Keanekaragaman Jenis Tumbuhan Pada Plot Monitoring Permanen Lagan Bras (Dipterocarpus cinereus) Di Pulau Mursala

Abstract

Mursala Island has a lot of potential for abundant natural resources, biodiversity, and historical and cultural heritage. Lagan bras (Dipterocarpus cinereus) is one of the dominant tree species in the Dipterocarpaceae family. Dipterocarpus species are well known and much sought after because their wood can be used as raw material for boatbuilding and construction. Dipterocarpus cinereus has been categorized as Extinct on the IUCN Red List since 1998. Dipterocarpus cinereus is declared endemic only in Mursala, on a small island in Central Tapanuli, North Sumatra. It was initially collected in 1916 and declared as Dipterocarpus cinereus in 1928 by Peter Ashton. The aim of this study was to establish a permanent monitoring plot of Lagan Bras (Dipterocarpus cinereus) and analyze preliminary data on the population structure of Lagan Bras and the composition of the plant community contained within the plot. The plot size was 0.25 hectares, 316 individual trees consisting of 45 species and 28 families were obtained. In this permanent plot there are 11 individuals of the target tree, Lagan Bras with the largest diameter of 60 cm. This data collection uses the Purposive Sampling method, which searches for the target tree Lagan Bras and all trees by recording all invididuals in the plot starting from 5 cm for the trunk diameter (DBH). The diversity index was high with a value of 3.21. The evenness index in the plot was 0.8. The stand structure resembles an inverted letter “J”. This research location is included in a mature forest that is not disturbed by the ecosystem. The total biomass of all tree species is 407.33 tons/ha which is classified as low.