藻类的光谱吸收特征及其混合藻吸收系数的分离

利用定量滤膜技术测定了实验室培养的聚球藻(Synechococcus 7942)、铜绿微囊藻(Microcystis aeruginosa)、斜生栅藻(Scenedesmusobliquus)、蛋白核小球藻(Chlorella pyrenoidosa)、直链硅藻的吸收光谱(Melosira granulate Var.angustissima),通过其标准化吸收谱,分析了同种藻不同生长时期的吸收谱特征,并比较分析了不同藻类的标准化吸收谱.结果表明,同一藻的标准化吸收光谱在不同生长时期基本恒定不变.色素组成及其比例的不同是引起藻类间吸收光谱变化的主要原因,同时也是大型浅水湖泊中浮游植物种群演替的原因之一.蓝藻光谱主要存在620nm左右的吸收峰,使得其在水体中较易获取生长所需的光能.直链硅藻在短波范围内稍强的吸收能力被非藻类颗粒物、黄质所弱化,而其在630nm的吸收峰较低,因而难以成为浅水湖泊中的优势种;绿藻在655nm处的吸收肩峰有利于其光能竞争.通过纯种藻的标准化吸收谱,较为成功地对混合藻的吸收谱进行了分离.

Spectral absorption characteristics of algae and discrimination of the absorption spectrum of mixed algae

The absorption spectra of Microcystis aeruginosa, Scenedesmus obliquus, Chlorella pyrenoidosa, Selenostrum capricornutum and Melosira granulate var angustissima were taken and compared to the counts obtained by the quantitative filter technique. The normalized absorption spectra were then compared. The normalized absorption spectra were seldom variational in different growth period. The species differences of pigment and the ratio among different pigment species account for the variance of absorption spectra and are also the primary reason for species succession of phytoplankton in waters. Cyanobacteria have a peak at 620 nm, which is propitious to compete for light. The short-wave advantage of Melosira granulate var angustissima was waken by the colored dissolved organic matter (CDOM) and non-algae particles and the absorption peak at 630 nm is not strong, which is why Melosira granulate var angustissim is less able to compete for light. For green algae, the absorption shoulder at 655 nm helps them compete for light. The spectral absorption of mixed algae was successfully partitioned from the normalized absorption spectrum. This research is relevant to research on the mechanisms of cyanobacteria blooms, species succession of phytoplankton in natural waters, and remote sensing for case 2 waters.