ABSTRACT
As the intersect area between marine and terrestrial ecosystems, intertidal zones provide the suitable habitat environment
for various macrobenthos community However, the construction of tidal barriers in intertidal zones might change the
community structure of macrobenthos substantially. In this paper, we surveyed the differences of macrobenthos
community, the dominant species, and biodiversity between inside and outside of the tidal barriers in Yiqianer forest zone
in Yellow River Delta in April and May, 2014. The survey results showed that 16 and 7 species macrobenthos existed in
outside of the tidal barriers (seaward side) and inside of the tidal barriers (landward side), respectively. Polychaetes and
mollush macrobenthos are the dominant species in the seaward side, while insect is in the landward side and polychaetes
and mollush macrobenthos almost disappeared. Average biomass and abundance in the seaward side is 14.18 g/m2 and
101.85 ind/ m2; while it is 7.25 g/m2 and 1424.00 ind/ m2 in the seaward side, respectively. We calculated the biodiversity
indexes, such as Shannon-Weiner index, Pielou evenness index, Simpson index, and Margalef species richness index,
and all of them have decreased from seaward to landward sides. Maybe there are two reasons capable to explain the
abnormal ecological succession. On the one hand, the barriers separate the erosion of the tides and the salinity of water
and sediments deceased in the landward side; On the other hand, the construction of tidal barriers cut off the passage of
macrobenthos returning to low tidal zones for breeding, and destroy the biological connectivity. In addition, through NMDS
and clustering analysis for macrobenthos communities in study area, we can divide them into three groups. There is
strong connection between geographical distance and ecological similarity among macrobenthos communities in study
area. An accumulative effect of barriers on intertidal zones works obviously. Therefore, as a result, the above, the
construction of tidal barriers has changed the community structure of macrobenthos substantially, and the abnormal
ecological succession is in process.