海岸濕地是地球上固碳效率最高的碳匯系統，其高碳匯能力有助於改善因人為活動導致的碳循環失衡及溫室效應。海岸濕地可藉由光合作用與潮汐作用將碳固定於濕地內：水生植物與底棲微藻行光合作用將無機碳轉換為有機碳；潮汐作用將有機碳沉降於濕地泥灘地或輸往外海作為海洋生物食源。本研究地點高美濕地是台灣西海岸典型海岸濕地，亦是保存較完整的雲林莞草鹹水草澤濕地，對於區域碳循環有重要的生態服務功能。本研究目的在量化高美濕地土壤碳存量時空變化與不同植被之影響，以期了解高美濕地底土存碳能力。於2011年8月至2012年5月的研究結果發現，高美濕地土壤碳存量之時空變化受到植被有無的影響，植被區碳含量明顯多於裸灘區，季節變化上則是有夏季最高、秋冬最低、春季回升的現象。在底土深度達30 cm的土體中，植被區的碳含量與土壤碳儲存能力速率皆優於裸灘區，草澤為0.44 ％、14.96 kg m-2 yr-1，海草床為0.25 ％、18.12 kg m-2 yr-1，裸灘為0.19 ％、-14.48 kg m-2 yr-1。高美濕地整體土壤碳儲存能力為113.88 kg m-2，儲存量為357.59 Gg。高美濕地底土以輸出有機碳為主，且輸出量多於植被生產量，其差額與潮汐及鄰近淡水輸入源的水體總碳或懸浮物質有關。若要更進一步探討高美濕地碳匯能力，需再進行潮汐與鄰近淡水輸入源的碳含量研究，以期整合底土、水體與生物（植被及底棲微藻）三大環節的高美濕地碳收支模式。有利於了解近代形成的鹹水草澤在碳循環上的角色與貢獻，及外來種與原生種的碳匯意義。 Coastal wetlands are considered as the most efficient carbon sequestration ecosystem on Earth, which can mitigate the aggravated greenhouse effect caused by human activities. Coastal wetlands fix carbon(C) in the system by photosynthesis and tidal movement. Hydrophytes and benthic microalgae transform inorganic C into organic C through photosynthesis; organic C may be deposited on the tidalflats and/or exported to the ocean as food source for marine organisms by tidal currents. Our research site, Kaomei wetland, is a typical coastal wetland in the western coast of Taiwan, where the tidal marsh plant Bolboschoenus planiculmis is distributed and provides important ecosystem services of C sequestration. To understand the ability of carbon sequestration in Kaomei wetland, this research aims at determining temporal and spatial changes in soil C stock and the influencing factors from August 2011 to May 2012. As the result showed, soil C stock was associated with vegetation, and the total carbon concentration(TC) in vegetated zone was higher than in sandflat. Soil C stock was also affected by seasonal change – higher in summer than the other seasons. In the top 30 cm of the soil bodies, vegetated zones had much better C stock capability than sandflats. Salt marsh had 0.44 %TC and 14.96 kg C m-2 yr-1; seagrass bed had 0.25 %TC and 18.12 kg m-2 yr-1; but sandflats only had 0.19 %TC and -14.48 kg m-2 yr-1. The average total soil carbon content in Kaomei wetland was 113.88 kg m-2 and the average carbon stock was 357.59 Gg. The sediment of Kaomei wetland released a lot of organic carbon that export amount was larger than vegetation production. For understanding of the C budget and flux in Kaomei Wetland, future works need to further analyze the TC of inflow water and C uptake rates by the major primary producers.