Inventarisasi Anggrek Tanah di Cagar Alam Dolok Sibual-Buali Sumatera Utara

Abstract

HUMAYRA NASUTION. Inventory of Terrestrial Orchid in Dolok Sibual-buali Nature Reserve, North Sumatra. Under academic supervision of PINDI PATANA and YUNASFI. Dolok Sibual-buali Nature Reserve (CADS) is a conservation area in North Sumatra, covers ± 5.000 hectare area, altitude 1.200 – 1.700 m asl. Terrestrial orchid are orchids that grow in the ground in soil and the nutrition is obtained from the soil. Inventory of terrestrial orchid performed to study the diversity and altitudinal distribution of terrestrial orchid species in CADS. Study was performed in April - July 2013. Locations are determined by purposive sampling study with noticed the environmental factors, the vegetation observations used line plot transect which divided into 4 locations with different altitude intervals of every 100 m (1.200 m asl – 1.600 m asl), measuring plot 20 m x 100 m, divided to 5 subplots measuring 20 m x 20 m, so the plot number is 20. The result found 29 species of terrestrial orchids, divided of 17 genus with the individuals amount as much 816/0,8 hectare. Eria has the highest amount of species and individual that is 6 species and 156 individuals. Plocoglottis sp. 1 is the most widely distribution of species, found from interval I to III and also has the highest value of Importance Value Index is 85.84%. Location I has the highest value of Index of Diversity and Index of Equitability which are 2,75 and 0,47. Overall, similarity of terrestrial orchid species between sampling sites is low because the highest value of Index of Similarity was 57.14% and the lowest is 0%, none of which had ≥ 75% of similarity.