闽江河口湿地互花米草与芦苇光合特性及适应性研究

互花米草在闽江河口鳝鱼滩湿地中潮滩的入侵及快速扩张,已严重威胁到鳝鱼滩湿地的生物多样性及土著种沼泽植物生态系统的结构与功能。为了从植物光合速率的角度分析互花米草入侵及快速扩张的生理生态学机制,利用Li-6400便携式光合作用仪测定了互花米草与土著种芦苇的光合速率日进程及光合光响应曲线。结果表明,互花米草净光合速率的日均值与最大值均大于芦苇,互花米草可积累更多的光合作用产物,使其具有更快的生长速率和初级生产力。根据两种植物的光合光响应曲线可以看出,互花米草利用光合有效辐射的能力更强,显示出互花米草的高适应性。

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.