Ecological indicators showing the succession of macrofauna communities in Sonneratia apetala artificial mangrove wetlands on Qi’ao Island at Zhuhai, South China

Abstract

The Sonneratia apetala artificial mangroves in the intertidal zone of Da Wei Bay at Qi’ao Island of Zhuhai, South China were chosen as the macrofauna succession plots while bare tidal flats of the same size were established as control plots in surrounding interference-free areas. Conventional change indicators of community structure, such as biomass and biodiversity, and indicators, such as exergy and specific exergy, which reflect the information change of overall communities, were used to analyze the succession of macrofauna communities in S. apetala artificial mangroves. The similarities and differences in variation tendency of the different ecological indicators and their reflected ecological principles were compared. The results showed that from D-1 to D-1275 after planting S. apetala, the biomass of the macrofauna communities first increased, which was then followed by an increase in the network relationship between the macrofauna communities (analysis of the Pielou evenness index and Shannon-Wiener diversity index). The system information (specific exergy) increased the slowest. Between D-1460 and D-2370 after planting S. apetala, there was a decrease in biomass, network structure, and system information in the succession plots. After the decrease in the system information (the specific exergy), there was a decline in the network relationships (Pielou evenness index and Shannon-Wiener diversity index). Biomass was the last indicator to decrease. The similarities and differences among the different ecological indicators varied during the succession process, which reflected the relativity and differences among the indicators. This study suggested that, although the species diversity index can be an effective indicator of two types of changes (network structure and system information), it was quite clear that species diversity measurement was not suitable for expressing the changes in biomass during the succession process. While exergy and specific exergy can provide useful information about the structural development of communities, they cannot identify the information state of the system. Therefore, when evaluating macrofaunal succession in S. apetala artificial mangrove wetlands, it would be better to apply a number of different ecological indicators, rather than just one single indicator.