Analisis Vegetasi dan Identifikasi Tumbuhan Asing Invasif di Taman Wisata Alam (TWA) Sicike-Cike Sumatera Utara

Abstract

Invasive alien plants are plant species that native species and diversity of plants species. The aims of the study were to analyze sustainability of tree vegetation types, demographic analysis of Rhododendron malayanum in TWA Sicike-cike. Recommendations for the management of invasive alien plants on the border of TWA Sicike-cike were proposed. Purposive sampling method was used. Vegetation was observed using a nesting plot 20x20 m that placed 4 km along transect line observation of vegetation with a nesting plot system measuring 20x20m which is placed along the transect line as far as 4 km. Transect was divided into 27 lanes which are placed alternately from 100 to 200 m each lane consisted of 5-6 plots. So that the total plots within the area are 145, while the total plots on the border of TWA Sicike- cike are 120. The results showed Rhododendron malayanum has the highest Important Value Index at each level of tree vegetation, namely 46.29% (seedling), 26.41% (sapling), 55.53% (pole), and 28.99% (tree). Tree demographics in R. malayanum were dominated by trunk with diameters of 10-14 cm (78 individuals) and 20-24 cm (39 individuals), while trunk diameters of 15-19 cm (22 individuals) and 25-29 cm (23 individuals) have no difference. further, the greater the trunk diameter (>25 cm) the number of individuals was decreased (14-1 individuals). The presence of trees with a larger percentage tends to decrease drastically, this indicates that the TWA Sicike- cike still in normal forest condition. The highest of Important Value Index of understory vegetation was found is Impatiens platypetala (17.26%) found within the area and Argostemma peduculosum (31.24%) on the border of the TWA Sicike-cike. The index diversity of tree vegetation species was H'=3.26 (trees); H'=3,12 (pole); H'=3.00 (sapling); and H'=2.86 (seedling), understory vegetation in the area and boundaries was H'=3.48 and H'=3.00. The highest invasive plant risk value was found in Imperata cylindrica (235.8) followed by Ageratum conyzoides, Chromolaena odorata, Clidemia hirta and Melastoma malabathricum. In terms of management feasibility, the presence of I. cylindrica is recommended for direct eradication, while other IAS management is recommended in the form of monitoring, managing the site, managing invasive plant and protecting the site.