Habitat Diversity Of Meiofaunal Community In Quanzhou Bay Intertidal Zone

The intertidal zone refers to parts of the beach that are covered with water during the high tides and are exposed during low tides. There are sandy areas, rocky cliffs and wet lands in the intertidal zone. The environment here is subject to constant change due to the tides. Meiofauna is an important part of intertidal ecosystems, yet there is few studies implemented on meiofauna in the intertidal zone especially in mangrove and grass wetlands in China. It leads to a lack of biodiversity and ecosystem integrity in intertidal zone.Ecological investigation has been launched and samples of meiofauna were collected in Quanzhou Bay intertidal zone from April,2011to January,2012. Group composition, abundance, biomass and biodiversity of meiofauna as well as species composition, abundance, biomass and dominant species of free-living marine nematodes were analysed so as to provide basic data of meiofaunal diversity in group and biotope in Quanzhou Bay intertidal zone and consummate the data bank of free-living marine nematodes in China.Following are the main research achievements.(1) Group composition of meiofauna.12meiofaunal groups were collected in4habitats in four seasons, including free-living marine nematodes, benthic copepods, oligochaeta,polychaeta, turbellaria,insect, amphipoda, foraminifera,ostracoda, gastropoda, bivalvia and nemerteans. Among them, free-living marine nematodes was the dominant group, which had a percentage of80.61%in total abundanceof meiofauna. While the number of foraminifera is more than others in Xunpu intertidal zone. Compared with other researched mangrove wetlands in China, gastropoda and bivalvia are only found in Quanzhou Bay.(2) Abundance and biomass of meiofauna. In four seasons and habitats, the abundance was highest vnAegiceras corniculatumm winter (2104.9±944.3ind.10cm-2), while lowest in Kandelia Candel in autumn (273.0±109.0ind.·10cm-2). In four seasons, the biomass was highest in spring and lowest in autumn.Among proportion of biomass in each groups, foraminifera is highest (79.8%), followed by nematodes (8.44%) and copepods (4.21%). Univariate Two-way ANOVA tests showed that there were highly significant differences among different seasons and among different habitats. And the season×habitats interactionwas highly significant different as well.(3) Diversity indices of meiofauna. The highest values of abundance index (d), evenness index (J*) and Shannon-Wiener index (H’) appeared in different seasons and habitats. It proved that the hypothesis of habitat diversity in the intertidal zone and showed that the characteristics of short life history of meiofauna.(4) Abundance and biomass of free-living marine nematodes.In four seasons, the highest average abundance and biomass were both in winter, followed by summer and winter. In four habitats, the highest average abundane and biomass were both in oyster-stone flats, followed by Spartina alterniflora and A. corniculatum. The highest number of dominant species was in spring, while lowest in spring. Among them, the dominant species was Spilophorella sp.l in both spring and winter. And Sabatieria sp. was the dominant species in summer and autumn.(5) Species composition of free-living marine nematodes. A total of105free-living marine nematode species were identified in four seasons, which belonged to3orders,27families and76genera. Among them,20genera were only reported in Quanzhou Bay compared with other intertidal zones in China. In four seasons and habitats, the highest species number was in S. alterniflora in autumn and the lowest was in A. corniculatum in spring. Univariate Two-way ANOVA tests showed that there were highly significant differences among different seasons and among different habitats. And there was no significant differentin the seasonsx habitats interaction.(6) Trophic structure of free-living marine nematodes. According to the statistics of marine nematodes species number, non-selective deposit feeders (1B) had the most species, followed by selective deposit feeders (1A), predators (2B) and epigrowth feeders (2A).According to the statistics of marine nematodes abundance,non-selective deposit feeders (IB)had the most speciesand selective deposit feeders (1A) had the least species. (7) Meiofauna was affected by sediment particle size in Quanzhou Bay intertidal zone.Pearson correlation analysis showed that mud temperature, clay, sand, silt and median diameterwere the factors those impacted abundance of meiofauna; clay, sand, silt and median diameter were the factors those impacted biomass of meiofauna; salt and clay were the factors those impacted abundance of nematodes; salt, clay, silt, sand and medium were the factors impacted species number of nematodes.