文献类型：期刊文献

中文题名：珠江口近2000年来营养状况演变的氮同位素沉积记录

英文题名：Sedimentary nitrogen isotopic record of the evolution of nutrient status in the Pearl River Estuary over the past 2000 years

作者：王利伟[1,2];叶丰[1];黄超[3];韦刚健[1]

机构：[1]中国科学院广州地球化学研究所,同位素地球化学国家重点实验室,广东广州510640;[2]中国科学院大学,北京100049;[3]广东海洋大学海洋与气象学院,广东湛江524088

年份：2024

卷号：53

期号：4

起止页码：504

中文期刊名：地球化学

外文期刊名：Geochimica

收录：北大核心2023、CSTPCD、、CSCD2023_2024、北大核心、CSCD

基金：国家自然科学基金项目(42073074、41991325);中国科学院青年创新促进会项目(2019346)联合资助。

语种：中文

中文关键词：珠江口;沉积记录;氮同位素;气候变化;人类活动

外文关键词：the Pearl River Estuary;sediment records;nitrogen isotopes;climate change;human activity

中文摘要：近2000年以来河口近海氮循环变化的历史及其与人类活动–气候变化的关系研究,对于理解陆海过渡带生态环境演变规律及控制机制具有重要意义。本文通过对珠江口外高分辨率沉积物岩心(WS)总氮同位素(δ^(15)Nbulk)和一系列地球化学指标(TOC、TN、C/N、δ^(13)C、Ti、Al/K等)的综合分析,重建了珠江河口近2000年水体营养化程度(硝酸盐利用率)的演变规律,同时结合研究区的气候环境变化记录和人类活动历史,探讨了河口氮循环在气候变化和人类活动双重压力下的变动机制。结果显示,近2000年以来珠江口沉积物δ^(15)Nbulk的变化特征反映了海洋浮游植物对表层水体硝酸盐利用率的演变过程,即水体的营养状况变化。表层水体氮营养的供应与陆源径流量和水层结构有关,主要受到东亚夏季风(EASM)强度的调控。过去2000年持续增强的人类活动加速了陆源营养盐的输入,使表层水体的营养状况得到很大改善,不断提升河口初级生产力,进而与EASM强度的变化产生了偏移。近2000年以来,珠江口水体硝酸盐利用率整体上呈波动下降的W形,表明营养供应不断增强,而日益增强的人类活动和气候变化共同驱动着珠江口水体营养程度的演变。

外文摘要：In this paper,we investigated sedimentary bulk nitrogen isotope values(δ^(15)Nbulk)and related geochemical indexes(TOC,TN,C/N,δ^(13)C,Ti,and Al/K)in a high-resolution sediment core(WS)collected from the Pearl River Estuary(PRE),South China.Nutrient status(i.e.,the degree of nitrate utilization by phytoplankton)and its driving mechanism in the PRE over the past 2000 years were reconstructed by theδ^(15)N records as well as the climatic and human activities records.The results showed that theδ^(15)Nbulk record in the PRE reflects the degree of nitrate utilization by phytoplankton in the surface water.Its nutrient supply is related to the upper water structure and river runoff,which was mainly regulated by the East Asian summer monsoon(EASM).The strengthened human activities and weakened EASM over the last 2000 years have promoted the input of terrigenous nutrients and improved the nutrient status of the PRE.Over the past 2000 years,the nitrate utilization rate in the PRE showed a W-shape of fluctuation and decline,and the nutrient supply was continuously enhanced.The increasingly enhanced human activities and climate change jointly drove the trophic evolution of the PRE.