渤海线虫群落的多样性及中性模型分析

Biodiversity and neutral model analyses on nematode community in Bohai Sea, China

对渤海的黄河口水下三角洲、莱州湾和渤海中部共 9个站位的海洋线虫群落的多样性进行了研究。用于比较的海域和站位还包括 1 995年胶州湾的 95 B2站和 1 988年湄州湾的 A0 1站。以上 1 1个站位共鉴定出自由生活海洋线虫 1 5 4种 ,分属于 1 0 7属 2 9个科。使用种丰度 (SR) ,香农 -维弗指数 (H′)和均衡度 (J)用来比较不同生境的生物多样性。不同生境和站位的生物多样性水平由高到低依次为 :渤海中部 (9761、DA1 8、DA1 9和 DA2 0 ,SR=8.60± 0 .84 ,H′=4 .94±0 .2 3 )、莱州湾 (9762、DA2和 DA4 ,SR=6.4 8± 0 .4 0 ,H′=3 .95± 3 .0 )和黄河口水下三角洲 (E9和 E1 1 ,SR=4 .1 8±0 .5 6,H′=3 .60± 0 .2 4 )。线虫生物多样性与海水的盐度和沉积物的异质性指数 (h)呈显著的负相关 (P≤ 0 .0 1 )。Caswell中性模型分析指明 ,大部分研究站位的“V”值为“-2～ +2”,说明未受到显著外界因子的扰动。渤海中部的 9761站的“V”值为 2 .0 5 4 ,暗示环境稳定性的增强 ,而莱州湾的 DA4站“V”值为 -2 .62 4指明受到外界环境因子的显著影响 。

The biodiversity analysis for free living marine nematodes was made based on two stations sampled in 1997, together with the data collected from 7 stations in 1986, one station from Jiaozhou Bay in 1995 and the other from Meizhou Bay in 1988. Total of 154 species belonging to 107 genera and 29 families were identified from the data collected from eleven stations. Species richness ( SR ), Shannon winner index (H ′), equitability ( J ) were used to measure and compare the biodiversity. The sequence of biodiversity level in different habitats and stations from high to low is as follow: central part of Bohai Sea (9761, DA18, DA19 and DA20, SR =8 60±0 84, H ′=4 94±0 23)>Laizhou Bay stations ( 9762, DA2 and DA4, SR =6 48±0 40, H ′=3 95±3 0)>subaquatic delta stations (E9 and E11, SR =4 18±0 56, H ′=3 60±0 24). Biodiversity index of nematode were negatively related to salinity and heterogeneity ( P ≤0 01). Caswell ‘neutral model' analysis indicates that the V statistic for Bohai Sea was between “-2 ～ +2” in all but 2 cases. The positive V statistic of 2 054 in 9761 means the enhancement of environmental stability and negative V statistic of -2 624 in DA4 shows significant disturbance from runoff from Yellow River Estuary.