POPULASI DAN HABITAT OWA (Hylobates albibarbis Lyon, 1911) DI RAWA GAMBUT TAMAN NASIONAL SEBANGAU DAN PERBUKITAN BELANTIKAN KALIMANTAN TENGAH
AISYAH HADI RAMADANI, Dr. Tjut Sugandawaty Djohan, M.Sc.
2014 | Tesis | S2 BiologiStatus populasi owa (Hylobates albibarbis) terkini menjadi pertanyaan karena kerusakan hutan gambut yang terus berlangsung dan semakin luas. Densitas owa dan profil habitat dipelajari dalam lanskap hutan rawa gambut TN Sebangau dan hutan perbukitan Belantikan. Lokasi kajian hutan rawa gambut dari tepi sungai ke daratan dipilah menjadi riparian rawa, mixed forest, dan inland forest. Lokasi hutan perbukitan dipilah riparian dan mixed forest. Pada tiap lokasi, densitas owa dihitung dengan metode belt transect 2 km x 100 m dengan ulangan 2 kali. Data owa yang diukur adalah cacah kelompok dan individu, serta posisi owa. Vegetasi penyusun habitat dipelajari dengan metode kuadrat plot 20 m x 20 m pada setiap belt transek dengan ulangan 2 kali. Profil hutan digambar dengan metode Oldeman. Data yang diukur meliputi growthform, cacah spesies, cacah individu, tinggi total, tinggi cabang pertama, dan luas kanopi. Hasil mengungkapkan bahwa habitat owa di riparian Sebangau dalam kondisi rusak yang disusun oleh 1 strata didominasi pandan. Sebaliknya, riparian rawa di Punggualas disusun oleh strata yang lengkap, yaitu 4 strata. Hutan mixed forest rawa gambut baik di Sebangau maupun di Punggualas dan perbukitan Belantikan disusun oleh 4 strata dan owa menyukai habitat ini. Cacah spesies pohon pakan di hutan rawa gambut dan perbukitan berturut-turut terdiri dari 43 spesies yang merupakan 29% cacah spesies yang hadir dan 38 spesies dari 28% spesies yang hadir. Spesies pohon pakan yang mendominasi hutan rawa gambut dan perbukitan yaitu Campnosperma coriaceum, Diospyros bantamensis, Dyera lowii, Myristica elliptica Ochanostachys amentosa, dan Eugenia sp. Cacah individu pohon pakan di hutan rawa gambut dan perbukitan berturut-turut 293 individu per ha atau 42% pohon yang hadir dan 217 individu per ha atau 63% pohon yang hadir. Kondisi mixed dan inland forest rawa gambut membaik, kecuali riparian Sebangau. Kolonisasi pandan mengancam pemulihan habitat riparian rawa tersebut. Owa ditemukan pada semua lokasi kajian baik di Sebangau dan Belantikan kecuali di riparian rawa gambut rusak. Kehadiran owa di Sebangau dan Belantikan terdiri dari 5 – 10 kelompok per km 2 dengan 7,5 – 25 individu per km 2 yang dominan di riparian Belantikan alami. Hutan riparian terrestrial Belantikan bukanlah habitat owa. Adanya populasi owa tersebut karena kerusakan hutan rawa gambut sejuta hektar tahun 1995-1998. Akan tetapi populasi owa tersebut saat ini terancam oleh aktivitas logging. Densitas owa di hutan rawa gambut Sebangau cenderung naik. Kenaikan populasi mengindikasikan pemulihan habitat di mixed forest rawa tersebut. Sebaliknya hutan rusak rawa riparian dalam skala besar, yang seharusnya menjadi habitat owa, pemulihan hutannya harus ada usaha rehabilitasi.
Status of owa, Hylobates albibarbis, at present is questioned due to the big disturbance of peat swamp forest. We studied the owa densities at Sebangau and Punggu Alas peat swamp and Belantikan forests hill at landscape from riverine, mixed, to inland forests. At each location, the number of individual and group were measured using belt transect of 2 km x 100 m with two replicates. The position of owa at forest profile was noted. The parameters of vegetation, growth form, number of species, density, DBH, plant height, canopy coverage were measured using quadrate plot of 20 m x 20 with two replicates at each belt transect. We performed the forest profiles using Oldeman method. The result revealed that the riverine peat swamp forest at Sebangau was disturbed, and only had one layer of forest floor vegetation which dominated by Pandanus sp. In contrast, all the forest at landscape both r iverine, mixed, and inland forests were in good conditions and had four layers of forest profile, composed of tree, sapling, and floor vegetation. Owa preferred very much the riverine-peat swamps. The number of food trees at both swamp and hill forests cons ist of 43 and 38 species inconsecutively with 29% and 28% of the number species present. At the peat swamp and hill forest, the dominant food trees were Campnosperma coriaceum, Diospyros bantamensis, Dyera lowii, Myristica elliptica Ochanostachys amentosa, dan Eugenia sp. The total number of food tree species at the swamp consist of 293 individual tree per ha and 42% of present trees, and the hill forest were 217 individual per ha with 63% of the tree present. The mixed and inland forest of peat swamp forests recovered since the National Park established , except at the riverine of Sebangau. The colonization of Pandanus threatened recovery of the forest. We found the owas at all the study sites, except at the riverine of Sebangau peat-swamp. We found owa at Sebangau and Belantikan between 5-10 grup per km 2 and consisted of 8 -25 individual per km 2 . Belantikan riverine forest were not owa habitat. The presence of owa in hill forest due to peat swamp disturbance as one million mega rice project at 1995-1998. However the owa population at the Belantikan hill forest were threatened due to logging activities. The owa population at swamp forest increased reflected the mixed and inland Sebangau forest swamp recover. Its mean that national park status of Sebangau and Punggualas protected the owa population. In contrast, the disturbed current at riverine forest at Sebangau can not recover without human rehabilitation efforts due to r and k strategies of Pandanus sp. Those represent that riverine peat swamp forest become important for the survival of future owa habitat.
Kata Kunci : endangered, status populasi, strata kanopi, riparian
