Estimasi Populasi Orang Utan dan Model Perlindungannya di Kompleks Hutan Muara Lesan Berau, Kalimantan Timur

Orang utan (Pongo pygmaeus) adalah satwa langka yang dilindungi dengan penyebaran yang sangat terbatas di Sumatera dan Kalimantan. Dengan terbatasnya habitat dan populasi orang utan yang termasuk dalam kawasan konservasi, terjadinya degradasi hutan yang berdampak penting bagi habitat dan populasi, maka kawasan hutan di luar kawasan konservasi menjadi penting untuk pelestarian orang utan. Dalam hal ini hutan produksi telah diketahui sebagai ekosistem esensial untuk tujuan pelestarian. Populasi orang utan yang diteliti di kawasan Muara Lesan eks HPH PT Alas Helau seluas 12.228 ha dilakukan dengan metode penghitungan sarang. Penghitungan sarang dilakukan dalam jalur yang dibuat pada transek 500-1000 m. Dengan panjang total jalur 28 km, areal survei setara dengan 5,7% luas kawasan. Kerapatan populasi orang utan di Muara Lesan berkisar antara 1,92-7,13 individu/km² (rata-rata 3,69 individu) dengan jumlah total populasi 365-450 individu. Estimasi populasi dengan metode penghitungan sarang ini dipengaruhi oleh umur sarang yang mencapai 285 hari, potensi pohon pakan, perilaku pergerakan, termasuk migrasi serta kondisi habitat. Berdasarkan jumlah total populasi, orang utan di kawasan ini tergolong dalam populasi kritis. Perlindungan habitat dan populasi orang utan di kawasan HPH di Kalimantan, dalam pengelolaannya harus menetapkan wilayah konservasi yang cukup atau mengusulkan ekosistem esensial bagi habitat dan populasi orang utan di areal eks HPH yang tidak dikelola menjadi kawasan konservasi

Sebaran Dan Potensi Keruing (Dipterocarpus Spp.) Di Pulau Siberut, Sumatera Barat

Distribution and Potency of Keruing (Dipterocarpus spp.) on the Island of Siberut, West Sumatra. Nur. M. Heriyanto and M. Bismark. Distribution and potency of Dipterocarpus spp. (keruing) were studied in Siberut Biosphere Reserve area, covering Sot Boyak and Bekemen forest village, Siberut National Park, West Sumatra. Six research plots of 50 m x 50 m (0.25 ha) were laid down. The results showed that Dipterocarpus spp. density at the tree level were 31 trees/ha at Sot Boyak and 38 trees/ha at Bekemen forest village with important value index of 63.83% and 77.54% respectively. The strongest association of other trees to Dipterocarpus spp. were Hopea dryobalanoides Miq., Baccaurea bracteata Muell. Arg. and Endospermum diadenum Miq. as reflected respectively by 0.69, 0.67 and 0.56 of Ochiai index. Dipterocarpus spp. were commonly located on the slopes and ridges. The best grouping was on 50-59% Slopes. Slope relationship with the population distribution of Dipterocarpus spp. showed by the equation of Y = 5.83 ln (x) + 3.44 with R2 = 0.90. Regeneration of Dipterocarpus spp. in natural forest is highly dependent on the recruitment population. Saplings recruitment population was 556 individuals/ha, and seedling was 3,434 individual/ha

Status Populasi Dan Kondisi Habitat Surili {Presbytis Comatd) Di Cagar Alam Situ Patengan, Jawa Barat*[the Population Status and Habitat Condition of Grizzled Leaf Monkey, Presbytis Comata in Situ Patengan Nature Reserve, West Java]

Population and habitat survey was conducted in June-July 2000, at Situ Patengan Nature reserve, which aimed to record the current population data and habitat conditions. We recorded seven groups of grizzled leaf monkey/surili occurred at nature reserve, with number of 3 individual were vary between 4-8 individual each group and population density of 17/km . Sex ratio of individuals were 1:1.86, with percentage of age structures consisted of 17.95% adult male, 33.33% adult female, 25.64% juvenile, 20.51% offspring and 2.56% infant. Vegetation analysis recorded 56 species of plants found in the reserve. Some of the species were dominance, i.e. pasang (Quercus sp.), kihiur {Castanopsis javanica) and puspa {Schima walichii). Since population survey were conducted by Ruhiyat (1983) with population 2 3 density of 35 individuals/km and Adriana (1995) with population density of 3.5 individuals/km , the population density of the monkeys shown trend of decreasing. The reserve, located adjacent with some plantation areas and production forest area of Perum Perhutani, isolated the forest. This condition predicted as a potential threat to the habitat and population of the monkeys. The monkey's population will be a doomed population in the future

Ecological Impacts of Oil-Palm Plantation on Butterfly and Bird Species Diversity

The expansion of oil-palm plantations in Indonesia is often blamed as the driving causes of deforestation and impacts on environmental changes including the destructed biodiversity. Our understanding regarding environmental impacts on biodiversity is still limited. We address this issue by examining the diversity of butterfly and bird species under two type habitat conditions in Central Borneo. We calculated the butterfly and bird species number, richness, evenness, similarity, and composition inside the established oil-plantation area comprising four large-scale plantations and seven smallholding plantations, as habitat after plantation establishment.  In comparison, we did so similarly inside secondary forest and shrubs, as habitat before oil-palm plantation establishment.  Our results revealed that the habitat after plantation establishment exhibited a higher number of butterfly and bird species than the habitat beforehand.  However, the richness, evenness, and similarity indices for the species revealed variations, which were affected by dominant species in two habitats.  The establishment of oil-palm plantation brought about significant impacts on the composition of species and affected the species similarities between two habitats. The oil-palm plantation landscape and reserved forest vegetation were essential in supporting diversity and ecological role of species on habitat condition after oil-palm plantation establishment