中文摘要：

在对长江口崇明、长兴、横沙和九段沙四个冲积岛屿的野外调查和标本鉴定基础上,记录报道苔藓植物16科28属50种.崇明岛种类最为丰富,有15科24属42种;长兴岛、横沙岛次之,分别有5科10属18种和6科11属17种;九段沙最少,仅有3科4属4种.分析结果表明：长江口诸岛苔藓植物生境以土生为主,植物地理区系成分以北温带及东亚成分占多数,其中中国特有成分4种.大部分苔藓植物为常见的随人种类,人类活动是影响长江口诸岛苔藓植物物种多样性的主要因素之一.长江口各岛屿的苔藓植物物种多样性与岛屿形成时间、岛屿面积之间存在密切关系,反映了河口沙洲环境的总体特征.

英文摘要：

Based on the field investigation and identification of the specimens collected, 50 species belonging to 16 families and 28 genera of bryophytes on four alluvial islands in the Estuary of Yangtze River are reported. The bryo - diversity of Chongming Island with 15 families, 24 genera,42 species is the highest; Changxing and Hengsha are second, with 5 families, 10 genera,18 species and 6 families, 11genera, 17 species, respectively. The lowest one is Jiuduansha Islands with only 3 families, 4 genera and 4 species. Most species on the islands grow on soil habitat. Floristie analysis showed that North Temperate elements and East Asian elements are dominant in this region. Four Chinese endemic species are recorded on these islands. Most bryophyte species are common ones in Shanghai and East China, and human disturbances may be one of the main factors which influences the bryological biodiversity of the islands in the Yangtze River Estuary. There are distinct relationships between species diversity of bryophytes and the area and formation time of the islands.