Changes in the Macrobenthic Faunal Community during Succession of a Mangrove Forest at Zhanjiang, South China

A chronosequence was used to study the community structure of the macrobenthic faunal community during succession of the mangrove forest at Zhanjiang, South China. The four successional stages studied were (from primary to late) unvegetated shoal, the Avicennia marina community, the Aegiceras corniculatum community, and the Bruguiera gymnorrhiza + Rhizophora stylosa community. Faunal density, the diversity index, species richness, and evenness index were highest in the unvegetated shoal (189 individuals/m(2), 1.97, 3.48, and 0.74, respectively, in the wet season; 105 individuals/m(2), 1.77, 2.20, and 0.84, respectively, in the dry season) and lowest in the B. gymnorrhiza + R. stylosa community (35 individuals/m(2), 1.04, 1.10, and 0.57, respectively, in the wet season; 46 individuals/m(2), 0.86, 1.16, and 0.66, respectively, in the dry season). The values for these community parameters decreased with succession. Hierarchical clustering indicated that the distribution of the macrobenthic fauna closely corresponded with the successional stages. Correlation analysis and canonical redundancy analysis (RDA) indicated that the changes in the macrobenthic fauna with mangrove succession were associated with the aboveground vegetation (mainly crown breadth and tree height) and soil physicochemical properties (mainly soil organic matter and total nitrogen content). Several species of macrobenthic fauna were only detected in certain stages of succession, suggesting that they may be biological indicators of succession.