Structure, composition and diversity of tree species in Martelu Purba Nature Reserve, North Sumatra, Indonesia

Abstract. Rangkuti AB, Hartini KS, Susilowati A, Rambey R, Harahap MM, Arinah H, Irmayanti L, Pamoengkas P, Indriani F, Peniwidiyanti, Ruhidi A. 2023. Structure, composition and diversity of tree species in Martelu Purba Nature Reserve, North Sumatra, Indonesia. Biodiversitas 24: 78-85. Reserve is one the conservation areas Sumatra that functions to protect biodiversity. However, there limited information related vegetation community contained nature reserve. This study aimed assess diversity, structure as well reveal status The research used line transect method with a total 112 observation plots representing various environmental conditions. results showed were 39 belonging 25 families, 31, 25, 24, 26 at tree, pole, sapling, seedling stages, respectively. Shorea platyclados Syzygium cerasiforme highest Important Value Index (IVI) pole stages 173.04% 31.01%, respectively, while Gamblea malayana was most important sapling IVI 66.43%, 30.00%, Shannon-Wiener index (H') categorized low (1.58), Margalef richness (DMg) high all growth Evenness (E) high, indicating evenly distributed across plots. distribution diameter classes ranged from 20 - 40 cm for trees smallest 81-110 largest diameter. Based on their status, two concerns, namely Coffea arabica (Endangered) Lithocarpus maingayi (Vulnerable). application good silvicultural methods needs be carried out context efforts. One example through vegetative propagation long flowering periods.