Effects of Spartina alterniflora invasion on distribution of Moerella iridescens in a tidal flat of Western Pacific Ocean

The invasion of Spartina alterniflora significantly affected the local ecosystem of Western Pacific Ocean where Moerella iridescens lives. Five patches with different invasion stages of S. alterniflora were selected and the influence on distribution of M. iridescens was studied on the coast of Wenzhou Bay, China in ۲۰۰۷. The aggregated distribution pattern was proved by using Taylor;#۳۹s power regression and Iwao;#۳۹s plot regression methods (p<۰.۰۰۱). The densities were significantly affected by the factors of S. alterniflora invasion stage and season (p<۰.۰۰۱), but no significant effect of interaction (p=۰.۸۰۵) occurred. M. iridescens mainly clumped in the habitats of no invasion and initial invasion of S. alterniflora was in the high tidal zone, and the lowest density was recorded where complete invasion occurred. The densities were larger in warmer than in cooler seasons. There were significant positive correlations among the average densities in seasons. Density variation must be the response of M. iridescens to the environment, including S. alterniflora invasion stage, temperate stress and interspecific associations.

Keywords:

Coastal wetland , Distribution pattern , Habitats , Lingkun Island