Specific absorption coefficient and the phytoplankton package effect in Lake Taihu, China
Specific absorption coefficient and the phytoplankton package effect in Lake Taihu, China
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DOI：
10.1007/s10750-008-9579-6
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发表时间：
2009-02
期刊：
影响因子：
2.6
通讯作者：
C. Le;Yunmei Li;Y. Zha;D. Sun
中科院分区：
文献类型：
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作者：
C. Le;Yunmei Li;Y. Zha;D. Sun
为了解太湖浮游植物的吸收和比吸收系数的变化，于2007年11月8-22日采集了太湖57个水样。考察了包装效应和辅助颜料对吸收光谱的影响。用质量过滤技术测定浮游植物的吸收，用“热无水乙醇”法测定总胆红素浓度。结果浮游植物的吸收和TChl-a的比吸收系数有显著差异。浮游植物在675 nm处的吸收系数与TChl浓度高度相关，而在440 nm处的吸收系数与TChl浓度的相关性较小，主要原因是包装效应和辅助色素的影响。Aph*(λ)与Tchl浓度呈负相关。通过将APH*(λ)归一化为APH*(440)，确定了四种类型的吸收光谱。APH*(λ)的变化主要受辅助色素和包装效应的影响，在675 nm处的影响范围为83.2%~28%，平均为65.3%。同时，APH*(440)与APH*(675)的比值变化范围很大，说明副色素与TChl浓度的比值变化范围很大。这些研究结果对基于生物光学模型估算太湖水体中的叶绿素浓度、遥感估算初级生产力和制定进一步的太湖生态修复措施具有重要意义。
In order to investigate variations of absorption and total chlorophyll-a(TChl-a)-specific absorption coefficient of phytoplankton in Lake Taihu, 57 water samples obtained from Lake Taihu during November 8–22, 2007 were used in this study. Package effect and accessory pigments’ influences on the absorption spectra were also examined. Phytoplankton absorption was measured by quality filter technical, and TChl-aconcentration was measured by “hot ethanol” method. Results yielded significant variations in phytoplankton absorption and TChl-a-specific absorption coefficient. Phytoplankton absorption coefficient at 675 nm is highly correlated to TChl-aconcentration, while absorption at 440 nm is less correlated to TChl-aconcentration because of great package effect and accessory pigments’ influence. There was an inverse relationship betweenaph*(λ) and TChl-aconcentration. Four types of absorption spectra are identified by normalizingaph*(λ) toaph*(440). Theaph*(λ) variation is mainly due to accessory pigments and package effect, whose influence at 675 nm ranges from 83.2% to 28%, with an average of 65.3%. Meanwhile, the wide varying ratio ofaph*(440) toaph*(675) indicates a large variation range in the ratio of accessory pigment to TChl-aconcentration. Those findings are significant to estimate Chl-aconcentration based on bio-optical model, estimate primary production from remote sensing, and plan further ecological restoration measures for Lake Taihu.