莱州湾鱼类群落的关键种

Keystone species of fish community in the Laizhou Bay

关键种对群落结构稳定性起着决定作用,它的筛选对于整个生态系统的研究都具有重要的理论和实际意义。本研究基于2011年5月对莱州湾渔业底拖网数据,以摄食关系为基础构建了莱州湾鱼类群落种间相互作用关系网,运用网络分析法计算了该关系网的13种重要性指数及Key Player Problem参数(F、DF和DR)。根据13种指数的排序结果、聚类信息和3个Key Player Problem参数,对莱州湾鱼类群落的关键种进行了筛选。结果显示,13种重要性指数可划分为4个信息组:a(D、CC、IC、TI^1和TI^7)即基本信息组、b(D_(in)、H_(in)和K_t)即信息输入组、c(D_(out)、H_(out)和K_b)即信息输出组和d(BC和K)即信息控制组。细纹狮子鱼(D、D_(in)、BC、CC、IC、H_(in)、TI^1、TI^7、K、K_t、F、~DF和~DR)和六丝矛尾虾虎鱼(D_(out)、H_(out)和K_b)在莱州湾鱼类群落的网络分析结果中处于最高地位,密切联系着群落的其他种群,控制着群落的结构和能流,属于群落的关键种,其中细纹狮子鱼是关键捕食者,控制着群落中其他重要食物竞争者和捕食者密度,六丝矛尾虾虎鱼是关键被捕食者,通过维持捕食者的密度来限制其他被捕食者的密度。

Keystone species play a decisive role in community structure and stability, and the key species study has both important theoretical and practical significance for the entire ecosystem. In this paper, we tried to screen out the fishery key species from the fish community in the Laizhou Bay based on the bottom trawl survey data in May,2011. Firstly, we established a relationship network of the 24 fish species according to the predation relationships among fish populations. Then 13 network important indices were calculated using the Ucinet 6 and Co SBi Lab Graph1.0 software. A hierarchical clustering was conducted to show the relationships between 13 network indices,and 3 Key Player Problem parameters were calculated using keyplayer1.44 programme. The result showed these13 indices can be divided into 4 different information groups： a（D, CC, IC, TI1 and TI7）, basic information group; b（Din, Hin and Kt）, input information group; c（D_（out）, H_（out） and K_b）, output information group; d（BC and K）, control information group. The species were identified as the key species based on the information of 13 indices and 3 Key Player Problem parameters. Liparis tanakae（D, Din, BC, CC, IC, Hin, TI^1, TI^7, K, Kt, F, ~DF and ~DF） and Amblychaeturichthys hexanema（D_（out）, H_（out） and K_b） had the highest rank among the 24 study species, and closely tied to others in the fish community, controlled the structure and energy flow of the community, indicating that they were the key species in fish community in the Layzhou Bay. And L. tanakae was the key predator which could control the density of the predators and other competitors in fish community while A. hexanema was the key prey which could restrict the density of other prey species by maintaining the density of the predator.