南海滨珊瑚骨骼密度带的季节特征及其主要环境影响因素  

Seasonal Patterns and Major Environmental Influences of Skeletal Density Bands of Coral Porites from the South China Sea

作　　者：韦雯雯[1,2] 施祺[1] 余克服[1,3] 陶士臣[1] 万阳[4] 

机构地区：[1]中国科学院南海海洋研究所,中国科学院边缘海地质重点实验室,广州510301 [2]中国科学院大学,北京100049 [3]广西大学珊瑚礁研究中心,南宁530004 [4]中国地质大学资源学院,武汉430074

出　　处：《热带地理》2016年第6期923-934,共12页Tropical Geography

基　　金：国家重大科学研究计划项目(2013CB956101);国家自然科学基金项目(41272199、41302281)

摘　　要：滨珊瑚(Porites)是南海造礁石珊瑚群落的主要优势种之一,广泛应用于珊瑚礁生态以及高分辨率气候环境响应和重建研究。滨珊瑚不同季节生长形成的骨骼密度条带是开展相关研究的重要基础,而前人对于滨珊瑚骨骼密度带季节性的认识多是基于单一地点的样品,存在地域的差别或矛盾。选取南海不同地点典型珊瑚礁区包括北部海南文昌、中部西沙群岛永兴岛和盘石屿、南部南沙群岛美济礁的4个现代活体滨珊瑚骨骼样品,利用数字影像分析方法以及电感耦合等离子体原子发射光谱和气体稳定同位素比质谱仪分别分析了滨珊瑚骨骼密度条带影像灰度和地化指标(Sr/Ca和δ^(18)O)。结果显示,滨珊瑚样品骨骼密度和地化指标都呈现显著的季节变化。结合海温数据,揭示出样品骨骼密度带季节特征的地域差异,其中,北部文昌滨珊瑚样品骨骼高密度带形成于夏季,低密度带形成于冬季;中部永兴岛样品高密度带形成于秋季,低密度带形成于春季;盘石屿样品高密度带形成于春季,低密度带形成于秋季;南部美济礁样品高密度带形成于冬季,低密度带形成于夏季。采用广义加性混合模型进一步分析了滨珊瑚样品骨骼密度与3个主要环境影响因子(海温、光照和盐度)的响应关系。结果表明:不同地点滨珊瑚样品的骨骼密度与主要环境因子的关系也各有不同,考虑样品个体和地点的随机效应,4个地点滨珊瑚样品的骨骼密度整体上与海温和光照存在非线性响应关系,反映了在南海大空间尺度上,海温和光照可能是影响滨珊瑚样品骨骼密度季节变化的主要环境因素。Porites corals are dominant in the South China Sea （SCS） coral reef systems. Porites have been widely used in the coral-based high-resolution paleo-climate reconstructions, based on their seasonal skeletal density bands. There were local difference and contradictions on the seasonal skeletal density bands of Porites attributing to the single sample site in the previous studies. In this paper, gray value and geochemical proxies （Sr/Ca and 3180） were analyzed by using digital image processing, inductively coupled plasma atomic emission spectrometry and gas isotope ratio mass spectrometer in 4 living Porites collected from four typical coral reef sites in the northern, middle and southern SCS respectively, including Wencbang, Yongxing Island, Panshiyu Reef, and Meiji Reef. As compared with the sea surface temperatures, the skeletal density showed significant seasonal variations in all samples, but the seasonal pattern of skeletal density band varied within the different sites. The high and low skeletal density bands formed separately in summer and winter in the Porites sample from Wenchang in the northern SCS; the high and low density bands developed separately in autumn and spring in the skeletal samples from Yongxing Island and in spring and autumn in the sample from Panshiyu Reef respectively in the middle of the SCS; and the high and low density bands of the skeletal sample occurred separately in winter and summer at Meiji Reef in the southern SCS. The Generalized Additive Mixed Model was applied to reveal the relationship of skeletal density to sea surface temperature, sea surface salinity and net shortwave radiation, respectively. Regardless of the random effects from sample individuals and sites, the results showed the different relationship between skeletal gray values and environmental factors in four sites： sea surface temperature and net shortwave radiation had negative correlation to the skeletal gray values in Wenchang; while skeletal gray values in Meiji Reef had strongly positive correlation

关 键 词：滨珊瑚 骨骼密度 地化指标 环境因子 

分 类 号：Q954[生物学—动物学]