浙南潮间带大型底栖藻类时空分布及多样性研究

Study on spatiotemporal distribution of intertidal benthic macro-algae and their diversity in southern Zhejiang Province

在浙南地区布设10条断面开展春秋航次潮间带大型底栖藻类调查,重点对大型底栖藻类的时空分布及多样性进行研究。共鉴定出大型底栖藻类61种,其中包括绿藻门8种,褐藻门16种,红藻门36种,蓝藻门1种,区系特征明显,大型底栖藻类的季节演替也非常明显,春季的物种数(53种)明显高于秋季(25种),而两个季节都出现的物种只有17种。浙南大型底栖藻类平均生物量为540.16g·m-2,春季(722.18g·m-2)明显高于秋季(358.14g·m-2);从垂直分布来看,秋季与春季各断面生物量也并不相同,秋季低潮区739.45g·m-2>中潮区334.95g·m-2>高潮区0g·m-2;春季中潮区1 943.30g·m-2>低潮区965.03 g·m-2>高潮区290.41g·m-2。从物种优势度可以看出,两个季节的主要优势种有相同之处,但它们在群落的功能地位上随着季节有着较大的变化,如春季鼠尾藻Sargassum thun-bergii(Mert.)O.Kuntze是第1优势种,而秋季却成第2优势种。Shannon-Winner指数(H′)、Margalef物种丰富度指数(d)和Pielou均匀度指数(J′)的平均值秋季分别为1.38±0.66、0.70±0.38、0.93±0.41,春季分别为1.65±1.09、1.07±0.63、0.80±0.38。各断面多样性相差较大,这与浙南各断面的大型底栖藻类的稳定和复杂性有很大关系,这一点从群落结构聚类分析也得到验证。

The authors investigated the spatiotemporal distribution of intertidal benthic macro-algae and their diversity in 10 sections of southern Zhejiang province in autumn 2006 and spring 2007. The results showed that 61 species of benthic macro-algae were collected, including eight Chlorophyta, 16 Phaeophyta, 36 Rhodophyta and one Cyanophyta. Flora charac- teristic of the benthic alga distribution was very obvious in the inter-tide of southern Zhejiang, and it also changed obviously with seasons in species composition and biomass of benthic algae. More species were found in spring （53 species） than in autumn （25 species）, among which only 17 species existed in both of these two seasons. The average biomass of intertidal benthic marco-algae was 540.16g.m-2 in southern Zhejiang, and there was more biomass in spring （722.18g.m-2） than in au- tumn （358.14g.m-2）. As for the vertical distribution of biomass, it was also different in the 10 sections during the two seasons. In autumn, the biomass of intertidal benthic marco-algae was in the order of low intertidal zone （739.45g.m-2）〉 middle inter- tidal zone （334.95g.m-2）〉 high intertidal zone （0g.m-2）; in spring it was sequenced as middle intertidal zone （1 943.30g.m-2）〉 low intertidal （965.03g.m-2） 〉 high intertidal zone （290.41g.m 2）. There was something in common for the dominant species in the two seasons in terms of dominance, but their functions in the community changed greatly with seasons. For example, Sar- gassum thunbergii （Mert.） O. Kuntze was the first dominant species in spring, but it was the second in autumn. The averages of Shannon-winner index, Margalef＇s species richness index and Pielou＇s evenness index were 1.38±0.66, 0.70±0.38 and 0.93±0.41 in autumn, and 1.65±1.09, 1.07±0.63, 0.80±0.38 in spring, respectively. There was great difference in diversity of benthic marco-algae among sections, which was related to the stability and complexity of benthic marco-algae in southern Zhejiang, as certified by the cluster analysis.