Judul: Dinamika Karbon Tanah Akibat Konversi Lahan dan Hubungannya dengan Penambahan Gas Rumah Kaca di Atmosfer (Studi Kasus : Pulau Sumatera)
Abstrak: Soil is the largest carbon storage in terrestrial ecosystems, thus soil plays an important role in the global carbon cycle. The increasing of human needs in terms of economic, social, and institutional are the factors affecting land use change in order to meet the necessities of life. Changes of vegetation / land cover / land use causes changes in biomass and biomass carbon stock. This conditions affecting amount and distribution of plant’s scrabs and tissue underneath which are the main source of soil organic material, thus will affect the soil organic carbon stock. Overall, if the organic soil material changing, the organic carbon will change as well. Changes in land cover can increase carbon loss through several mechanisms, namely: 1) destroy soil aggregates that protect the soil organic materials from decomposition, 2) stimulate microbial’s activity by improving soil aeration, 3) mixing the fresh organic material into soil which the conditions are more favourable for decomposition rather than in the soil surface. In addition, cultivate land more easily eroded, resulting in the loss of carbon. Moreover, land use can cause soil more easily being eroded. This research is aimed to estimate soil carbon emissions due to land use changes that occurred since 2003 to 2006 on mineral soil and peat soil on first soil layer in Sumatra island using the method of soil carbon emissions estimation created by the IPCC in 2006. The amount of emissions that occur due to land use change in mineral soil is 38.435.198 acres, which its emissions is 83.025 tons/year of C or equal to 304.704 ton/year of CO2. While the changes that occur in peatlands in Sumatra to contribute as much 41.236.091 tons/year of C or equal to 151.336.454 tons/year of CO2 for 6.643.778 acres of land area change.
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Judul: Emisi Karbon Dioksida Dari Tanaman Kelapa Sawit Pada Lahan Gambut Di Sumatra
Abstrak: Peatlands are formed by decomposed plants residues, with vegetation that are submerged. The process of peat formation occurs when the rate of deposition exceeds the rate of loss of organic materials. Peatlands in the world only 3% of the entire land, but store 30% of the world terrestrial carbon. Indonesia is estimated to have the largest amount of carbon in tropical peat of 57,4 Gt. Over the past 20 years, peatlands have been converted for agriculture. Oil palm plantations in Indonesia are mostly developed on peat soil. In 1990, the area of oil palm on peat land in Sumatra was 17.985 hectares, and substantially increased up to 1.026.922 hectares in 2010. The development of oil palm on peatland involve drainage that can disturb the capacity of peatlands in storing carbon. This literature study aims to assess the effect of drainage on carbon dioxide emissions of oil palm plantations on peatlands in Sumatera. Drainage of peatlands lead to an increase in carbon dioxide emissions. Separation processes in carbon dioxide emissions shows the contribution of peat decomposition, root respiration, plant biomass and fires for land clearing. Heterotrophic respiration (decomposition of peat) contributes 73% of the total soil respiration and the remaining 27% is from autotrophic respiration (root respiration).
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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