Komposisi Vegetasi dan Asosiasi Pinus (Pinus merkusii) di Hutan Lindung Desa Parsingguran Kecamatan Pollung Kabupaten Humbang Hasundutan

Abstract

Pinus is one of the endemic plants that grow in Sumatra. The first Pinus species native to Sumatra was discovered by a German botanist in the Sipirok area of South Tapanuli in 1841, and is commonly referred to as the 'tusam' tree in Indonesian. This study aims to analyze the population structure of Pinus merkusii in the Parsingguran Village Protected Forest, Pollung District, Humbang Hasundutan Regency, and to assess the association level of Pinus merkusii with other plant species in its habitat. The research was conducted from February to April 2022 using a plot-line 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 calculating the Importance Value Index (IVI), Shannon-Wiener Diversity Index, Richness Index, Evenness Index, Morisita Index, and Association Index using Ochiai, Dice, and Jackard methods. The results showed that the Pinus merkusii population has a well-structured and actively regenerating population, as indicated by the high number of seedlings and saplings. The vegetation diversity in the Pinus habitat was classified as moderate (H' 1–3), with moderate to high richness index. The distribution pattern of Pinus individuals tended to form clumps (Id > 1). Association analysis revealed significant relationships between Pinus merkusii and several other vegetation species, with the highest association index falling into the very high category (0.75–1.00). These findings provide essential insights into the ecological conditions and habitat dynamics of Pinus merkusii in the protected forest area.