琼东海域橙黄滨珊瑚骨骼生长特性及其主要影响因素

Growth characteristics of Porites lutea skeleton in east sea area of Hainan Island,China and main affecting environmental factors

基于珊瑚骨骼X射线照片,使用CoralXDS软件,对海南岛(琼)东部海域的橙黄滨珊瑚生长特性进行研究,获取了百年来的年生长率(ER)、骨骼密度(D)和钙化速率(CR)3种生长参数.结果表明:该橙黄滨珊瑚ER的变化范围为0.49~1.10 cm·a^(-1),年均值0.76cm·a-1;D的变化范围1.11~1.35 g·cm^(-3),年均值1.22 g·cm^(-3);CR的变化范围为0.55~1.41g·cm^(-2)·a^(-1),年均值0.94 g·cm^(-2)·a^(-1).统计分析表明,研究海区表层水温(SST)是橙黄滨珊瑚骨骼生长参数变化的主要环境影响因素,对ER和CR的控制较强,对D的影响较弱,但总体上3项生长参数都随SST升高而增大.光照、盐度和水动力条件等是次要影响因素.台风和强热带风暴对琼东海域橙黄滨珊瑚骨骼密度条带分布的影响也较为显著.复杂的气候环境,赋予了橙黄滨珊瑚骨骼多变的生长模式.过去一个世纪以来,琼东海域年平均表层水温显著上升,气候倾向率为0.15℃·(10 a)^(-1),SST上升分为两个阶段,20世纪40年代初和80年代初,人类活动加剧和全球气候变暖是导致琼东海域SST显著上升的原因.

The growth characteristics of Porites lutea skeleton in east sea area of Hainan Island were studied by Coral XDS software based on X-ray chronology. The growth parameters obtained included extension rate（ ER）,skeleton density（ D）,and calcification rate（ CR）. The results showed that ER varied from 0.49 to 1.10 cm·a-1 with an annual average of 0.76 cm·a-1,D varied from 1.11 to 1.35 g·cm-3 with an annual average of 1.22 g·cm-3,and CR varied from 0.55 to 1.41 g·cm-2·a-1 with an annual average of 0.94 g·cm-2·a-1. Statistical analyses indicated that sea surface temperature（ SST） was the key environmental factor that controlled the growth characteristics,as it highly co-varied with ER and CR,less so with D. All of the three growth characteristics increased with the increase of SST. There were other factors that influenced the growth characteristics of the coral column,such as light,water salinity,and hydrodynamics,etc. In addition,typhoon and severe tropical storms also imposed a significant impact on the growth pattern of Porites lutea coral.The change in growth pattern of coral skeleton in east of Hainan Island was a response to complex climate fluctuation. Over the past century,SST of east Hainan Island dramatically increased at a rate of 0.15 ℃ ·（ 10 a）-1. The SST increase trend for the oceanic region could be divided into two stages,early 1940 s and early 1980 s. The human activities and global warming was the main causes for the increase of SST.