近130年来北黄海浮游植物生产力和群落结构变化的沉积物生物标志物记录

SEDIMENT BIOMARKER RECORDS OF PHYTOPLANKTON PRODUCTIVITY AND COMMUNITY STRUCTURE CHANGES OF THE NORTH YELLOW SEA AND ITS IMPLICATIONS FOR CLIMATE CHANGE AND ANTHROPOGENIC ACTIVITIES OVER THE LAST 130 YEARS

类脂生物标志物已被广泛用于重建海洋浮游植物生产力及群落结构变化,但是,在北黄海和渤海的应用还不多。在210Pb定年的基础上,对北黄海西南部箱式柱状样B25进行了生物标志物分析,利用其含量及相对比例变化重建了北黄海过去130年来浮游植物生产力及群落结构变化,并探讨了其变化规律对气候变化和人类活动的指示作用。结果表明:过去130年来,浮游植物生产力总体呈上升趋势,在1975年后显著增加。揭示了一种在我国边缘海群落结构变化的新特征,在1965—1990年间呈现硅藻比例下降和甲藻比例增加,而1990年之后则表现为硅藻比例增加和甲藻比例下降。北黄海近百年来浮游植物生产力的提高主要与东亚冬季风的增强和陆源输入增加有密切关系,而群落结构的改变可能是人类活动和气候变化共同作用的结果。

Biomarkers are now widely used in reconstruction of marine phytoplankton productivity and community structure changes.However,there are few biomarker records in the North Yellow Sea（NYS）and the Bohai Sea（BS）.In this study,contents and ratios of various biomarkers for a210 Pb dated core B25 from the North Yellow Sea are applied for the reconstruction of changes in phytoplankton productivity and community structure over the last 130 years.The results indicate that phytoplankton productivity increased gradually over the last 130 years and increased rapidly after 1975.From 1965 to 1990,the relative contribution of dinoflagellates increased and the relative contribution of diatoms decreased,but the trend was opposite since 1990.It suggests that the strengthened East Asia Winter Monsoon（EAWM）and increased terrestrial inputs caused higher phytoplankton productivity.The phytoplankton community structure changes are attributed to both anthropogenic activities and climate changes.