Rare Pteridophytes are disproportionately frequent in the tropical forest of Xishuangbanna, Yunnan, China

摘要

The richness and cover of tropical fern life-forms - terrestrial and epiphytic - vary due to their ecology and evolutionary history. It is important to understand the responses of both terrestrial and epiphytic species in relation to topography, as elevation and other aspects, to better predict their distribution. This study has investigated the richness and cover of terrestrial and epiphytic fern species in the landscape of Xishuangbanna, Yunnan, China. The ferns were classified as either rare or common based on their occurrence and the cover values from 75 transects. A General Linear Model was created to understand the impact of the elevation and topographic aspects on the rare and common fern species. A total of 130 ferns species were found. Out of the total richness, 74% of species were considered rare and assessed as having either a narrow or a wide distribution but low frequency. The rarity increased up to 90% for the epiphytic species.