中全新世海南潭门滨珊瑚的生长率特征及其气候意义  

Growth Rate of Porites Corals from Tanmen,Hainan Island:Climatic Significance during

作　　者：李悦儿 余克服 颜廷礼[1,2,3] 江蕾蕾 Yue'er Li;Kefu Yu;Tingli Yan;Leilei Jiang(School of Marine Sciences,Guangxi University Nanning 530004,China;Guangxi Laboratory on the Study of Coral Reefs in the South China Sea Nanning 530004,China;Coral Reef Research Center of China,Nanning 530004,China;Southern Marine Sciences and Engineering Guangdong Laboratory(Zhuhai),Zhuhai 519080,China)

机构地区：[1]广西大学海洋学院,南宁530004 [2]广西大学、广西南海珊瑚礁研究重点实验室,南宁530004 [3]广西大学珊瑚礁研究中心,南宁530004 [4]南方海洋科学与工程广东省实验室(珠海),广东珠海519080

出　　处：《热带地理》2023年第10期1843-1855,共13页Tropical Geography

基　　金：国家自然科学基金项目“全新世南海珊瑚礁发育的时-空差异及其对全球变暖的适应机制”(42030502);“印太交汇区代表性物种的生物多样性演变及生态功能”(42090041);广西研究生教育创新计划项目“海南潭门岸礁珊瑚记录的南海北部中全新世高分辨率气候变化”(YCSW2023085)。

摘　　要：珊瑚生长率是珊瑚古气候研究的重要指标,其反映珊瑚生长快慢,并提供高分辨率的海水表层温度变化信息。中全新世作为当前全球变暖的地质历史相似型,利用珊瑚生长率重建该时期的气候环境状况对于理解现代气候变化的过程及其机制具有重要的参考价值。文章对采自海南潭门珊瑚岸礁的23段中全新世(6143—4356 a BP)滨珊瑚进行生长率分析,并基于该区域现代(2005—2021 AD)滨珊瑚生长率与SST的关系重建了中全新世期间共406 a的年均SST序列。结果显示:1)中全新世滨珊瑚生长率的变化范围为0.607~1.670 cm/a,均值为1.079 cm/a,且存在明显的波动变化过程;2)基于生长率重建的中全新世平均SST为25.7±0.54℃,这与全球变暖程度加剧背景下的现代海温相近;中全新世年均SST的变化范围为24.7~26.8℃,其中5860、5660和5160 a BP为3个显著的低温期;3)对比现代与中全新世(5427—5394、5243—5209、4515—4456和4404—4356 a BP)珊瑚生长率的频谱周期,发现现代与中全新世珊瑚的生长率均存在显著的3~7 a ENSO周期,但中全新世ENSO主周期改变且频率显著降低,表明中全新世的ENSO活动总体偏弱;概率密度函数统计进一步显示中全新世期间ENSO变率存在逐渐增强的趋势。Coral growth rate is a physical index that is particularly closely associated with climatic factors such as Sea Surface Temperature(SST).The growth rate is minimally affected by environmental changes and serves as a high-resolution indicator in the study of climatic and environmental variation,making it a useful tool in paleoclimatic coral research.However,previous research on coral growth rate has primarily focused on the modern period,with limited investigation of the Mid-Holocene,which shares similar climatic characteristics with the current warm period.It is especially important to understand the climate and environmental conditions during the Mid-Holocene to gain insight into contemporary climate change processes and mechanisms.To address this gap,we first collected a modern Porites coral core and 23 Mid-Holocene subfossil coral cores from Tanmen,located on the eastern coast of Hainan Island.Using X-ray radiography and image processing methods,we measured and analyzed the coral growth rates of all cores,resulting in the identification of growth rate patterns during the Mid-Holocene.Additionally,by analyzing the environmental factors that impact modern coral(2005-2021 AD),we established a linear relationship between coral growth rate(L)and SST in Tanmen,expressed as SST=(2.945±0.237)×L+22.481±0.301(1?s.e.).By applying this equation,we reconstructed an annual average SST sequence of 406 years during the Mid-Holocene(6,143-4,356 a BP).The results indicate that the average coral growth rate during the Mid-Holocene was 1.079 cm/a,ranging from 0.607 to 1.670 cm/a,with noticeable fluctuations.The coral growth rate sequence also revealed three consecutive periods of low growth rate,accompanied by a significant increase in interannual variability after 4,515 a BP,resulting in more complex fluctuations.Moreover,the reconstructed SST sequence based on coral growth rate data shows that the mean SST of the Mid-Holocene was 25.7±0.54℃,which is comparable to the modern SST in the context of global warming.The average

关 键 词：海表温度 ENSO 中全新世 珊瑚生长率 南海北部 

分 类 号：P736.4[天文地球—海洋地质]