Judul: Potential Carbon Emissions Due to Harvesting The Mechanics in Natural Tropical Forest (Case Forest Consession PT. Salaki Summa Sejahtera, Island of Siberut, West Sumatra Province).
Abstrak: PT. Salaki Summa Sejahtera adalah perusahaan yang memiliki hak konsesi hutan di Pulau Siberut dengan luas 48.420 ha. Pengelolaan hutan dilakukan dengan sistem silvikultur Tebang Pilih Tanam Indonesia (TPTI). Pada areal kerja dilakukan kegiatan pemanenan dengan intensitas pemanenan yang berbeda-beda sesuai dengan potensi tegakan hutan. Intensitas pemanenan yang tinggi akan menimbulkan kerusakan tegakan tinggal dan keterbukaan areal yang besar. Areal kerja PT. Salaki Summa Sejahtera berada di kawasan Cagar Biosfer yang ditetapkan oleh UNESCO yang harus menekan kerusakan serendah mungkin. Pengelolan hutan yang terencana dengan baik dan penerapan Reduce Impact logging (RIL) merupakan cara yang baik untuk meminimalisasi kerusakan. Penelitian ini dilakukan dengan membuat 10 plot dalam petak tebang secara purposive sampling yang posisi plotnya diskontinyu. Kerapatan tegakan hutan rata-rata 118,6 pohon/ha dengan volume 248,03 m3/ha. Pada intensitas pemanenan 8,6 pohon/ha dengan volume tebangan 78,81 m3/ha menyebabkan kerusakan tegakan tinggal sebesar 31,4 pohon/ha (28,55%) yang dapat dikelompokan menjadi kerusakan berat 52,53%, sedang 33,09%, dan ringan 14,32%. Pohon yang paling banyak mengalami kerusakan berasal dari pohon berdiameter 20-29 cm yang mencapai 16,73%. Kondisi tegakan tinggal rata-rata setelah penebangan 78,60 pohon/ha dengan volume 132,53 m3/ha (53,43% dari stok sebelum penebangan). Keterbukaan areal yang terjadi akibat kegiatan penyaradan kayu sebesar 6,20%. Pemanenan kayu berpotensi melepas karbon ke udara yang berasal dari pohon yang diproduksi dan tegakan yang mengalami kerusakan berat rata-rata sebesar 46,74 ton C/ha atau 38,90% dari potensi stok karbon sebelum pemanenan kayu. Emisi karbon yang nyata terjadi di hutan adalah yang bersumber dari dekomposisi limbah sisa penebangan dan pohon-pohon rusak berat yang mungkin mengalami kematian rata-rata sebesar 16,86 ton C/ha.
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Judul: Kehilangan Cadangan Karbon pada Pemanenan Secara Mekanis (Studi Kasus Konsesi Hutan PT. Salaki Summa Sejahtera, Pulau Siberut Provinsi Sumatera Barat)
Abstrak: PT. Salaki Summa Sejahtera has 48.420 ha concession area on the island of Siberut. Management forest of silvicultural systems applied using Selective Cutting and Planting Indonesia (TPTI). Siberut island was set by UNESCO as a biosphere reserves in 1981 so that the impact of forest harvesting must be minimized to preserve the forest. Reduce Impact Logging is a technique that used to reduce impact of forest harvesting. This research aims to analyze an amount of forest openess and loss of carbon stocks and the relationship with harvesting volume . The research was conducted on RKT 2011 block of IUPHHK PT. Salaki Summa Sejahtera with an area of 962 ha. We conducted a 100% inventory of roads and log decks in RKT 2011 block. Forest stand density of ≥ 20 cm diameter average 76,11 trees/ha with an average volume 176,11 m3/ha. Carbon biomass of mature trees are 67,79 % total carbon biomass. Harvesting intensity of 5,80 trees/ha (47,89 m3/ha) is lower than annual allowable Cut (66,41 m3). Forest openness average of 6,45 % from main roads (0,64%), branch roads (2,12%), skid trails (3,24%), Landings (0,42%), and camp (0,03%). Forest openess is not correlated with harvesting volume (R2 = 0,38 %). Harvesting a tree needs 0,54 ha of roads and caused opened area 13,31 m2. Loss of carbon stocks are influenced by the amount of harvesting intensity (R2 = 0,98). Loss of carbon stocks that occured are 41,00 ton C/ha due to forest openness (5,05 ton C/ha), logging (30,62 ton C/ha), dan residual stand damage (5,33 ton C/ha). Crushed trees are categorized as a dead wood and reduced carbon stocks in a forest. Harvesting a tree caused loss of 0,86 ton C/ha carbon stocks
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Judul: Antibody Responses against Newcastle Disease and Evaluation of Infectious Bronchitis Maternal Derived Antibody on Vaccinated Layers.
Abstrak: Information of maternal derived antibody (MDA) and onset of immunity after vaccination is important to determine appropriate vaccination programme of chickens. The aim of this study was to evaluate duration of Infectious Bronchitis (IB) MDA and evaluate onset of immunity Newcastle Disease (ND) vaccination among layers. All layers were vaccinated using live ND and Infectious Bursal Disease (IBD) at one day old age, and received Avian Rhinotracheitis (AR) vaccine at 4 day old age. Serum samples were collected at various ages: 7, 10, 14, 20, 22, 24, 29 and 35 day old. The presence of ND antibodies was measured by the hemagglutination inhibition (HI) test, whilst the presence of IB antibodies was measured by enzyme-linked immunosorbent assay (ELISA). Our study showed that ND antibodies were at positive level until 24 day old age, and reached protective level ≥ 25 only at 7 day old age, whilst IB MDA were positive up to 17 day old age. This result indicating the needs of ND booster vaccination at least at 24 day old and IB vaccination at 17 day old age.
Keyword: antibody, Infectious Bronchitis, layers, Newcastle Disease, vaccination