温州湾春季主要游泳动物生态位与种间联结性

摘要

According to the fishery resources survey data of Wenzhou Bay in Spring 2013 (May) and Spring 2014 (May),we used spatial niche breadth and overlap to determine the major niches of nekton.A series of methods,including the variance ratio (VR) method,x2 test,the association coefficient (AC),percentage of co-occurrence (PC),and functional group classification and trophic level constituents combined the means of niches were used to analyze the relationships among the major marine nekton species.The results showed that there were 18 major nekton species.The three dominant species were Amblychaeturichthys hexanema,Harpodon nehereus,and Pampus argenteus,which had large spatial niches.The other 15 species were main species.In general,there were large differences in the niche overlap values among the major nekton populations,with a maximum value of 0.88 and a minimum of 0.01,indicating a possible resource utilization competition among some nekton species.The VR value was greater than 1 at 9.90,and the W value was 366.39,which was considerably greater than the confidence interval (8.67,27.59).There were significantly positive correlations between the major nekton community species.The percentage co-occurrence of species showed that only three pairs had strong positive association,and no unrelated species pairs was revealed,have not unrelated species pairs.The coupling coefficient showed that 110 pairs of species tended to be independent,indicating that species were independent distributions.According to the type of feeding,the major nekton species could be divided into 5 functional groups:the planktophagous group (Pl),the phytophagous group (Ph),the carnivorous group (C),the omnivorous group (O),and the detritivorous group (D).In terms of percentages of the total nekton,these groups could be ordered as follows:C ＞ O =P1 ＞ D ＞ Ph.Based on the relationship among the functional groups,the trophic levels for major nekton species varied from the second to fourth trophic levels,the third and fourth trophic levels were the major trophic leves in our study.A complex food web is formed between each trophic level.%根据2013年春季(5月)与2014年春季(5月)在温州湾海域两次渔业资源调查的数据,运用生态位宽度、聚类分析、生态位重叠值、方差比率法、卡方检验、联结系数及功能群划分和营养级构成等方法相结合对主要游泳动物群落物种间的相互关系进行综合分析.结果表明:主要游泳动物共18种,优势种为六丝钝尾鰕虎鱼(Amblychaeturichthys hexanema)、龙头鱼(Harpodon nehereus)及银鲳(Pampus argenteus),其他15种是重要种;生态位重叠值最大值和最小值分别为0.88和0.01,总体差异性较大,部分种对间对生态利用可能存在一定竞争性;由VR值为9.90大于1,W值为366.39远超出置信区间(8.67,27.59),得知游泳动物群落总体上呈显著正相关;共同出现百分率显示强正联结的种对仅3对,不存在无关联种对,但联结系数值显示110对种对趋向独立,说明种对间具有相对独立分布的特性;按食性类型可把主要游泳动物划分成5个功能群,依次是肉食者(C)、杂食者(O)、植食者(Ph)、浮游生物食者(Pl)和碎屑食者(D),各功能群所含物种种类数百分比由高到低依次是C＞O=Pl＞D＞Ph,依据功能群间的关系得出主要游泳动物占据二、三、四级营养级,集中分布于三、四营养级.