洞头列岛潮间带大型底栖生物的时空分布及其多样性

摘要

In this paper, 4 sections in Dongtou Archipelago were chosen to investigate the spatial-temporal distribution and the biodiversity of intertidal macrobenthos in autumn (Oct.) 2006 and spring (Apr.) 2007, respectively. The total number of macrobenthos in four sampling sites was 72, which included 44 species of mollusc, 13 species of crustacean, 11 species of macro algae, 2 species of polychetes, 1 species of echinoderm, and 1 species of the other group. Compared with the data in autumn and in spring, the number of species in the former (66 species) was slightly higher than that in latter (63 species), whereas the average biomass and abundance in the former (576.98 g/m2,461 ind/m2) were obviously lower than that in latter (1 129.23 g/m2,707 ind/m2). For all of the sections, Thais clavigera Kuster, Tetraclita japonica Pilsbry, Tectarius granularis Gray, were the dominant species and accounted for over 60% of the whole biomass and abundance. For the average index of biodiversity, the species biodiversity index was 1.73 ± 0.47(0.83-2.10), the index of Margalef's species richness was 2.26 ±0.33(1.99-2.95), the Pielou's evenness was 0.62 ±0.19(0.29-0.85), and the index of Simpson's dominance was 0.70 ± 0.18(0.36-0.87). The whole result indicated human activities were the main factor to lead to the extremely unstable community in the intertidal macrobenthos with the lower biodiversity in Dongtou Archipelago. And there was a trend of evolving into the secondary type community structure.%为了解洞头列岛潮间带大型底栖生物的时空分布特征及其多样性,分别于2006年秋季(10月)和2007年春季(4月)对洞头列岛4个断面开展了春秋航次调查.共鉴定出大型底栖生物72种,包括软体动物44种,甲壳动物13种,藻类11种,多毛类2种,棘皮动物1种,其它动物1种.从季节来看,虽秋季航次的物种数(66种)稍高于春季(63种),但平均生物量和丰度却都是春季航次(分别为1 129.23 g/m2、707 ind/m2)明显高于秋季航次(分别为576.98 g/m2、461 ind/m2).各断面主要优势种为疣荔枝螺、日本笠藤壶和粒屋顶螺等,它们占总生物量和丰度的60％以上.从多样性指数来看,洞头列岛物种多样性指数平均为1.73±0.47,变化范围为0.83～2.10,物种丰富度指数平均为2.26±0.33,变化范围为1.99～2.95,均匀度指数平均为0.62±0.19,变化范围为0.29～0.85,辛普森优势度指数平均为0.70±0.18,变化范围为0.36～0.87.综合以上结果发现,洞头列岛各断面潮间带大型底栖生物群落结构不稳定,且物种多样性较差,有向次生型群落结构演化的趋势,主要原因是过度采捕、生境破碎等人为干扰过于严重导致的.