POPULATION STRUCTURE, REGENERATION STATUS AND CONSERVATION MEASURES OF THREATENED CYATHEA SPP.

The present study assessed the population structure, regeneration status and conservation of threatened tree ferns Cyathea, namely, C. brunoniana, C. gigantea and C. henryi in Seijosha forest, Arunachal Pradesh, north-east, India. Individuals of C. henryi had a maximum density of 45 individuals ha(-1) while C. brunoniana and C. gigantea had a maximum of 35 individuals ha(-1). The population structure showed four general class distribution patterns (i.e. reverse J-shape, Bell shape, irregular shape, and J-shape). Only C. brunoniana and C. henryi showed reverse J-shaped pattern at two sites, which indicated a stable population. The regeneration status for C. gigantea was poor at most of the sites. There were fewer individuals of young, immature and adult plants of Cyathea, and some species showed poor or no regeneration at certain sites. The conservation status of young/immature/adult individuals was occasional and infrequent. The study revealed many factors threatening Cyathea and suggested some corrective measures which can be helpful for its conservation.