Keanekaragaman Tumbuhan Asing Invasif di Arboretum Fakultas Kehutanan Universitas Sumatera Utara

Abstract

Invasive alien plants are one or more plant species that are introduced into a different ecosystem and become dominant, disrupting the local ecosystem. In Indonesia, there are more than 300 types of invasive plants, which include a wide range from lower plants to trees. The aim of this study is to analyze species diversity, examine phylogenetic relationships, and analyze the distribution of invasive alien plants in the Arboretum of the Universitas Sumatera Utara. This research was designed using a quantitative approach. Data collection was conducted through vegetation analysis using the "systematic sampling with random start" technique, where the first plot was determined randomly and the subsequent plots were systematically placed based on predetermined intervals. The results of the study identified a total of 4,143 individual invasive alien plants belonging to 16 families and 29 species. The diversity index of invasive alien plants in the arboretum was calculated at 1.99, the evenness index was 0.5895, and the species richness index was 3.35. The highest importance value index at the shrub level was found in Clidemia hirta (Melastomaceae) with a value of 22.52%, while at the ground cover level it was Asystasia gangetica (Acanthaceae) with a value of 40.15%. Several species showed very close phylogenetic relationships, indicated by a similarity index of 1. These included Clidemia hirta with Melastoma malabathricum, Elephantopus scaber with Ageratum conyzoides, Eragrostis amabilis with Panicum maximum, Cyperus rotundus with Rhynchospora colorata, and Caladium bicolor with Alocasia macrorrhizos and Limnocharis flava. The distribution of invasive alien plants was found primarily on flat and gently sloping terrain, at distances ranging from 0 to 150 meters from the arboretum road, and from 0 to 375 meters from the river