基于多元统计分析的渔山列岛潮间带软体动物功能群和次级生产力比较

THE SECONDARY PRODUCTIVITY OF MOLLUSK IN THE INTERTIDAL ZONE OF YUSHAN ISLANDS AND COMPARATION STUDY BASED ON MULTIVARIATE STATISTICAL ANALYSIS

渔山列岛于2008年成为国家级海洋生态保护区,为了解渔山列岛保护区内潮间带软体动物次级生产力的时空变化。于1982年和2010年的3个季节(春、夏、冬)在渔山列岛进行潮间带软体动物调查,采用多元统计分析软体动物时空差异,以Brey经验公式计算分析软体动物次级生产力(P值,P/B值)。结果表明,年际间物种食性结构发生了明显的改变,1982年潮间带软体动物对次级生产力贡献率最大的物种有单齿螺(Monodonta labio)、锈凹螺(Chlorostoma rustica),占软体动物总次级生产力的42.88%,2010年潮间带软体动物对次级生产力贡献率最大的物种有覆瓦小蛇螺(Serpulorbis imbricata)、条纹隔贻贝(Septifer virgatus),占软体动物总次级生产力的75.96%。1982年,年均栖息密度为2758ind/m2,年均生物量为2100.26g/m2,年均次级生产力为240.04g/(m2·a),年均P/B值为0.63a–1;2010年,年均栖息密度为699ind/m2,年均生物量为1101.85g/m2,年均次级生产力为94.82g/(m2·a),年均P/B值为0.55a–1。多因素方差分析表明软体动物次级生产力年际间差异显著(F=5.761,P<0.05),季节间和潮位间差异都不显著(F=0.135,P>0.05;F=2.076,P>0.05),P/B的值较低,表明该海域软体动物世代更替速度较慢,2010年的P/B值(0.55a–1)低于1982年的P/B值(0.63a–1),表明近30年来群落结构受到影响。

Yushan Islands, East China Sea, is a national marine ecological protection zone established in 2008. To understand temporal and spatial changes in secondary productivity of mollusks in the intertidal zone of the protection area, we conducted investigations at intertidal mollusks in the area in 1982 and 2010 in spring, summer, and winter. Multivariate statistical analysis was used to reveal temporal and spatial differences of mollusks, and the Brey empirical formula was adapted to analyze the secondary（P value, P/B value） productivity. The results show that the species structure of food habit changed significantly. In 1982, the species of the highest contribution rate to the secondary productivity were Monodonta labio and Chlorostoma rustica, taking 42.88% of the total. In 2010, the highest contributors were Serpulorbis imbricateand Septifer virgatus, taking 75.96% of the total. The annual average values were, in 1982： density 2758ind/m2, biomass 2100.26g/m2, secondary productivity 240.04g/（m2·a）, and P/B 0.63a–1; in 2010, they were 699ind/m2, 1101.85g/m2, 94.82g/（m2·a）, and 0.55a–1, respectively. In addition, result of multivariate analysis of variance shows that the interannual secondary productivity of mollusks varied significantly（F=5.761, P〈0.05）, but not in season and in tidal space（F=0.13, P〉0.05; F=2.076, P〉0.05）. The small P/B ratios indicate that the sea mollusks generation replacement was slow, and slower in 2010（0.55a–1） than in 1982（0.63a–1）, indicating that the community structure became worsened in the past nearly 30 years.