黄河口水域主要鱼种的时空生态位宽度和重叠

Width and overlap of spatial and temporal ecological niches for main fish species in the Yellow River estuary

生态位在研究群落结构、种间关系和生物多样性等方面具有重要作用。为深入了解黄河口水域鱼类群落结构和种间关系,本研究根据2013—2014年在黄河口水域进行的7个航次的渔业资源底拖网调查数据,应用平均拥挤度、生态位宽度和生态位重叠值等指数研究了该水域12种鱼类的时空生态位宽度和重叠特征。结果表明,黄河口水域主要鱼种时间生态位宽度变化范围为0~1.53,其中矛尾虾虎鱼(Chaemrichthys stigmatias)和方氏云鳚(Enedrias fangi)时间生态位宽度值较高,安氏新银鱼(Neosalanx anderssoni)和鮻(Liza haematocheila)较低。主要鱼种空间生态位宽度具有明显季节变化。所有鱼种间的平均空间生态位重叠值也有着明显的季节差异。生态位宽度和重叠值与各鱼种数量、分布、生态习性和生境状况密切相关,反映了该海域不同鱼种对生境资源的不同利用能力。

“Ecological niche”refers to the sum of the physical space,functional status,and environmental requirements occupied by species in a community.The ecological niche plays an important role in studies on community structure,interspecific relationships,and biodiversity.Based on data collected from the bottom trawl surveys in 2013–2014 in the Yellow River estuary,the spatio-temporal niche width and overlap for 12 fish species were examined using the mean crowding,niche width,and niche overlap indices.The temporal niche width indices for main fish species ranged from 0 to 1.53,which were relatively high for Chaemrichthys stigmatias and Enedrias fangi and relatively low for Neosalanx anderssoni and Liza haematocheila.The spatial niche breadth of the main fish species varied with season,and it was high in winter for Neosalanx anderssoni,Acanthogobius ommaturus,and Liza haematocheila and low in summer for Konosirus punctatus and Thrissa kammalensis.The temporal niche overlap indices among main fish species ranged between 0 and 1,and 11 species pairs reached significant ecological niche overlap.Thirty-two species pairs had low temporal overlap,occupying 46.48%of the total species pairs.This showed that the main fish species were not similarly distributed in time.Clear seasonal changes in the spatial niche overlap indices were observed for fish pairs.The spatial niche overlap indices between Cynoglossus joyneri and C.stigmatias ranged from 0.22 to 0.86,and were high in summer and autumn and low in winter.The mean spatial niche overlap indices for all species pairs varied between seasons,they were highest in autumn at 0.17,followed by summer(0.11–0.14)and spring(0.07–0.13)and were the lowest in winter(0.07).Cluster analysis showed that all the species pairs could be divided into five groups in terms of spatial niche overlap,with relatively high niche overlap among species pairs in each group.Niche breadth and overlap for fish species was strongly related to species abundance,spatial distribution,ecological habit,and habitat conditions,which revealed the different abilities of species to effectively utilize the environmental resources in the Yellow River estuary.