Judul: Keragaman Genetik Pinus merkusii Jungh. et de Vriese Strain Tapanuli berdasarkan Penanda Mikrosatelit
Abstrak: Pinus merkusii of Tapanuli strain, which grows naturally in Tapanuli area to the south of Toba Lake, has decreased considerably due to intensive logging. This research aimed at investigating genetic diversity of strain Tapanuli Pine using microsatellite markers on its three populations, i.e. Dolok Tusam Timur, Lobugala, and Parinsoran. Leaf samples were extracted using combined CTAB (cetyl trimethyl ammonium bromide) and DNeasy plant mini kit, then amplified using seven specific microsatellite primers from P. merkusii Aceh strain, i.e. pm01, pm04, pm05, pm07, pm08, pm09a, and pm12. Those primers could amplify polymorphic fragments with different sizes than reported before. Estimation of genetic diversity parameters showed that Lobugala population has the highest heterozygosity (He = 0.4693) followed by Dolok Tusam Timur (He = 0.4614) and Parinsoran (He = 0.4316). Lobugala population was closely related to Parinsoran with 0.0617 genetic distance, and separated from Dolok Tusam Timur by 0.3798 genetic distance. Partition of genetic variation showed that 81% was found within population, and only 18% was among population
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Judul: Analisis perubahan tutupan lahan, struktur genetik dan kandungan biomassa karbon Pinus merkusii Jungh. et de Vriese strain tapanuli pada sebaran alaminya di Sumatera Utara
Abstrak: Pinus merkusii strain Tapanuli is currently considered as endangered because of declining population and habitat due to logging activity and land use changes. With recent development on carbon trade the natural populations of P. merkusii strain Tapanuli has the potential as carbon sink. The objective of the research were 1) To analyze the landcover changes in five locations of strain Tapanuli natural habitat, which occured in 1994, 2005, and 2011, 2) To analyze the genetic structure of those five natural populations using microsatellite markers 3) To formulate the allometric equation for carbon biomass estimation of strain Tapanuli. Five study locations in strain Tapanuli natural habitat were selected as follows: a) two protected forests, i.e. Dolok Tusam Timur and Dolok Tusam Barat, b) two open and cultivated area, i.e. Parinsoran and Lobugala village, and c). Mixed forests in Tolang hilly village. Analysis of land cover changes was based on Landsat imagery 7 ETM+ in 1994, 2005, and 2011. Microsatellite markers were generated from microsatellite primers developed previously on P. merkusii strain Aceh. Formulation of allometric equations was done using destructive sampling method combined with volumetric method. The results showed that 1) Land cover changes that occur in Tapanuli terrestrial ecosystem from 1994 to 2011 has led to increased extent of weeds-shrub land, and cause the site of natural populations of Tapanuli strain of P. merkusii into nutrient poor. The cumulative soil carbon stock in the five research sites are as follows: Dolok Tusam Timur 55,5 ton C/ha, Parinsoran 46,1 ton C/ha, Dolok Tusam Barat 65,8 ton C/ha, Lobugala 89 ton C/ha, dan Tolang 71,1 ton C/ha. 2) Heterozygosity levels of those populations were high, and Population of Parinsoran and Tolang into one group, Population of Lobugala into one grup. 3). The best allometric equation for estimation of biomass carbon content of P. merkusii strain Tapanuli as follows: allometric equation for above ground biomass is Y = 0,1900(DBH)2,2730; for below ground biomass is Y = 0,0283(DBH)2,4393 and allometric equation for total biomass estimation of P. merkusii strain Tapanuli is Y= 0,2451(DBH)2,2757, 3). Based on this equation the potential carbon estimated in five location of natural distribution of P. merkusii strain Tapanuli are as follows: Dolok Tusam Timur 187,8 ton C/ha, Parinsoran 48,9 ton C/ha, Dolok Tusam Barat 190,4 ton C/ha, Lobugala 93,2 ton C/ha, and Tolang 45,7 ton C/ha.
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Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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