A Comparison of Photosynthetic Characteristics and Adaptability Between Spartina alterniflora and Phragmites australis in Min River Estuary Wetland

In Min River Estuary wetland, Spartina alterniflora has rapidly diffused and encroached upon the local plants’ habitat. As an invasive plant, Spartina alterniflora has become a threat to the local ecosystem. Understanding how the invasive plant Spartina alterniflora encroached successfully and the physiological and ecological mechanisms is one of the current hot topics in invasion ecology. Li-6400 Portable Photosynthesis (LI-COR inc. USA) was used to measure the photosynthetic characteristics of Spartina alterniflora and indigenous plant Phragmites australis in October, 2010. The results showed that: Spartina alterniflora has a significantly higher net photosynthetic rate (Pn) in both mean and maximum values compared with the local plant Phragmites australis. It means that the ability of using light energy of Spartina alterniflora is stronger than Phragmites australis, allowing the invasive plant accumulate more photosynthesis products. The study also showed that Spartina alterniflora had a better adaptability to salt environment due to a mechanism of effective salt resistance.