岩下自然保护区蕨类植物区系特征

依据植物的现代地理分布,岩下自然保护区蕨类植物种的分布可以划归11个分布区类型和7个亚型,其中东亚成分和热带亚洲成分构成了该区区系的主体。区系分析表明,该地区蕨类植物处于东亚植物区系中,但热带亚洲成分对该区也有一定影响,表现为亚热带向温带过渡的特点。其区系地理成分复杂,从属来看,以热带、亚热带分布的属占优势,有33个,占总属数的78.6%,说明有较高的热带亲缘。从种来看,以东亚地理成分占优势（42种）,加上中国特有成分（5种）占总种数的42.3%。表明岩下蕨类植物区系属东亚区系。

The Characteristics of Pteridophyte Flora in Mt.Yanxia Nature Reserve

Based on modern geographical distribution of plants,the pteridophyte species in Mt.Yanxia Nature Reserve can be divided into 11 area types and 7 subtypes.Temperate East Asia distribution and Tropical Asia distribution are the main elements of the area-type in this area.The analysis indicate that pteridophyte of this area belong to East Asia pteridophyte,however,Tropical Asia distribution also have certain effect on this area and show the feature of subtropical transition to temperate area-type.Floristic and geographic elements are complicated.At genus level,tropical-subtropical distribution types are dominant,with 33 genera accounting for 78.6% of the total genera,this indicates that pteridophyte flora at genus level is related to tropical and subtropical nature.At species level,East Asia elements(42 species) take the largest proportion,including endemic Chinese elements(5 species),accounting for 42.3% of the total species.Those indicate that Mt.Yanxia pteridophyte flora belongs to East Asia flora.