舟山群岛东侧海域春秋季主要甲壳类物种的空间生态位分析

Analysis of the spatial niche of major crustacean species in the waters east of Zhoushan Islands in spring and autumn

生态位反映了物种资源利用的能力,揭示了物种的群落结构特征及环境适应性。为进一步了解舟山群岛东侧海域甲壳类种群的资源现状,根据2018年4月(春季)、10月(秋季)在该海域进行的拖网调查数据,运用相对重要性指数对该海域甲壳类物种优势度进行计测,基于Shannon指数及Pianka公式对主要甲壳类的生态位宽度及重叠情况进行了分析,并结合种间竞争系数与冗余分析(RDA)对生态位分化进行了研究。结果表明:(1)春、秋季主要甲壳类,即相对重要性指数(index of relative importance,IRI)>100的物种分别有11种、15种,其中春季优势种(IRI>1 000) 4种,秋季优势种5种。(2)春、秋季主要甲壳类生态位宽度分别为0.13~2.54和1.32~2.42,生态位宽度的季节差异较大,春季广生态位种(Bi≥2.0)仅口虾蛄(Oratosquilla oratoria)和日本蟳(Charybdis japonica) 2种,而秋季广生态位种有中华管鞭虾(Solenocera crassicornis)、口虾蛄、细巧仿对虾(Parapenaeopsis tenella)和三疣梭子蟹(Portunus trituberculatus)等8种。春季中生态位种(1.0≤Bi<2.0)有6种,秋季中生态位种有7种,而春季窄生态位种(0<Bi<1.00)仅须赤虾(Metapenaeopsis barbata)、日本英雄蟹(Achaeus japonicus)、假长缝拟对虾(Parapenaeus fissuroides)和绵蟹(Dromia dehaani) 4种,秋季无窄生态位种。(3)春季绵蟹和日本英雄蟹、秋季须赤虾和东海红虾(Plesionika izumiae)的空间生态位重叠值最大,表明种对在空间资源序列上的同域性最强,物种对空间资源的利用趋于一致。(4)春、秋季主要甲壳类空间生态位重叠显著(Qik>0.6)的种对所占比例均较低,总体上该海域主要甲壳类种间竞争关系较弱,生态位分化较明显。结合种间竞争系数和RDA结果,可进一步解释物种的种间关系及生态位分化情况。

Ecological niche reflects the resources utilization capability of species,reveals the community structure characteristics and environmental adaptability of species.Further,in order to understand the resource status of crustacean populations in the waters east of Zhoushan Islands,based on data of trawl survey of the area in April(spring)and October(autumn)in 2018,this study adopted the index of relative importance to measure the dominance of crustaceans in the waters,using Shannon index and Pianka formula to analyze the niche breadth and overlap of major crustacean species.It combined interspecific competition coefficient and redundancy analysis(RDA)to study niche differentiation.The results show that(1)There were 11 and 15 major crustacean species of which the index of relative importance(IRI)>100 in spring and autumn respectively,among which 4 were dominant species(IRI>1000)in spring and 5 in autumn.(2)The niche breadth of major crustacean species in spring and autumn were 0.13-2.54,1.32-2.42 respectively,niche breadth differed greatly between the two seasons.The wide niche species(Bi≥2.0)were only two species of Oratosquilla oratoria and Charybdis japonica in spring,while there were 8 species including Solenocera crassicornis,Oratosquilla oratoria,Parapenaeopsis tenella and Portunus trituberculatus in the autumn,the number of medium niche species(1.0≤Bi<2.0)was 6 in spring and 7 in autumn,and there were 4 narrow niche species(0<Bi<1.0)including Metapenaeopsis barbata,Achaeus japonicus,Parapenaeus fissuroides and Dromia dehaani in spring.(3)The spatial niche overlap between Dromia dehaani and Achaeus japonicus in spring,Metapenaeopsis barbata and Plesionika izumiae in autumn were highest,indicating that the spatial homology was high and the species’use of the spatial resources tends to be consistent.(4)The proportion of species pairs with significant spatial niche overlap(Qik>0.6)was low in spring and autumn,indicating that the competition among major crustacean species was weak and niche differentiation was obvious.Combining interspecific competition coefficient and redundancy analysis(RDA)results,we could further explain the inter-species relationship and niche differentiation of species.