Effects of Light Intensity on Chlorophyll Content and PhotosyntheticFluorescence of Litsea cubeba and Cassia floribunda

Experiments were conducted on open air and 65% shading on Litsea cubeba and Cassia floribunda seedlings in May 2015 anddetermination was implemented in September. The result demonstrated that content of chlorophyll a, chlorophyll b, chlorophyll (a+b) and carotenoidof L. cubeba seedling treated by shading increased significantly, while ratio of chlorophyll a to chlorophyll b had no significant difference. Content ofchlorophyll b and chlorophyll (a+b) of C. floribunda seedling treated by shading increased significantly, while content of chlorophyll a andcarotenoid had no significant change, ratio of chlorophyll a to chlorophyll b decreased significantly. Initial quantum efficiency (α), maximumphotosynthetic rate (Pnmax), light saturated point (LSP), light compensation point (LCP), dark respiration rate (Rd), apparent photosynthetic electrontransport rate (ETRII), photochemical quenching coefficient (qP) and actual photochemical efficiency (ΦPSII) of C. floribunda seedlings treated byshading decreased. While that of Litsea cubeba seedlings also decreased excluding ETRI and non-photochemical quenching coefficient (NPQ). Theexperiment indicated that L. cubeba and C. floribunda are light-demanding species.