- 责任者：Su Ruixia (Key Laboratory of Marginal Sea Geology ; South China Sea Institute of Oceanology ; Chinese Academy of Sciences ; Guangzhou 510301 ; China) ; Sui Dandan
- 刊名：Quaternary Sciences
- 出版年：2012
- 卷期：32(6)
- 关键词：珊瑚纲 ; Anthozoa ; 二氧化碳 ; carbon dioxide ; 全球变暖 ; global warming ; 南海 ; South China Sea
- 页码：p.1087-1106
- 图表：10 illus., 3 tables, 72 refs.
- 分类号：1400
- issnNo：ISSN1001-7410
- isbnNo：CN11-2708/P
The 11 modern Porites corals,including Porites lutea and P.lobata,spanning last 15 to 48 years,were collected from 3～4m water depth at Nansha Islands of the southern South China Sea（SCS）in July～September 2008.The SCS is not only influenced by Asian monsoon but also adjusted by the north western Pacific Ocean.At Nansha Islands,the sun directly shines twice from March 27 to April 21 and August 21 to September 16,and both annual average air temperature and SST are more than 27℃. ＂wet seasons＂ are 7 months from June to December with highest rainfall and cloud cover in September; By contraries,＂dry seasons＂ are 5 months from January to May with lowest rainfall and cloud cover in April.Natural geographical conditions are suitable for reef coral living.Extension rate represents coral upward linear extension growth per year（cm/a）,density represents coral skeletal quality per cm^3（g/cm^3）reflecting comprehensive environment quality; Calcification rate represents quality of calcium carbonate per cm^2 and year（g/cm^2 •a） excreted by coral,and calculated from the product of extension rate and density.In this study,the 3 growth parameters of the 11 Porites colonies were obtained along their main growth axes using digital X-radiography image of which the reative density is transferred to density with measured true density.The results show that their average extension rate is 0.96±0.05cm/a,increasing 10.77% in the last 16 years with a rate of 0.67% /a; The average density is 1.17±0.03g/cm3,decreasing 6.92% with a rate of -0.43% /a; The average calcification rate is 1.13±0.05g/cm2 •a,increasing 2.69% with a rate of 0.17% /a.Two coral species of P.lutea and P.lobata show slightly different variations in their 3 growth parameters.Standard diviation analysis indicate that density is less variable than extension and calcification rate for Porites,which reveal that increase in calcification rate is mainly induced by increase in extension rate.Our analysis summarize three vriational forms for the three growth parameters in 11 Porites colonies： 1）A lot of corals assume increase in extension and calcification rate and decrease in density; 2）A few of corals assume increase in all of the 3 growth parameters; 3）A few of P.lobata colonies show decrease in all of the 3 growth parameters.Linear regression analysis indicates that increase or decrease in the 3 growth parameters correlates significantly with increase in both CO2 concentration and temperature.However,positive responses of extension and calcification rate and negative response of density are much stronger than their opposite responses.Farther comprehensive analysis suggests that increase in SST induced by increase in anthropogenic greenhouse gas strengthens coral respiration so that a lot of corals increase their extension and calcification rates but decrease their densities.Moreover,due to effects of growth difference in sample individuals and local environmental factors,a few of corals may have different abilities to respond to rise in atmosperic CO2 concentration and global warming.