Judul: Pemanfaatan limbah penebangan menjadi arang untuk media tanam: studi kasus di PT. Austral Byna, Provinsi Kalimantan Tengah
Abstrak: Forest harvesting is extraction of forest products, timber and non-timber to be used. This activity relates with logging which generate waste of the cutting area with large enough in quantity. The big potential of timber waste which is big enough could be used rather than left in the forest. One of timber waste utilization is to make charcoal as the plantation medium. This is an effort to help overcome problems of marginal land in Kalimantan, which is dominated by red-yellow podzolic soil. Timber waste is used to produces charcoal through the combustion method pirolysis. Then charcoal and soil were mixed for geting ideal composition to be used as plantation medium. The composition of soil and charcoal mixture are given into polybag plantation medium size 10x15 cm with charcoal addition that is equal to 0%, 10%, 20% and 30%. Sengon were chosen as indicator of plantation growth because associated as fast growing species that could in different soil types, with simple silvicultural techniques. Charcoal addition significantly increased the growth on height, diameter, seedling dry weight and sturdiness of sengon seedlings. From the results of Completely Randomized Design (CRD) found that 10% charcoal addition into the plantation medium increased height by 37.15% compared to control, 30% the addition of charcoal increased 81,66% diameter compared to control. Total value of dry seedling weight in the end of the observation increased by 204.76% compared with control on the 10% charcoal addition. Value sengon seedling plantation medium 30% addition charcoal is 4,90 and the best in robustness compared to other seedlings. Charcoal addition of 30% were the suitable mixture of media for planting at nursery. Charcoal addition into the plantation medium increased sengon seedling growth, because charcoal contains nutrient elements wich could enhance the seedling growth. Moreover, the charcoal improve the texture of the polybag plantation medium in order to store the nutrients that plants need for growing well.
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Judul: Pendugaan Kandungan Karbon pada Tegakan Akasia (Acacia mangium) dan Sengon (Paraserianthes falcataria) di Lahan Reklamasi Pasca Tambang Batubara PT Arutmin Batulicin, Kalimantan Selatan
Abstrak: Indonesia has a vast landscape and abundant natural resources, both renewable and non renewable. Mining is an activity that utilizes the natural resources and potentially change the landscape, so that reclamation should be made as an effort to ensure appropriate land use designation. Reclamation of land by planting trees that will be a forest in the former mining area. Acacia (Acacia mangium) and Sengon (Paraserianthes falcataria) are fast growing species that can be planted on landfill. In addition, Acacia and Sengon also has a function as carbon storage. Acacia and Sengon on land reclamation deliver various carbon savings, so a study on the estimation of carbon stocks of Acacia and Sengon on land reclamation after mining of coal with biomass approach is needed. The research was carried out in reclamation forest of Acacia and Sengon post coal mining in Batulicin, South Kalimantan. Material used is reclamation forest of Acacia and Sengon planted in the post coal mining land in Batulicin, South Kalimantan, since 2005 with 3x4 m planty distance. The tools used in this study including scales, plastic rope, 30 m measuring tape, phiband, knives/machetes, plastic bags, newspapers, cameras and stationery. In both stands 5 plots measuring with 20x20 m plant spacing is made. Then in each corners of the plots a smaller used plot of 4x2x2 m is made for under storey and litter analysis and sample taking. Data acquired is processed though biomass approach then converted to carbon storage in ton/ha. To study the factors that affecting the carbon storage LSD analysis and ANOVA is used. Result shown by this study reveal that carbon storage in Acacia study is greater compared with that in Sengon stand. Carbon storage in Acacia stand is 71,864 ton/ha, while carbon storage in Sengon stand is 31,8853 ton/ha. The carbon storage difference in both stand is affected by tree species. Under storey and litter also the effect of biomass difference in each stand. Based on that data can be concluded that carbon storage potential in reclamation site of PT. Arutmin Batulicin with Acacia study is 117,8695 ton/ha, while carbon storage potential in Sengon study is 31,8853 ton/ha. Acacia vegetation resulting highest carbon content among other vegetation and litter vegetation in Acacia produced higher carbon content compared with litter vegetation in Sengon stand, mean while under storey in Sengon forest resulting higher carbon content compared with under storey vegetation in Acacia stand.
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Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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