ABSTRAK
Telah dilakukan penelitian tentang komposisi dan struktur hutan pamah serta regenerasi pohon di zona inti bagian barat Taman Nasional Bukit Duabelas, Jambi pada bulan Oktober-November 2012. Plot seluas satu hektare diletakkan di tanah datar di punggung bukit. Plot dibagi menjadi 100 petak yang masing-masing berukuran 10x10 m untuk pencacahan pohon. Petak 5x5 m dan 1x1 m disarangkan dalam plot tersebut untuk pencacahan belta dan semai. Hasil penelitian menunjukkan bahwa pohon dengan diameter setinggi dada (DSD) ≥ 10 cm tercatat sebanyak 463 individu, mewakili 91 spesies dan 36 famili, dengan total area dasar (AD) 27,21 m2 dan indeks keanekaragaman shannon-wiener (H’) 4,04. Spesies dominan berdasarkan nilai kepentingan (NK) adalah Archidendron bubalinum dengan NK tertinggi sebesar 13,93%, diikuti Dacryodes sp. 12,32% dan Antidesma neurocarpum sebesar 12,17%. Archidendron bubalinum adalah spesies dengan kerapatan tertinggi (29 pohon/ha) dan frekuensi tertinggi (22). Koompassia malacensis dari famili Caesalpiniaceae memiliki AD tertinggi 2,23 m2 atau 8,18% dari total AD dalam plot. Burseraceae (32,73%) dan Dipterocarpaceae (25,78%) merupakan famili dengan NK tertinggi, sedangkan famili dengan spesies terbanyak tercatat pada famili Euphorbiaceae (7 spesies). Sebanyak 12 spesies (71 individu) masuk dalam kategori redlist IUCN, 2 di antaranya masuk dalam kategori Critically Endangered (Prashorea lucida dan Shorea acuminata), Endangered (Shorea leprosula), Lower Risk (8 spesies), dan vulnerable (1 spesies). Tercatat sebanyak 511 individu pada tingkat semai, yang diwakili oleh 57 spesies dan 32 famili. Pada tingkat belta tercatat 570 individu yang diwakili oleh 87 spesies dan 36 famili. Di antara 10 spesies pohon yang memiliki kerapatan tertinggi, terdapat 6 spesies (Archidendron bubalinum, Dacryodes sp., Antidesma neurocarpum, Ochanostachys sp., Knema laurina, dan Hydnocarpus sp.) memiliki sebaran lengkap. Empat spesies hanya memiliki sebaran anakan di tingkat belta (Koompassia malacensis, Parashorea lucida, Leptonychia caudata, dan Dacryodes rostrata). Sebanyak 65 spesies atau 71,43% dari semua spesies pohon beregenerasi dalam petak penelitian.

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ABSTRACT
Study on the composition, structure, and regeneration of the lowland forest in the western part of the core zone of the Bukit Duabelas National Park, Jambi, was conducted in October-November 2012. A one-hectare plot was established on a flatland, over a ridge. It was divided into 100 quadrats of 10 x 10 m each for the enumeration of trees. Subplots of 5x5 m and 1x1 m were nested within the 10x10 m quadrats for enumeration of saplings and seedlings. The results showed that as many as 463 trees with a diameter at breast height (DBH) ≥ 10 cm were recorded, representing 91 species and 36 families, with a total basal area (BA) of 27.21 m2 and the Shannon-Wiener diversity index (H ') of 4.04. The prevalent species in the plot was Archidendron bubalinum with highest importance value (IV) of 13.93%, followed by Dacryodes sp. with IV of 12.32% and Antidesma neurocarpum with IV of 12.17%. Archidendron bubalinum was the species with the highest density (29 trees/ha) and highest frequency (22). Koompassia malacensis from Caesalpiniaceae was a species having the highest BA 2.23 m2 or 8.18% of the total BA in the plot. Burseraceae (32.73%) and Dipterocarpaceae (25.78%) were a families with the highest IV, while the families with the highest number of species recorded was Euphorbiaceae (7 species). A total of 12 species (71 individuals) occurring in the plot were listed in the IUCN redlist category, 2 of which were in the category of Critically Endangered (Prashorea lucida and Shorea acuminata), Endangered (Shorea leprosula), Lower Risk (8 species), and vulnerable (1 species). We recorded 511 individuals of tree seedling, representing 57 species and 32 families. At the sapling stage 570 individuals were recorded representing 87 species and 36 families. Out of 10 species of tree with the highest density, 6 species (Archidendron bubalinum, Antidesma neurocarpum, Dacryodes sp., Hydnocarpus sp., Knema laurina, and Ochanostachys sp.) had a good number of saplings and seedlings. Only four species had individuals at sapling stage (Koompassia malacensis, Parashorea lucida, Leptonychia caudata, and Dacryodes rostrata). A total of 65 species or 71.43% of all tree species were regenerating in plot.