中国山顶苔藓矮曲林的分布及其特征

Distribution and characteristics of the mossy dwarf forests in China

利用实地调查和相关文献资料,确定山顶苔藓矮曲林在我国的分布情况,统计分析其植物组成成分和区系地理成分,并计算群落的相似性.结果表明:山顶苔藓矮曲林在我国南方大部分省区呈"岛屿"状分布,最北限位于河南伏牛山;其分布地点随着我国三级阶梯的地形变化及各山体具体海拔高度不同而不同;该类群落种类组成较为贫乏,共计蕨类植物16种,种子植物251种;其区系特点是深受热带亚热带区系的影响,又具有温带区系的性质;山顶苔藓矮曲林群落东西部差异较大,东部地区群落相似性较高;群落丰富度总体呈现出西高东低、南高北低的趋势.鉴于该类群落生境的独特性和分布的特殊性,一方面其生态系统比较脆弱,应加强保护;另一方面应开展广泛、详细的调查,对其进行系统、深入的研究.

Based on plots investigation and literatures of the mossy dwarf forests, this study tried to determine their distribution in China, analyzed the species composition and floristic geo-graphic elements of this kind of forests, and calculated the similarity among communities. The results showed that these communities scattered in a large areas of southern provinces as ＂islands＂ in China, with the northern boundary located in the Funiu Mountain in Henan Province. The distribution sites appeared to vary with three-step topography in China and altitude in every specific mountain. The floristic composition which included 16 species of Pteridophytes and 251 species of Spermatophytes was not complicated. The floriatic areal-type elements were af- fected by tropical and subtropical flora, and also influenced by temperate. From east to west, sig- nificant differences was found to exist in mossy dwarf forest communities： in the east the similarity was higher while the richness was lower in the eastern and northern part. In view of the unique habitats and particular distribution of these communities, more attention should be paid to the protection of this type of ecosystem and further studies are needed.