广西涠洲岛造礁珊瑚种群结构的空间分布

对2007年和2008年调查的涠洲岛沿岸海域垂直海岸方向的6条主剖面上20条分断面的影像资料、样品鉴定等资料的分析,涠洲岛石珊瑚共出现10科22属46种,9个未定种;角蜂巢珊瑚属(Favites)、滨珊瑚属(Porites)、蔷薇珊瑚属(Montipora)为优势类群,其属级重要值百分比分别为25.78%、17.47%、15.11%;各主剖面珊瑚种群优势类群分布各有差异,以西南部的W2、东北部的W5的珊瑚属种为较多,均为8科13属,其石珊瑚属种分布均匀度略高;涠洲岛珊瑚分布自岸向海分为砂砾及珊瑚断枝带、石珊瑚稀疏带、石珊瑚繁盛带、柳珊瑚繁盛带4 个生物地貌带,石珊瑚分布较多的石珊瑚繁盛带主要分布于-1.39--5 m的水深范围内。石珊瑚形态组合以块状/亚块状与板块状为主要类型,覆盖程度以块状/亚块状占优。调查区受1998年的"厄尔尼诺现象"引起的全球性极高温事件和2008年1-2月的极低温气候事件及地域性不合理人类活动胁迫影响较大,枝状形态石珊瑚覆盖度、优势程度下降,已退出属种优势组合。

Spatial pattern of Scleractinian coral Population Structure in Weizhou Island, Beihai, Guangxi

Based on the analysis of image data and sample identification of 20 subsections on 6 principal sections in the direction perpendicular to the coast line around coast area of the Weizhou Islands conducted during 2007 to 2008, there are 46 species, 22 genuses and 10 families of coral and 9 species indeterminate found in coral reef area of the Weizhou Islands; Favites, Porites and Montipora are dominant groups whose important value percentages of genuses are 25.78%, 17.47% and 15.11% respectively; the distributions of dominant groups of coral groups on each principal section are different, and there are more genuses and species of coral in W2 of the southwest and W5 of the northeast, in both of which there are 13 genuses belonging to 8 families with rather high uniformity of distribution of scleractinia; the distribution of coral in the Weizhou Islands is divided into 4 biogeomorphological zones as gravel and coral fragmentation zone, scleractinia rarefaction zone, scleractinia prosperity zone and gorgonian prosperity zone, and the scleractinia prosperity zone with more distribution of scleractinia is mainly distributed in the scope from -1.39 m to -5 m deep. Scleractinia takes massive/submassive form and plate-like form as its major shapes, and the massive/submassive form is dominant in the degree of coverage. In the surveyed region which is affected greatly by global extreme high temperatures caused by El Nino phenomenon in 1998 and extreme low temperature climate from January to February in 2008 and unreasonable human activites, the coverage and dominance of branching form coral have decreased and it has been out of dominant species combination.