渭河流域鱼类群落结构特征及其受环境因子的影响分析

本文以渭河流域为研究区,调查了全流域45个点位的鱼类群落和水环境理化特征,采用聚类分析确定渭河流域主要的鱼类群落分布类型,并运用典范对应分析方法(Canonical correspondence analysis,CCA)识别影响渭河流域鱼类群落结构的主要环境因子.本次鱼类调查共鉴定出鱼类36种,其中,鲤科和鳅科是构成渭河流域鱼类群落的主要类群.鱼类聚类结果显示,群落结构可分为3组,第1组主要分布在渭河源头及上游支流,鱼类以陕西高原鳅(Triplophysa shaanxiensis)、岷县高原鳅(Triplophysa minxianensis)为优势物种,包括拉式鱥(Phoxinus lagowskii)、北方花鳅(Cobitis granoei)等敏感物种,耐受物种分布极少;第2组主要分布在渭河上游和泾洛河上游,鱼类以达里湖高原鳅(Triplophysa dalaica)、背斑高原鳅(Triplophysa stoliczkae dorsonotata)、棒花鱼(Abbottina rivularis)为优势物种,包括少数拉式鱥等敏感种;第3组主要分布在渭河中下游,鱼类以泥鳅(Misgurnus anguillicaudatus)、马口鱼(Opsariichthys bidens)、麦穗鱼(Pseudorasbora parva)、棒花鱼和鲫(Carassius auratus)等江河平原鱼类为主,耐受物种较多.CCA分析结果显示,影响渭河流域的主要环境因子有海拔高度、溶解氧含量、流速、高锰酸盐指数、砂/淤泥/粘土所占比例和草地所占比例.而对于不同的指示物种,影响其分布的主要环境因子也各有不同.本研究是继20世纪80年代以来首次对渭河全流域进行水生态调查,并分析渭河流域鱼类的群落结构特征,可为流域水生态系统恢复提供重要的科学依据.

Fish community structure and the effect of environmental factors in the Wei River basin

Fish community and water environmental factors at 45 sampling sites were investigated in this study. Fish community distribution were examined by cluster analysis, and Canonical Correspondence Analysis (CCA) was used to distinguish the primary environmental factors that affected the fish community structure. Thirty-six species were collected in the Wei River basin, and Cyprinidae and Cobitidae were the main fish community structure in the Wei River basin. Three groups of fish community were distinguished by the cluster analysis. Distributed in the head water and tributaries in the upstream, the first group is dominated by Triplophysa shaanxiensis and Triplophysa minxianensis, and includes sensitive species, such as Phoxinus lagowskii and Cobitis granoei. The second group is in the upstream of the Wei River and Jing River, and is dominated by Triplophysa dalaica, Triplophysa stoliczkae dorsonotata and Abbottina rivularis, with inclusion of several sensitive species such as Phoxinus lagowskii. The last group is in the plain rivers with intensive human activities, most located in the Guanzhong district. It is dominated by Misgurnus anguillicaudatus, Opsariichthys bidens, Pseudorasbora parva, Abbottina rivularis and Carassius auratus, and many tolerant species were found in this group. Thirty-one environmental factors in five categories were analyzed by CCA. The results showed that altitude (Altt), dissolved oxygen (DO), velocity, COD_Mn, percentage of sand/silt/clay and percentage of grassland area are primary environmental factors that affect fish community in the whole basin. The primary environmental factors affecting the indicator species are different. This is the first study to investigate fish community structure in the Wei River basin since the 1980s. It provides an important reference for the restoration of watershed ecosystem in the Wei River basin.