杭州湾南岸大桥建设区域潮间带大型底栖动物功能群及营养等级的季节动态

2006年5月至2007年1月在杭州湾南岸跨海大桥附近潮滩共采集到32种大型底栖动物,根据其食性类型划分为5种功能群。用功能群方法对这些物种生境变化的关系进行了分析,结果表明:大型底栖动物各多样性指数在潮带间差异显著,季节间则只有Margalef种类丰度(S)和Shannon-Wiener指数(H′)存在显著性差异;各功能群密度在季节间均不存在显著性差异,而在潮带间除了浮游生物食者外,其它类群均存在显著性差异;肉食者的种类数在潮带间不存在显著性差异,而在季节间存在显著性差异,其它功能群刚好相反。滩涂大型底栖动物群落主要包括4个营养级别,各营养级的构成密度在季节间差异不显著,在潮带间则差异显著;各营养级种类数是处于第四级的肉食者季节间差异显著,潮带间变化不显著,处于第二、三营养等级的功能群则正好相反。底栖动物功能群多样性综合反映了杭州湾南岸大桥建设区域潮间带大型底栖动物群落变化情况。

Seasonal dynamics of macrobenthic functional groups and trophic levels in the bridge construction zone at the South Bank of Hangzhou Bay, China

A survey (May 2006 to February 2007) was carried out on the tidal flat near the Hangzhou Bay Sea-Crossing Bridge at the south bank, in order to assess the changes in habitat conditions of the tidal flat wetland resulting from differences in the zoobenthic community structure and function on different tidal flats and in different seasons. Macro-invertebrates were identified and counted. Based on the data collected from samplings near the bridge at the south bank of the Hangzhou Bay, we have categorized functional groups according to feeding types. 32 species were identified, and assigned to 5 distinct functional groups (planktophagous, phytophagous, carnivorous, omnivorous and detritivorous) and 4 trophic levels. The results showed that all the zoobenthic community's diversity indices referred to in this paper were significantly different between the tidal flats, while only Margalef's species richness indexes and the Shannon-Wiener diversity coefficient showed a significant difference between seasons. There was no significant difference between seasons for any of the diversity indices of functional group density, but a significant difference was found between the tidal flats (except for the planktophagous group). The number of species in the carnivorous group showed no significant difference between tidal flats, while a significant difference was found between seasons, as opposed to the other functional groups. There was no significant difference between seasons for any of trophic levels density, but a significant difference was found between the tidal flats. The number of species placed in the carnivorous group showed a significant seasonal difference, while no significant difference between tidal flats, as opposed to the other functional groups which placed in the second and third trophic levels. This study suggests that basic zoobenthic community parameters were reflected in the composition and diversity of the functional groups. Obtaining species diversity information from the analysis of the composition and diversity of functional groups helps us to understand changes in the ecological relationships underlying complicated community changes.