Fe(Ⅲ)对藻类生长及光谱特征的影响

Effects of Fe(Ⅲ) on the growth and spectral characteristics of algae

利用室内培养实验,研究不同Fe(Ⅲ)浓度处理下太湖藻类叶绿素含量、藻类反射光谱随时间的变化规律。通过导数光谱技术、"红边"光学参数(红边位置)对藻类光谱信息进行定量提取,并与藻类叶绿素含量、藻体Fe(Ⅲ)含量进行相关分析,建立了培养液Fe(Ⅲ)浓度-藻类叶绿素含量-藻类光谱的定量关系。结果表明:适宜的Fe(Ⅲ)浓度(18μmol·L-1)有利于藻类生长及叶绿素合成,过高Fe(Ⅲ)浓度(30μmol·L-1)在培养前期能促进藻类叶绿素的合成,但在培养后期会抑制藻类叶绿素的合成,缺铁(0μmol·L-1)使叶绿素的合成受到显著的抑制;不同Fe(Ⅲ)浓度下藻类光谱植被指数(SR705、ND705)、红边位置与藻类叶绿素含量的相关性显著(P<0.05)。

An indoor culture experiment was conducted to study the temporal change patterns of chlorophyll content and reflectance spectra of algae from Taihu Lake under different Fe（Ⅲ） supply. Derivative spectrophotometry and red edge optical parameter were employed to quantitatively extract the algal spectral data, and correlation analysis was made between the algal spectral data and algal chlorophyll and Fe（Ⅲ） contents. Based on these, the quantitative relationship of supplied Fe（Ⅲ） concentration – algal chlorophyll content – algal spectra was established. The results showed that supplying appropriate concentration （18 μmol·L-1） Fe（Ⅲ） was conducive to the algal growth and chlorophyll synthesis. High concentration （30 μmol·L-1） Fe（Ⅲ） promoted the synthesis of algae chlorophyll at the prophase of culture, but inhibited it at the anaphase. Fe-deficiency significantly inhibited the synthesis of chlorophyll. Under different Fe（Ⅲ） supply, there existed significant correlations （P〈0.05） between the vegetation indices SR705 and ND705, red edge position, and the chlorophyll content of algae.