Community Of Macrobenthic And Shorebirds In YanCheng Nature Reserve

Shorebirds (Charadriiformes) are typical waterbirds wading in wetlands, as a very important component of the coastal and lake ecological system, the number of shorebirds is a measure of wetlands value. The food provided by stopover sites along the flyway are vital for shorebirds to refuel and finish their migration to the breeding ground. Yancheng Nature Reserve is an important stopsite for shorebirds in the East Asian-Australasian Flyway (EAAF). In order to study the role of Yancheng Nature Reserve on supporting the migration of shorebirds and provide scientific data to shorebirds conservation. In Sheyang estuary, the macrobenthos are the main food resources of shorebirds, the paper studied the resources status of macrobenthos, analysed the niche of macrobenthos on the tidal flat and the effect of Spartina alterniflora invasion on them.in addition, studied the resources status of shorebirds during the northward and southward migration and wintering period and the relationship between macrobenthos and shorebirds in spring and winter. The main results were as follows:1.We found a total of 16 species of macrobenthic on intertidal flats of Sheyang estuary, Yancheng Nature Reserve. The species numbers found at 4 sampling plots (intertidal zone with Spartina alterniflora, high, middle and low tidal flat without plants) were different. The habitat variation was much more important reason of macrobenthic community distribution than the season. The Potamocorbula ustulata and Macoma praetextadensity had broader niche breadths, however the Glaucomya chinensis and Mactra veneriformis were narrower. There were great differences in the niche overlaps among all the species. The niche breadth and niche overlaps had close relationship with the species spatio-temporal distribution and quantity.2. We found a total of 22 species of macrobenthic on tidal flats in Sheyang estuary, Yancheng Nature Reserve. The compositions of species between 2 contrast team(area with Spartina alterniflora and area without Spartina alterniflora) of each group were different. The effect of Spartina alterniflora from different habitats was different: either reduced the number of species, density, biomass and biodiversity in intertidal flat or enhanced these indices except for biomass in creek, however, the effect of Spartina alterniflora invasion on all indices was inconsistent in supralittoral zone.3. A total of 22 species were observed at Sheyang Estuary, Yancheng Nature Reserve., we can found all spcies in spring,13 species can be found in autumn, there were only 8 species in winter. The Dunlin(Calidris alpina) was the dominant species in 3 seasons and the percentage of number of shorebirds was 3:1:1.5 in spring, autumn and winter. The density of shorebirds existed significant difference among habitats in spring, autumn and winter; the great number of species and Shannon-weinner diversity index were all found at creek in 3 seasons, The density of shorebirds was the much bigger at the high tidal flat without plants, middle tidal flat without plants and creek, the number of shorebirds were the biggest at high and middle tidal flat without plants; the shorebirds were also found at aquaculture ponds, but the density was very low and most of them inhabited in there. The migratory peak period was the last ten to twenty day in April, and finish at the last ten to twenty day in May, different species had few difference at the migratory peak period.4. The habitat with higher density of macrobenthic had much more shorebirds. the densities of shorebirds with bill-length beyond 50mm were remarkable positive correlation with the densities of Crustacean, the densities of shorebirds with bill-length below 25mm were remarkable positive correlation with the densities of Bivalve, however, the densities of shorebirds with bill-length between 25-50mm weren't remarkable correlation with the densities of several forms of macrobenthic in spring; but the densities of shorebirds with 3 kind of bill-length weren't remarkable correlation with the densities of several forms of macrobenthic in winter. The densities of visual continuous shorebirds were remarkable positive correlated with the densities of Crustacean, the densities of Tactile continuous shorebirds were remarkable positive correlation with the densities of Bivalve, however, the densities of Pause-travel shorebirds weren't remarkable correlation with the densities of several forms of macrobenthic in spring; 3 foraging strategy shorebirds weren't remarkable correlation with the densities of every forms of macrobenthic in winter. The percentages of each categories of shorebirds weren't remarkablely correlated to the percentages of epifauna and infauna life forms. The species with same foraging strategy had either different main food or many kinds of food. the gained food affect foraging behaviour of shorebirds, for same type food, they are apt to select the species with high density.