Analisis Vegetasi Kantong Semar (Nepenthes tobaica) dan Asosiasi di Desa Ria-Ria Kecamatan Pollung Kabupaten Humbang Hasundutan

Abstract

The Toba Pitcher Plant is one of the endemic plants that grows in Sumatra. The Toba Pitcher Plant, which grows natively in Sumatra, was first discovered by a Dutch botanist in the Batak area in South Tapanuli in 1856 (Clarke, 2018), often referred to as Tahul-tahul in the Batak language. This study aims to analyze the population structure of the Pitcher Plant in Ria-Ria Village, Pollung District, Humbang Hasundutan Regency, and to calculate the level of association of the Pitcher Plant with other plants in the habitat. The study was conducted from February to April 2022 using the nested plot method with different plot sizes for each growth stage (seedlings, saplings, poles, and trees). The data collected included the number of individuals per species and other vegetation parameters. Data analysis involved the calculation of the Importance Value Index (IVI), Shannon-Wiener Diversity Index, Richness Index, Evenness Index, Morisita Index, and Association Index using the Ochiai, Dice, and Jackard methods. The results showed that the Pitcher Plant population had a good structure with active regeneration characterized by a high number of seedlings and saplings. The diversity of vegetation types around the Pitcher Plant habitat was classified as moderate (H’ 1-3), with a moderate to high richness index. The distribution of Pinus individuals tended to form a clumped pattern (Id > 1). Association analysis revealed a significant relationship between Pitcher Plant and several other vegetation species, with the highest association index reaching a very high category (0.75– 1.00). These results provide an important picture of the ecological conditions and dynamics of the Pitcher Plant habitat in the forest area