Seasonal variations of solar UV radiation effects on phytoplankton assemblages from coastal waters of the South China Sea
会议名称：《中国海洋湖沼学会藻类学分会第七届会员大会暨第十四次学术讨论会》
会议日期：2007年
关 键 词：productivity phytoplankton ultraviolet radiation tropical environments
摘 要：We carded out experiments to evaluate the impacts of UV radiation(UVR, 280-400nm)on photosynthetic carbon fixation of phytoplankton assemblages from coastal waters of the South China Sea during March 2004 - Sep *** surface samples were taken and exposed to different radiation treatments using sharp cut-off filters,receiving full spectrum of solar radiation(PAB,280-700nm),PA(320-700nm) that filtered out of UV-B(280-320nm),and P(400-700nm)that cut off both UV-A and UV-B(320-400nm).Solar UVR significantly inhibited photosynthetic carbon fixation rates of phytoplankton assemblages during spring and winter,with UV-A accounting for most of the observed inhibition;little UVR-induced inhibition was observed during *** view of the photosynthetic performance among different weather conditions,phytoplankton cells appeared to be able to utilize UVR under low levels of solar irradiances on the cloudy *** mean values of assimilation number(ASN)were 2.83(spring)7.62(summer),and 4.35μg C(μg chl a)h (winter)under PAR,and were 1.57,5.70,2.71μg C(μg chl a)hunder PAR+UVR, *** a concentration ranged from 0.99-1.12 in the spring, 1.12-16.2 in the summer and 0.72-1.35 μg/L in the *** period showed the highest ASN and the lowest UVR-related *** the summer period, higher temperature might have led to faster enzymatic reactions for the repair of UVR-induced damages,and stratification(less vertical mixing)could result in higher abundance of the species tolerating high levels of PAR and UVR.