幕阜山脉石松类和蕨类植物多样性及生物地理学特征

通过资料收集及野外调查, 得出幕阜山脉地区共有石松类和蕨类植物26科72属261种, 具有一定的东西过渡性, 为鳞毛蕨-铁角蕨植物区系, 最大属为鳞毛蕨属(Dryopteris) (29种)。其中, 庐山的物种丰富度较高(224种), 以铁角蕨属(Asplenium)为主; 幕阜山的物种密度较大(2.09种/km ²), 以卷柏属(Selaginella)为主; 九宫山以瓦韦属(Lepisorus)为主; 三者共通种有95种, 新特有现象较丰富。该区属种分化限制明显, 表现在单种科、属及寡种科、属占总科数的60%及总属数的80%。从区系成分看, 该区科、属以热带成分为主, 科和属的热带性成分与温带性成分比值(R/T值)分别为2.6和2.3。与同纬度带山地石松类和蕨类植物属的R/T值比较, 中亚热带与北亚热带交界带的蕨类植物属的R/T值在2.18-2.36之间; 种的R/T值为0.2, 为热带成分的5倍, 表现出明显的温带性质, 是罗霄山脉植物区系温带成分的重要组成部分。该区石松类和蕨类植物区系与华东、华南植物区系联系比较紧密, 表现出华东与华南两区系成分的交汇。

Diversity and biogeographical characteristics of lycophytes and ferns in Mufu Mountains,China

Field investigation and herbarium specimen information revealed that 261 species of lycophytes and ferns, belonging to 72 genera and 26 families were found in Mountain Mufu. It was characterized by Dryopteris-Asplenium flora with strong transiting distribution from east to west. The species richness was the highest (224 species) in Mount Lushan and the species density (2.09 species/km ²) was the highest in Mount Mufu. Besides Dryopteris included 29 species, Asplenium, Lepisorus and Selaginella were more abundant in Mount Lushan, Mount Jiugong and Mount Mufu, respectively. It shared only 95 common species among these three mountains, and the phenomena of neo-endemic genera and species was obvious. There were high restrictions on differentiation of genera and species in this area, which showed that monotypic family/genus and depauperate family/genus account for more than 60% of the total families and 80% of the total genera. The ratios of tropical elements to temperate elements (R/T) were 2.6 and 2.3 at the family and the generic level with tropical elements. Compared with the mountains in the same latitude zone, the R/T value at generic level in the junction zone of mid-subtropics and north subtropics was between 2.18-2.36. The R/T value was 0.2 at specific level with obvious temperate elements, which was an important component of the temperate flora of Luoxiao Mountains. The flora of lycophytes and ferns in this area was closely related to the flora of East and South China, showing the intersection of the two floristic components.