Keanekaragaman Potensi Regenerasi Vegetasi pada Hutan Rawa Gambut: Studi Kasus di Kawasan Hutan Dengan Tujuan Khusus (KHDTK) Tumbang Nusa, Kalimantan Tengah - Dony Rachmanadi; Eny Faridah; Peter J Van Der Meer (Fakultas Kehutanan Universitas Gadjah Mada, 2017)
Degradasi ekosistem hutan termasuk hutan rawa gambut umumnya diwakili oleh degradasi tutupan vegetasi. Degradasi hutan cenderung mengikuti gradien jarak dari tepi hutan menuju ke dalam hutan. Tujuan dari penelitian adalah untuk mengetahui keanekaragaman dan dominasi potensi regenerasi alami di hutan rawa gambut di Kalimantan Tengah. Anakan alam, guguran buah, dan biji yang tersimpan di lapisan tanah sebagai indikator potensi regenerasi alami diukur dari serangkaian plot terletak mengikuti gradien jarak. Hasil penelitian menunjukkan perbedaan potensi regenerasi alami mengikuti gradien jarak secara signifikan. Keragaman potensi regenerasi alami cenderung menurun mengikuti gradien gangguan, di mana yang terendah ditemukan di tepi hutan. Anakan alam di tepi didominasi oleh Combretocarpus rotundatus (Miq.) Danser sementara Litsea oppositifolia L.S. Gibbs mendominasi di bagian dalam. Guguran buah didominasi oleh Combretocarpus rotundatus di semua gradien jarak pada musim kemarau, sementara itu Palaquium sp. mendominasi gradien dalam hutan dan Combretocarpus rotundatus mendominasi gradien tepi hutan selama musim pancaroba. Hal ini menunjukkan bahwa musim memberi efek signifikan pada jumlah biji, jumlah spesies, dan keanekaragaman guguran buah, dan ketiga indikator potensi regenerasi ternyata lebih tinggi selama musim pancaroba. Biji di lapisan tanah didominasi oleh Tristaniopsis obovata (Benn.) Peter G. Wilson & J.T. Waterh di gradien dalam hutan dan Diospyros sp. di gradien tepi. Namun, biji di lapisan tanah di gradien tepi ini merupakan jenis yang menyusun pada gradien dalam hutan (50% indeks kesamaan). Hal ini menunjukkan bahwa penyebaran benih dari hutan sebagai sumber inokulum masih bisa mencapai tepi dan juga menunjukkan bagaimana kehadiran vegetasi di gradien tepi sebelum terjadi gangguan.Kata kunci: anakan alam; biji di lapisan tanah; gradien jarak; guguran buah; hutan rawa gambut Potential Diversity of Natural Regeneration in Peat Swamp Forest: A Case Study at Forest for Specific Purpose (KHDTK) Tumbang Nusa, Central KalimantanAbstractDegradation of forest ecosystem including peat swamp forest is generally represented by the degradation of its vegetation cover. Forest degradation tends to follow edge-to-interior distance gradient. This study aimed to determine the diversity and dominance of natural regeneration potential in peat swamp forest at Central Kalimantan. Seedling bank, seed rain, and seed soil bank as the indicators of natural regeneration potential were measured from series of plots located following the distance gradient. The results showed that the difference in natural regeneration potentials followed the distance gradient significantly. The diversity of natural regeneration potential tends to decrease following disturbance gradient, where the lowest was found near the edge. Seedling bank at the edge was dominated by Combretocarpus rotundatus (Miq.) Danser while Litsea oppositifolia L.S. Gibbs dominated at the interior. The seed rain was dominated by Combretocarpus rotundatus at all sites during dry season while during intermediate season, Palaquium sp. dominated the interior and Combretocarpus rotundatus near the edge. It was showed that climatic season gave significant effects on seed number, species number, and diversity of seed rain in which all the three regeneration indications were higher during intermediate season. The seed soil bank was dominated by Tristaniopsis obovata (Benn.) Peter G. Wilson & J.T. Waterh near to the interior and by Diospyros sp. at the edge. However, seed soil banks at the edge zone were dominated by species composing the interior forest (50% similarity index). This shows that the seed dispersal from forest as inoculum source can still reach the edge and also indicates existing vegetation at the edge prior to disturbance.