岩相潮间带大型底栖生物多样性对铜藻藻场的响应

Response of macrobenthos diversity to seaweed bed of Sargassum horneri in the rocky intertidal zone of Nanji Islands

2011年4月至2012年1月间,在南麂列岛火焜岙铜藻藻场和藻场外沿岸潮间带各设1条断面,对大型底栖生物的种类和数量组成、物种多样性和群落结构特点进行调查。共鉴定出底栖生物108种,其中,底栖动物93种,底栖藻类15种;藻场与藻场外沿岸高潮区和中潮区的软体动物、节肢动物、环节动物、其他动物和藻类的年均生物量和丰度均无显著差异;低潮区藻场沿岸藻类生物量大于藻场外沿岸,其他类群的年均生物量和丰度无显著差异。每个季节各潮区除春季低潮区藻场沿岸的藻类生物量大于藻场外沿岸外,其他均无显著差异。藻场沿岸潮间带的优势种为条纹隔贻贝,藻场外沿岸为条纹隔贻贝和棘刺牡蛎。藻场沿岸和藻场外沿岸潮间带大型底栖生物的Shannon-Wiener指数(H'),Pielou均匀度指数(J)和Margalef丰富度指数(d)无显著差异(P>0.05)。非度量多维标度(MDS)和聚类分析表明,群落结构主要与季节有关,但在铜藻藻场生长旺盛期与藻场有关,说明铜藻生长旺盛期对其群落结构有一定的影响。

From April 2011 to January 2012, we set one section in intertidal zones respectively in seaweedbed coast of Sargassum horneri and out-seaweed bed coast of Huokun ＇ ao, Nanji islands, and surveyed thespecies and amount of intertidal macrobenthos, species biodiversity and the characteristics of communitystructure. In this survey, we totally identified 108 species, including 93 species of macrozoobenthos and 15species of benthic macroalgae. The annual average biomass and abundance of mollusks, arthropods,polychetes, other,animals and algae were not significantly different in seaweed bed and out-seaweed bedcoast. There was no significant difference in annual average biomass and abundance of mollusks, arthropods,polychetes, other animals and algae of the two sections in high tidal zone and middle tidal zone, but in lowtidal zone, the algae biomass of the seaweed bed coast was higher than that of the out-seaweed bed coast, thebiomass and abundance of other groups had no significant difference. There was no significant difference in allseasons and all tidal zones in seaweed bed and out-seaweed bed coast, except spring, in which the algaebiomass of low tidal zone in seaweed bed coast was higher than that in out-seaweed bed coast. The dominantspecies of intertidal in seaweed bed coast was Septifer virgatus, in out-seaweed bed coast were Septifer virgatusand Saccostrea echinata. There was no significant difference （ P 〉 0.05 ） in Shannon-Wiener （ H ＇）, Pielou（J） and the Margalef （d） in seaweed bed and out-seaweed bed coast. Nonmetric multidimensional scaling（MDS） and cluster analysis showed that the community structure was mainly related with seasons, but duringthe period when Sargassum horneri grew exuberantly, it was related with the seaweed bed, which suggestedthat the exuberant growth period of Sargassum horneri would affect the community structure.