中文摘要：

在边缘的海的浮游植物生产率和社区结构在过去的三十年期间显著地被改变了，但是区分在气候变化和人为的活动之间的强迫的机制仍然是挑战。二的高时间决定 biomarker 记录 < 啜 class= “ a-plus-plus ” > 210 Pb 过时的沉积核心(#34：28.5 据獥椠 ? 桴 ? 楤敶獲瑩 ? 景琠敨戠捡整楲污挠浯畭楮祴椠 ? ?晲捡 ? 畢歬猠楯獬 ?? 愿摮 ?? ?愠摮爠楨潺灳敨敲猠楯獬戠瑥敷湥瀠敲楣楰慴楴湯琠敲瑡敭瑮 ? 椠据畬楤杮挠湯牴汯? 慂瑣牥慩眠牥 ? 摩湥楴楦摥甠楳杮琠敨栠杩 ? 桴潲杵灨瑵 ?? 猠煥敵据湩 ? 敭桴摯 ? 敗漠瑢楡敮 ?? 潴慴????? 灯楴業敺 ? 敳畱湥散 ? 眠瑩 ?? 敭湡瘠污敵漠 ?? 水名？

英文摘要：

Phytoplankton productivity and community structure in marginal seas have been altered significantly during the past three decades, but it is still a challenge to distinguish the forcing mechanisms between climate change and anthropogenic activities. High time-resolution biomarker records of two 210Pb-dated sediment cores（#34： 28.5°N, 122.272°E; CJ12-1269： 28.861 9°N, 122.515 3°E） from the Min-Zhe coastal mud area were compared to reveal changes of phytoplankton productivity and community structure over the past 100 years. Phytoplankton productivity started to increase gradually from the 1970 s and increased rapidly after the late 1990 s at Site #34; and it started to increase gradually from the middle 1960 s and increased rapidly after the late 1980 s at Site CJ12-1269. Productivity of Core CJ12-1269 was higher than that of Core #34. Phytoplankton community structure variations displayed opposite patterns in the two cores. The decreasing D/B（dinosterol/brassicasterol） ratio of Core #34 since the 1960 s revealed increased diatom contribution to total productivity. In contrast, the increasing D/B ratio of Core CJ12-1269 since the 1950 s indicated increased dinoflagellate contribution to total productivity. Both the productivity increase and the increased dinoflagellate contribution in Core CJ12-1269 since the 1950–1960s were mainly caused by anthropogenic activities, as the location was closer to the Changjiang River Estuary with higher nutrient concentration and decreasing Si/N ratios. However, increased diatom contribution in Core #34 is proposed to be caused by increased coastal upwelling, with higher nutrient concentration and higher Si/N ratios.