A biological trait approach to assess ecological functions of macrobenthos at different stand age of rehabilitated Sonneratia apetala mangrove

Based on the investigation data collected from mudflat, rehabilitated Sonneratia apetala mangroves at stand age of 8, 9, 14, 16 and 20 years and Avicennia marina natural mangrove forest of Futian National Nature Reserve in Shenzhen, we studied the ecological functions of macrobenthic community at different stand age by analyzing biological trait patterns, functional diversity and functional redundancy. Results show that the mudflat, 8-, 9-, 14- and 16-year-old stand rehabilitated S.apetala mangroves, and 20-year-old stand natural mangrove forest had different trait patterns. The more complex the structure of the habitat and the higher the content of organic matter were, the more species with lower mobility, smaller body size, surface crawler/swimmer, planktotrophic, deposit-feeder and herbivore were observed. Generally, the functional diversity increased at first then decreased with increasing habitat structure and sediment organic matter content. The functional redundancy was generally high in the mangrove. To sum up, moderate increase in habitat structure of mangrove is more beneficial to the ecological functions of macrobenthic community.