迁徙停歇期鸻鹬类在崇明东滩潮间带的食物分布

Food supply in intertidal area for shorebirds during stopover at Chongming Dongtan, China

崇明东滩是鸻鹬类在东亚-澳大利西亚迁徙路线上重要的迁徙停歇地,滩涂上的底栖动物为迁徙的候鸟提供了丰富的食物来源。采用圆筒取样法对崇明东滩潮间带的大型底栖动物群落进行了研究。研究表明,该区域的大型底栖动物主要有腹足类、双壳类、甲壳类、多毛类环节动物及昆虫幼虫等类群。其中以腹足类密度最高((2805±360)个/m2),约占底栖动物总密度的80%。其次为双壳类,密度为(320±31)个/m2。双壳类的生物量(湿重)为(51.4±7.8)g/m2,腹足类(38.7±5.1)g/m2,两者占底栖动物总生物量的90%以上。不同类群的底栖动物在潮间带的空间分布上有显著差异。腹足类主要分布在海三棱藨草带,双壳类在海三棱藨草外带至光滩区域分布较多。从空间分布来看,腹足类在崇明东滩的北部区域分布较多,在南部区域则明显减少。双壳类在南北各条样线上的平均密度没有显著差异。除双壳类在秋季迁徙期的密度高于春季迁徙期外(P<0.001),其他类群的底栖动物在春季和秋季迁徙期的密度均无显著差异(P>0.05)。

The wetland in Chongming Dongtan is an important stopover site for migratory shorebirds along the East Asian-Australasian Flyway. The high abundance macrobenthos in Chongming Dongtan allow migratory birds to refuel during stopover. This study analyzed the distribution and density of macrobenthos in the intertidal zone. Results showed that the macrobenthos are mainly consisted of gastropods, bivalves, polychaetes, crustaceans and insect larvae. The density of gastropods （（2805 ±360）ind./m^2） was the highest, accounting for up to 80% of the total macrobenthos density. Meanwhile, bivalves （ （51.4 ± 7.8 ） g/m^2 ） and gastropods （ （38.7 ± 5.1 ） g/m^2 ） together accounted for more than 90% of the total biomass. On the other hand, there were significant differences in the distribution of macrobenthos among different north but low in the south. However, no significant difference was found in the density of macrobenthos groups between spring and autumn, except the density of bivalves in autumn was significantly higher than that in spring （P 〈0. 001 ）.