Font Size: 

This study aims to determine the diversity of fern vegetation in the Sangkulirang karst area - Mangkalihat Berau Regency and East Kutai Regency. The research was carried out for 2 months in 6 locations. Plotting method is done using purposive sampling method, with a plot size of 10 x 10 as many as 15 at each location. Diversity Index Value (H ') ferns in the Sangkulirang karst area - It was seen in all study locations ranging from 1.37 to 2.36 so that species diversity in all locations was not diverse. Dominance Index (C) in all research locations with a C value close to 0 so that it can be said at each location there is no dominating type. Evenness Index (e) at the location of Gunung Kapur Biatan Ulu Forest with an e value> 0.96 indicating the stability of the species at that location and at other research locations with a value of> 0.51. Similarity Index (ISs) in all study locations <50%, so that it can be seen that all types at each location are different.

Karst, Fern, Diversity Index, Sangkulirang-Mangkalihat