春季我国不同纬度河口浮游动物群落变化趋势

Variation of zooplankton communities in Chinese estuaries along latitudes in spring

根据2010-2012年春季由南向北河口海域:北仑河口、九龙江口、瓯江口、长江口和灌河口的浮游动物调查资料,通过比较不同纬度河口浮游动物群落的生物多样性指数(H′)、物种更替率(R)和群落相似系数(S),探讨了河口浮游动物群落特征沿着不同纬度变化的趋势。结果表明,自南向北5个河口可以划分为3个不同的浮游动物区系。北仑河口和九龙江口为南部亚热带区系,位于亚热带海域,以亚热带种为主,H′分别为1.01和2.18,两河口之间R值为65.52%,S值为51.28%;瓯江口和长江口为中部过渡区系,位于亚热带和温带过渡海域,亚热带种和暖温带种是主要出现的种类,H′分别为1.31和1.86,两河口之间R值为58.33%,S值为58.82%;灌河口单独为北部温带区系,位于温带海域,暖温带种是主要出现的种类,H′值为1.19,与其余河口物种更替率均高于80.00%,群落相似系数均低于32.00%;表明群落结构由南到北的变化非常显著。线性回归结果表明:我国不同河口之间浮游动物的物种更替率与纬度差(两河口所处纬度的差值,ΔN)呈正相关关系(R=0.026ΔN+0.608,p=0.002);群落相似系数与纬度差呈负相关关系(S=0.034ΔN+0.578,p=0.001)。春季,我国不同纬度河口浮游动物群落结构的变化,主要是因为影响各河口的水温和水团存在较大差别所致。

Based on the zooplankton samples from stations in Beilun Estuary,Jiulongjiang Estuary,Oujiang Estuary,Changjiang Estuary（Yangtze River）and Guanhe Estuary（covering 14 latitudes）in April or May of 2010 to 2012,the community features of Diversity index（H′）,replacement rate（R）and similarity coefficient（S）were compared.This paper also analyzed the variation and reasons of zooplankton community in different estuaries.The results indicated that the zooplankton community of the five estuaries were divided into three different zooplankton fauna,which were the southern subtropical,central transitional and northern temperate from the south to the north.The southern subtropical zooplankton fauna included Beilun Estuary and Jiulong Estuary.In this fauna,the subtropical species was the mainly and a different diversity index（H′）（1.01 and 2.18）were recorded,located in the subtropical sea.There placement rate（R）and similarity coefficient（S）were respectively 65.52% and 51.28% between Beilun Estuary and Jiulong Estuary.In central transitional zooplankton fauna,constituted by Oujiang Estuary and Changjiang Estuary,it was exclusively of the subtropical species and warm temperate species,which had an alike diversity index（H′）（1.31 and 1.86,respectively）,situated in the transition waters between subtropical and temperate.Between the two estuaries,the replacement rate（R）were lowest（58.33%）and the similarity coefficient（S）were highest（58.82%）.At high latitude,only the Guanhe Estuary belongs to the northern temperate,the warm temperate species was dominated,which had a lower diversity index（H′）（1.19）and located in the temperate sea.The replacement rate（R）and similarity coefficient（S）of Guanhe Estuary were significantly different from the other estuaries.From south to north,along with the increase of latitude,the structure of estuarine zooplankton community has changed significantly.Linear regression figured that replacement rate（R）was positively correlated with the difference of longitude between the two estuaries in Chinese（ΔN）,R=0.026ΔN＋0.608（p=0.002）.Similarity coefficient（S）was negatively correlated with the difference of longitude（ΔN）,S=-0.034ΔN＋0.578（p=0.001）.In spring,the main reasons which caused the variation of zooplankton community between different estuaries was due to the difference of the influence of temperature and water masses.