Judul: Ektomikoriza Pinus merkusii di Bagian Kesatuan Pemangku Hutan (BKPH) Lembang
Abstrak: Pinus merkusii in BKPH Lembang conservation forest was associated with ectomycorrhizal fungi which produced 4 root tip morphotypes. They were irregular pinnate, dichotomous, monopodial, and coralloid. Irregular pinnate was dominant morphotype observed with occurrence frequency of 72,5%. The four morphotypes were developed by three fungal orders belong to Boletales, Russulales and Tuberales. Boletales produced two morphotypes, irregular pinnate and coralloid, whereas Russulales and Tuberales produced dichotomous and monopodial morphotypes, respectively. One ectomycorrhizal fungus was sucessfully isolated from P. merkusii ectomycorrhizal root tip. Based on morphological and molecular analysis, the isolated fungus was identified as Cenococcum geophilum. The soil properties of BKPH Lembang were acidic soil containing very low P and Ca, and low Mg and K.
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Judul: Morfotipe Ektomikoriza Famili Dipterocarpaceae dengan Metode Lubang Bor di Hutan Penelitian Haurbentes, Bogor
Abstrak: In Indonesian, Dipterocarpaceae grows in nutrient-poor and acidic soils which usually characterized by low rates of organic matter decomposition, due to it’s selective advantage of ectomycorrizas association. This research aimed to study ectomycorrizal root tip morphotypes in Haurbentes conservation forest, Bogor. The root tip morphotype was determinited by observation of root branching pattern, colour, mantle, and rhizomorph. One hundred ninety one root tips from 48 core samples derived from 8 spesies of Dipterocarpaceae were observed for root colonization and morphotype. Data showed that roots of all plant species were colonized by ectomycorrizas with the average value 34.72% or 2.15 x 102 cm. They produced 12 different morphotypes. They were unramified-simple black straight, unramified-simple black bent, unramified-simple cream colored bent, monopodial pyramide brown straight, monopodial pinnate black tortuous, monopodial pinnate brown straight, monopodial pinnate brown bent, monopodial pinnate brown tortuous, irregularly pinnate black tortuous, irregularly pinnate brown tortuous, irregularly pinnate brown bent, and irregularly pinnate cream colored bent. The highest value of root colonization abundance was observed from irregularly pinnate brown morphotype (32.54 %), while the lowest was found in monopodial pinnate black tortuous (0.37 %).
Keyword: Root tips morphotype, Haurbentes conservation forest, Ectomycorrhizas, Dipterocarpaceae

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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