基于感光色素吸收信号的太湖藻类识别

IDENTIFICATION OF ALGAE USING PHOTOSENSITIVE PIGMENT ABSORPTION SIGNALS IN TAIHU LAKE

铜绿微囊藻和斜生栅藻是太湖"水华"的主要藻种,基于室内纯铜绿微囊藻、斜生栅藻组成色素的吸收系数,通过四阶微分、标准化系数等方法对太湖水体浮游植物中铜绿微囊藻和斜生栅藻进行识别,并确定其组成比例。结果表明,纯藻组成色素的吸收系数应用于其在太湖水体浮游植物中比例的确定和识别中,能够全面考虑辅助色素的识别作用,较好地避免非色素物质吸收信号的干扰,具有较好的识别效果。太湖水体浮游色素中铜绿微囊藻比例最高,斜生栅藻次之,由夏季向冬季过度中,铜绿微囊藻比例不断减小,斜生栅藻的比例逐渐升高,但铜绿微囊藻比例仍略高于斜生栅藻;铜绿微囊藻的区域分布差异性较小,但时间差异性相对较大,而斜生栅藻恰恰相反,空间分布差异性较大而时间分布差异性较小。

Microcystis aentginosa and Scenedesmus obliquus are the main part of algae blooms in Lake Taihu. For the purpose of identify the type and percentage of algae in algae blooms, thrice courses experiment were carried out on 16^th Aug., 23^th Oct., 2006 and 12^th Nov., 2007, additionally, photosensitive pigment absorption signals of pure Microcystis aentginosa and Scenedesmus obliquus were measured in the laboratory. The photosensitive pigments of water samples were identified by the methods of Fourth-Derivative and standardization coefficient. Then the percentage of Microcystis aentginosa and Scenedesmus obliquus in the Taihu Lake were estimated through the match-up method of absorption signals. The results indicated that photosensitive pigment absorption signals of pure algae could be well used in the al-gae identification; it made a full consideration to the effect of Auxiliary pigment in identification, and gave a better method to avoid the interference of non-pigment material absorption signal. Microcystis aentginosa had the highest percentage in the wild phytoplankton population, which followed by Scenedesmus obliquus. The proportion of Micro-cystis aeruginosa decreased from summer to winter, while Scenedesmus obliquus increased gradually, but the percent-age of Microcystis aeruginosa still slightly higher than that of Scenedesmus obliquus. The spatial variation of Microcys-tis aeruginosa is very small, but the temporal difference is huge, on the contrary, Scenedesmus obliquus has large spatial variation and small temporal variation.