Community Characteristics Of Macrobenthos In The Intertidal Zone Along The Coast Of The Yanpu Bay After Kandelia Candel Planting

In this paper,based on the survey data of the macrobenthos living in the intertidal belt before planting the Kandelia candel forest in October 2014(Autumn)and March 2015(Spring)along with the Yanpu Bay of Cangnan County and after its planting in October 2016(Autumn),December 2016(Winter),March 2017(Spring)and June 2017(Summer),the species diversity index,G-F diversity index,ABC curves and other method are applied to analyze the change of the macrobenthos community structure before and after planting the Kandelia candel.50 kinds of macrobenthos are identified in the four seasons after planting Kandelia candel forest,subordinate to 6 classes,14 orders,29 families and 38 categories.The change of species number is as follows: autumn >summer>spring> winter,there is obvious succession phenomenon between dominant species and important species.It is analyzed from the intersection of the richness curve and biomass curve in the ABC curves to obtain that it is influenced by moderate environmental pollution and artificial disturbance in autumn and spring,and it is influenced by relatively serious environmental pollution and artificial disturbance in winter and summer.CCA ordering results show that the first ordination axis has the maximum positive correlation with cadmium(0.3899)and has positive correlation with petroleums,it gradually increases on the ordination axis from left to right.And the second ordination axis has the maximum positive correlation with cadmium(0.4911),namely,it gradually increases from bottom to up.The functional groups in the intertidal belt of the Yanpu Bay are the 4 kinds of functional feeding groups in four seasons,showing the stability of the community structure.The functional feeding groups of the phytophagy and plankton account for the maximum.There are the major two routes for the materials cycle and energy flow of the food chain below:(1)plant ?phytophagy ?omnivory ?sarcophagy;(2)plankton ?plankton feeding habit ?omnivory ?sarcophagy.Through the comparison in the Kandelia candel forest before and after planting,it can be seen that after planting,there is an obvious growth in the density and biomass of the Kandelia candel during spring and autumn in the high tide belt of the its planting area,and the community diversity obtains overall improvement through the species diversity index and G-F diversity index.The serious interference of the macrobenthos community in autumn is improved to moderate degree after planting relative to the one before planting Kandelia candel.Excepting for that the macrobenthos community has similar characteristics with the autumn one in the moderate tide belt,the interfered degree of the community in the high tide belt of spring is improved obviously,while the interfered degree of the community in the low tide belt is slightly improved.The marine ecosystem of mud flat is improved better,therefore,local government and its competent authorities are recommended to increase its input to further strengthen the construction of Kandelia candel in Yanpu Bay.At the same time,the government should reinforce law enforcing management to strictly prohibit all artificial development activities seriously damaging ecological environment.