The Measurement of Seagrass Photosynthesis Using PAM Fluorometry - Absorptance factors

To measure the photosynthetic rate of seagrasses using a Diving-PAM, it is first necessary to determine how much of the light reaching the leaves is absorbed and used in photosynthesis. The absorptance factors of each seagrass species are then used to determine the electron transport rates (ETR) and subsequently the photosynthetic rate. Hence this study determines absorptance factors for Posidonia sinuosa, Posidonia australis and Halophila ovalis, taking into account transmittance, reflectance and non-photosynthetic absorptance of light by the leaves from leaves taken for Woodman Point, WA on 27 May 2004.

为使用潜水式脉冲振幅调制荧光仪（Diving-PAM）测定海草的光合速率，首先需明确到达叶片的光照有多少被吸收并用于光合作用。后续可通过各海草物种的吸收系数计算电子传递速率（electron transport rates, ETR），进而得出光合速率。因此，本研究针对2004年5月27日采自西澳大利亚州伍德曼点的海草叶片，综合考量叶片对光照的透射率、反射率以及非光合吸收，测定了波叶波喜多海草（Posidonia sinuosa）、澳大利亚波喜多海草（Posidonia australis）和圆叶喜盐草（Halophila ovalis）的吸收系数。