ANALISIS VEGETASI HABITAT KEDIH (Presbytis thomasi) DI STASIUN PENELITIAN SORAYA KAWASAN EKOSISTEM LEUSER

Abstract

The natural habitat of the Kedih (Presbytis thomasi), an endemic primate of northern Sumatra, is increasingly threatened by illegal logging activities. This issue is also prevalent around the Leuser Ecosystem Area, one of the key habitats for Kedih. The Soraya Research Station, located within the Leuser Ecosystem, serves as an important habitat for this species. This study aims to determine the composition and structure of vegetation as a crucial component of the Kedih's habitat in the area. The research employed a field survey method using a line plot sampling technique. A total of 100 plots were established, with plot sizes of 2×2 m for seedlings, 5×5 m for saplings, 10×10 m for poles, and 20×20 m for trees. Materials used in this study included tally sheets and the vegetation present in the Kedih’s habitat (Presbytis thomasi), while the tools included: 1) nylon rope; 2) measuring tape; 3) compass; 4) smartphone with Avenza Maps installed; 5) measuring tape; 6) hagameter; 7) binoculars; 8) tally sheets and writing tools; 9) camera; 10) reference books. Recorded data included species count, stem diameter, crown-free height, and total height. Data analysis used the Shannon-Wiener Diversity Index and Importance Value Index (IVI). The results revealed 145 species from 45 families with a total of 1,914 individual plants. At the tree level, dominant species included Sloetia elongata and Shorea multiflora. The pole level was dominated by Sloetia elongata and Mallotus paniculatus, while the sapling level was dominated by Mallotus paniculatus and Glochidion glomerulatum. For seedlings, the dominant species were Mallotus paniculatus and Knema laurina. The vegetation diversity index ranged from moderate to high, indicating that the forest structure still supports the ecological function of the Kedih habitat. These findings highlight the importance of certain species such as those from the Moraceae and Euphorbiaceae families in maintaining forest ecosystem continuity for arboreal species like Kedih. Therefore, vegetation conservation in this area is crucial to ensuring the sustainability of Kedih populations in their natural habitat.