光照条件，测定闽江河口鳝鱼滩半咸水芦苇沼泽和短叶茳芏沼泽的瞬时净生态系统二氧化碳（CO₂）交换量（net ecosystem exchange，NEE）、生态系统呼吸（ecosystem respiration，ER）以及甲烷（CH₄）排放通量，并通过对总光合吸收量（gross ecosystem exchange，GEE）与光合有效辐射的拟合以及ER与气温的拟合，外推2个沼泽生态系统CO₂气体在月、年尺度上的NEE和ER，评估其年固碳量。2个沼泽生态系统的NEE和ER均具有明显的季节变化，春夏秋季为大气中CO₂的汇，而冬季则转化为大气中CO₂的源，芦苇沼泽年尺度固碳能力显著高于短叶茳芏沼泽。芦苇沼泽与短叶茳芏沼泽CH₄排放通量差异不显著。综合考虑CH₄排放，闽江河口鳝鱼滩半咸水芦苇沼泽、短叶茳芏沼泽生态系统年固碳量分别为（5371.52±336.97） g CO₂-eq/m²和（2730.32±503.67） g CO₂-eq/m²。研究表明：闽江河口半咸水沼泽湿地在年尺度上是一个较强的碳汇，在缓解全球变暖方面发挥着重要的角色。

Annual carbon gases budgets for Phragmites australis marsh and Cyperus malaccensis marsh in the Minjiang River estuary

Coastal tidal marsh ecosystem is one of coastal blue carbon ecosystems in world, and has high carbon sequestration capacity per unit area. Measurement on carbon budgets at ecosystem scale is critical for revealing carbon source/sink process and carbon sequestration. However, at present data of simultaneous measurement of net ecosystem exchange of CO₂ (NEE) and methane (CH₄) flux, and further assessment on carbon budgets has been poorly reported. Using transparent static chamber and shading by different refractive rates cloth+CO₂/H₂O gas analyzer/gas chromatograph, we measured the NEE, ecosystem respiration (ER), and CH₄ flux in the brackish Phragmites australis marsh and the Cyperus malaccensis marsh in the Minjiang River estuary. We also fitted the relationship between gross ecosystem exchange (GEE) and photosynthetically active radiation (PAR), ER and air temperature, and then estimated the GEE, NEE, and ER at month and annual scales. Both the NEE and ER demonstrated distinctly seasonal variations. The two marsh ecosystems were atmospheric CO₂ sink in spring, summer, and autumn, however in winter they changed to atmospheric CO₂ sources. The carbon sequestration capacity of the P. australis marsh was significantly higher than that from the C. malaccensis marsh. The CH₄ flux from the P. australis marsh was not different from that from the C. malaccensis marsh. Simultaneously considering the CH₄ flux, we calculated the carbon sequestration capacity of the P. australis marsh and the C. malaccensis marsh at annual scale, which was (5371.52±336.97) g CO₂-eq/m² and (2730.32±503.67) g CO₂-eq/m², respectively. The results suggest that both brackish P. australis marsh and C. malaccensis marsh in the Minjiang River estuary are strong atmospheric carbon sink, and plays an important role in mitigating global warming.