Distribution characteristics of benthic algae in rocky intertidal zones of Zhongjieshan Archipelago of Zhejiang Province in summer and autumn

We conducted a survey to study the species composition, distribution characteristics and temperature feature of the benthic algae in the rocky intertidal zones of Zhongjieshan Archipelago of Zhejiang Province in September 2006 and July 2007. Results show that 34 species are identified to belong to 3 phylums and 24 genera, among which 3 species of 3 genera belong to Phaeophyta, 5 species of 4 genera belong to Chlorophyta, and 26 species of 17 genera belong to Rhodophyta. Topical and selective distribution species influenced by wave and tide are identified in the intertidal zone. Sargassum thunbergii, Ulva pertusa and Corallina officinalis are mostly found in the survey area. Rhodophyta is the dominant species, with frequency of occurrence being 67.8%, and Phaeophyta shows a rather uniform horizontal distribution. 91.2% of the species are identified in low tide zone, showing an obvious vertical distribution of the species number: low tide zone mid tide zonehigh tide zone, and the absolute dominant species are sub-tropical ones.