Abstract: Medog is rich in plant species due to its special geographical location and huge elevation difference. Its unique physical geography and climatic conditions give birth to a variety of habitats for the distribution of bryophytes and form a diverse bryophyte community. In order to study the bryophyte diversity and its life-form composition in Medog of Xizang, line collection methods was used to investigate and collect bryophyte specimens, species identification and correlation analysis. The results showed that: (1) the present checklist includes 631 species belonging to 239 genera in 83 families, with 2 hornwort species in 2 genera and 2 families, 217 liverwort species in 68 genera and 38 families, and 412 moss species in 169 genera and 43 families. There are 19 dominant families, 26 dominant genus and 19 dominant species of bryophytes in this area. (2) There are 327 species belonging to Soil and Rock-community, accounting for 51.83% of the total bryophytes species in Medog; There are 216 species belonging to Rock-community, accounting for 34.23% of the total bryophytes species in the area; there are 173 species in Soil-community, accounting for 27.42% of the total bryophytes species. There are 97 species in Tree-community, accounting for 15.37% of the total bryophytes species in this area, and 21 species in Leaf epiphyte-community, accounting for 3.32% of the total bryophytes species in this area. Overall, because of its good natural environment conditions, Medog provides good conditions for the survival of rich bryophytes.

Key words: bryophytes, species diversity, community characteristics, life form, Medog

摘要： 墨脱因其特殊的地理位置和巨大的海拔高差使得该地区拥有丰富的植物种类，其独特的自然地理和独特的气候条件为苔藓植物的分布孕育了多种多样的生境，形成了多样化的苔藓植物群落。为研究西藏墨脱苔藓植物多样性及其生活型组成特征，采用线路采集的方式对该地区苔藓植物进行调查和标本采集，物种鉴定和相关分析。结果表明：(1) 墨脱共有苔藓植物83科239属631种(含变种、亚种)，其中，角苔2科2属2种，苔类植物38科68属217种，藓类植物43科169属412种。该区苔藓植物有19个优势科，26个优势属和19个优势种。(2) 墨脱不同基质苔藓植物群落类型特征中，岩面薄土生群落共有苔藓植物327种，占该区苔藓植物总数的51.83%；石生群落共有苔藓植物216种，占该区苔藓植物总数的34.23%；土生群落共有苔藓植物173种，占该区苔藓植物总数的27.42%；树附生群落共有苔藓植物97种，占该区苔藓植物总数的15.37%，叶附生群落共有苔藓植物21种，占该区苔藓植物总数的3.32%。总体分析，墨脱良好的自然环境条件为丰富的苔藓植物生存提供了保障。

关键词: 苔藓植物, 物种多样性, 群落特征, 生活型, 墨脱