Judul: Perubahan Massa Karbon Akibat Pemanenan Kayu di Perusahaan Pemanfaatan Kayu Pulau Siberut
Abstrak: One of the primary role of a forest is, not only as the supplier of carbon, but also as the natural absorbent for Carbon Dioxide (CO2), and as well as the source for greenhouse gas if not managed properly. The purpose of this research is to analyze the magnitude of change in carbon mass, resulted from logging activities. This carbon mass was obtained from lab test, conducted on tree stems, branches, twigs, leaves and barks. Based on t-student test the result for the average level of contained carbon were 53.86% on stems, 51.98% on branches, 31.58% on twigs, 27.91% on leaves, and 32.01% on barks. Forest harvesting with an average stands density of 71.5 trees/ha and with a harvesting intensity of 8.8 trees/ha caused a stand damaged of 16.17 trees/ha. The amount of carbon mass has decreased for about 43.26% because of the harvesting activities, which initially had the amount of 141.89 ton/ha, now has become 80.00 ton/ha after harvesting.
Keyword: forest harvesting, carbon mass, greenhouse gas

Judul: Limbah Pemananen Kayu dan Massa Karbon Tersimpan pada Limbah Pemanenan Kayu di Perusahaan Pemanfaatan Kayu Kalimantan Timur
Abstrak: In order to achieve the sustainable forest management certification, a forest company PT Ratah Timber needs to identify the residue generated from logging, the exploitation factor, and the measurement of carbon mass stored on the logging residue. The measurement of logging residue were conducted on felling areas, landing site, and log yard. The logging residue was defined on stumps, main stems, upper stems, and branches with the minimum diameter of 5 cm. The mass of the carbon were obtained from laboratory analysis. The result showed that the logging residue on the felling area had the average number of 46.73 m³/ha (98.19%), 0.86 m³/ha (1.81%) at landing site, and 0 m³/ha (0%) at log yard, while the logging residue based on parts of the tree were 9.21 m³/ha stumps, 21.96 m³/ha main stems, 11.32 m³/ha upper stems, and 6.06 m³/ha branches. The exploitation factors in this research were calculated by taking into account the number of logging residue percentage, and using the felling index, skidding index, and hauling index approach, the result of the calculation showed that the exploitation factor were at the level of 0.69. These mass of carbon were stored inside the logging residue from the logging, with the approximate number of 33.49 ton C/10 ha.
Keyword: sustainable forest management, carbon mass, logging residue, exploitation factor

Judul: Pengujian Virus Newcastle Disease Gen VII Isolat Lapang Sebagai Virus Standar Pada Uji Tantang Vaksin
Abstrak: This study was conducted to determine the standard of Newcastle disease virus Gene VII field isolate as a virus challenge to vaccine test. A virus suspension that has previously been tested by HA test then titrated with EID50 using 30 Specific Pathogen Free (SPF) of 10 day old chicken embryonated eggs. In addition, chicken lethal dose50 (CLD50) test were used to determine the virus titer that could cause 50% death of the chicken population. The CLD50 test was used 25 day-old-chickens (DOC) divided into 5 groups. The virus was diluted from 10-1 to 10-8. The 104 to 10-8 dilution of NDV was infected to every group of chicken via eyedrop and intranasal with 0.1 ml/chicken dosage. Haemagglutination test showed that the allantoic fluid were contain high titers of NDV is 512 HAU. The infective NDV that had been titrated by EID50 test showed the virus titers is 109 EID50/0.1 ml or 1010 EID50/ml and the virus titers of CLD50 test e.i 106.48 CLD50/0.1 ml or 107.48 CLD50/ml. These results can be concluded that the NDV Gene VII field isolates were most appropriate to be used as a standard virus to vaccine test
Keyword: Newcastle Disease Virus Gene VII, HA tes, EID50 test, CLD50 test