The temporal and spatial distributions of the macrobenthos in Spartina alterniflora salt marsh

Spartina alterniflora Loisel was introduced from USA to China and it is a new adventitious species of plant to Chinese environment.This plant that covers a vast area between mean sea level and mean high level has become a dominant plant on tidal flats.Four sampling sites were selected outside the Badou reclamation area where the Spartina alterniflora Loisel grew well,and the macrobenthos sampling was collected at different depths in four seasons,and then the temporal and spatial distributions of the macrobenthos in Spartina alterniflora salt marsh were analyzed by using the methods of sieving,fixation,identification and calculation of the community indicators.The result shows that there are 4 phylums,5 classes,12 families and 15 species of macrobenthos in Spartina alterniflora loisel salt marshes,and the Batillaria zonalis Bruguiere and Lunatis gilva Philippi are the dominant animals,accounting for 34.91% and 32.23% respectively.The macrobentho animal species have a greater seasonal difference in the number of individuals,the highest in summer and lowest in autumn.The community indicators have no significant variation with the change of seasons.In terms of spatial distribution,the largest average number of macrobenthos individuals is observed at points H2 where the Spartina alterniflora loisel grows well,and the smallest is found at point H4 with no gross covered,and some macrobenthos,such as Batillaria zonalis Bruguiere and Perinereis aibuhitensis Grube are observed at all the points,showing that this plant has a wide habitat.As for vertical distribution,the upper layers have the largest amount of macrobenthos in all the seasons and at all the sampling sites.