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The conservation of the endemic tree species Dipterocarpus littoralis (Bl.) Kurz. is hampered by the paucity ofinformation on its population biology and ecology. Consequently, a targeted survey was carried out in the WestNusakambangan Nature Reserve to assess its population size and structure as well as habitat preferences. In total, 676individuals of D. littoralis were located at 52 locations, with an extent of occurrence of 3.66 km2 and an area ofoccupancy of 1.71 km2. The population had an inverse-J-shaped distribution of diameter at breast height (DBH), with63% of individuals in the 0-5 cm class and another 21% in the 5-10 cm class; only 11 (1.6%) mature individuals(DBH≥30) were found. D. littoralis was associated with steep, low, southwest-facing sites and sites that had high littercover and thickness. Illegal logging and fuel-wood chopping were the main threats to D. littoralis and its habitat. Inaddition, an invasive shrub, Langkap (Arenga obtusifolia, Arecaceae), was a potential competitor with the seedlingsthroughout the reserve. In view of its endemism, narrow range and localized distribution, small population,environmental preferences, and the severe threats from anthropogenic activities and invasive species, D. littoralisappears to more than justify its conservation status of Critically Endangered.Status Populasi dan Preferensi Habitat Jenis Kritis Dipterocarpus Littoralis di Nusakambangan Barat,Indonesia. Usaha konservasi jenis endemik Dipterocarpus littoralis (Bl.) Kurz. terhambat karena kurangnya informasimengenai biologi dan ekologi populasi tumbuhan ini. Oleh karena itu pada penelitian ini dilakukan survey terarah diCagar Alam Nusakambangan Barat untuk mengetahui struktur dan ukuran populasi serta preferensi habitat dari D.littoralis. Total sebanyak 676 individu D. littoralis di temukan di 52 lokasi dengan tingkat keberadaan (extent ofoccurrence) 3,66 km2 dan luas area yang ditempati (area of occupancy) 1,71 km2. Populasi D. littoralis memilikisebaran diameter batang setinggi dada (DBH) berbentuk huruf J terbalik dengan persentase individu dalam kelas DBH0-5 cm sebesar 63%, kelas 5-10 cm sebesar 21% dan individu dewasa (DBH ≥30) hanya sebesar 1,6%. Keberadaan D.littoralis berasosiasi dengan lokasi yang terjal, rendah, menghadap ke tenggara dan memiliki tutupan serta ketebalanserasah yang tinggi. Penebangan dan pengambilan kayu bakar secara liar merupakan ancaman utama terhadapkeberadaan D. littoralis dan habitatnya. Selain itu, tumbuhan invasif Langkap (Arenga obtusifolia, Arecaceae) yangtersebar di seluruh cagar alam merupakan saingan utama anakan D. littoralis. Karena bersifat endemik, area sebaranyang sempit dan terlokalisasi, ukuran populasi yang kecil, preferensi terhadap habitat tertentu, dan ancaman yang seriusdari aktifitas manusia dan jenis invasif, maka D. littoralis memiliki dasar yang kuat untuk tetap dalam status konservasiKritis (Critically Endangered). |
