Judul: Subsidence and Percentage of CO2 Emission from the Decomposition to Subsidence of Peatland on Palm Oil Plantations
Abstrak: The drainage system on peatlands is aimed to eliminate limiting factors that can inhibit the growth of oil palm plantations. On the other side, peatland drainage practices will cause peat subsidence and it is associated with CO2 emissions from peatlands. Subsidence method is one of the methods commonly used in the approach to calculate CO2 emissions. The peat subsidence process consists of consolidation, compaction, and decomposition. Previous research resulted in emission data of 100 tons CO2/ha/year, of which 92% of the subsidence is considered as decomposed peat, and 8% is the components of compaction, soil respiration (autotroph and heterotroph). The percentage of decomposition to compaction-consolidation in the previous study was overestimated. The research was conducted on the oil palm plantation of Koto Gasib Village, Siak Regency, Riau Province. From January 2019 to January 2020. The study was carried out on oil palm plantation blocks on peatlands that have been controlled drained with a canal system to maintain water levels. Observational data were collected from 6 subsidence stick, 3 dipwells, 3 peat profiles, and LiCor 8100A automatic chamber. The observation interval for the observation of bulk density, subsidence, C-Organic and ash content every 3 months, while for the water level using the monthly average and every 30 minutes for CO2 flux. Peat analysis was conducted at the Laboratory of Chemistry and Soil Fertility, Department of Soil Science and Land Resources, IPB. The purpose of this study were to observe the rate of subsidence of tropical peatlands in oil palm plantations at various ages of oil palm plants, and to determine the percentage of decomposition of peat material from the subsidence rate. Subsidence was measured at adjacent oil palm planting blocks at 9, 12, and 17 years of age, with a peat thickness of about 5 m, and the land had been drained for 10, 13, and 18 years, respectively (one year prior to planting). Peat decomposition (heterotrophic respiration) is considered as actual CO2 emission compared to the calculated emission from subsidence which is considered as potential CO2 emission from the calculation of the subsidence method. Analysis of peat fiber at the research site generally shows that the deeper the surface of the peat, the higher the fiber volume with the average fiber at a depth of 0-10 cm 25.3% and classified into hemic peat. The peat density analysis using the kubiena box showed that the average density of peat at a depth of 0-20 cm in the three blocks observed was 0.134 g/cm3. Peat ash content shows accumulation on the peat surface as a result of the decomposition process of peat material, with an average of 5.83% and 2.31% at depths of 0-10 and 10-20 cm, respectively. Meanwhile, the organic C content of peat showed an average of 55.64% at a depth of 0-20 cm. The average subsidence rate for oil palm plantations on tropical peatlands 10-18 years after controlled drainage is 2.47 ±0.76 cm/year. Peatland subsidence is higher in older oil palms due to higher plant load and root density. There is a bouncing back phenomenon or an increase in the peat
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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: Infeksi Virus Parainfluenza Pada Anjing
Abstrak: Virus parainfluenza anjing termasuk famili Paramyxoviridae, berbentuk pleomorf dengan ukuran bervariasi (bergaris tengah antara 100-500 nm), berpembungkus peka ether, berisi genom RNA dan secara serologis mempunyai kesamaan dengan virus SV-5 kera; dikenak sebagai salah satu kausa penting dari sindrom "kennel cough". Infeksinya dapat mengenai anjing semua umur yang belum pernah terinfeksi atau mendapatkan vaksinasi mengakibatkan gejala klinis ringan yang terbatas pada traktus respirasi atu infeksi yang secara klinis tidak memperlihatkan gejala nyata. Gejala klinis yang nampak setelah masa inkubasi (1-5 hari) terlewati berupa batuk yang tidak berat selama beberapa hari, berbagai tingkat tonsilitis dan pharyngitis dan kadang-kadang ditemukan kenaikan temperatur rektal antara 1-2 derajat C dari temperatur normal rat-rata. Anjing terinfeksi mengandung virus pada traktus respirasi bagian atas dan bawah serta limfonoduli sampai hari ke 9 setelah infeksi. Penyebaran virus antar anjing terjadi secara aerogen.
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