Judul: Peranan Cacing Tanah sebagai Bioindikator Kesuburan Tanah pada Berbagai Tipe Tutupan Lahan di Dramaga Bogor
Abstrak: Rapid population growth accompanied by improved quality of life for the better cause of human dependence on natural resources increases. In a natural resource ecosystems, plants have an important role in maintaining the ecological functions of ecosystems natural resources through its ability to regulate micro-climate conditions, water management and soil fertility. Soil fertility is the ability of the soil provides nutrients for plant growth. In this case, the earthworm is one of the terrestrial ecosystem biotic factors that served to increase soil fertility. The role of earthworms are very important for the process of decomposition of soil organic matter significantly affect the soil fertility. Research aims: (1) determine the type of land cover in Dramaga, (2) identify and analyze the various types of plants on land cover, (3) analyzing the fertility of the soil on the following types of land cover history management, (4) identify the type and abundance suspect earthworms as indicators of soil fertility, and (5) examine the relationship of the abundance of earthworms in soil fertility and plant abundance. Research activities carried out in Dramaga, West Bogor District, West Java. The research lasted for 3 (three) months, from February to April 2013. At the study site was the interpretation of Landsat imagery to identify and interpret the land cover type (landuse) at the study site. Then on each type of land cover is an inventory / treatise against three research objects that is plants, earthworms and soil fertility. Sampling design of the study using a two stage sampling. Primary sampling units in the form of squares measuring 20 m x 20 m three units per land cover type plants to the minutes of the tree level. As for the minutes of the level of regeneration is made smaller squares by three squares units each measuring 2 m x 2 m for seedlings, 5 m x 5 m for sapling and 10 m x 10 m for the pole in each primary sampling unit. Being for the benefit of earthworms treatise made secondary sampling unit size of 1 m x 1 m by one unit per primary sampling unit. In this study the identification or interpretation of land cover types is done using ArcGIS 9 software on Landsat imagery in 2012. The analysis of vegetation data (density, frequency, dominance, importance value index) using analysis of vegetation (Misra, 1974) and species diversity are analyzed according to the Shannon-Wiener formula (Krebs, 1978), soil fertility by the Research and Development of the Agriculture Department of Agriculture, 2005 and estimate the abundance of earthworms in each land cover type calculation procedures used by two stage sampling design. Based on the results of processing of Landsat imagery in the study site using ArcGIS 9 software, there are five types of land cover that bare ground, grasses, shrubs, forest plantations, and mixed forest. Results of data acquisition fifth land cover types dominated by species of different plants, namely: Digitaria sanguinalis (L.) in grasses, Waltheria indica (L.) in the bush, in Tectona grandis plantations, as well as Mimosa pudica (undergrowth), Hopea bancana (sapling), Baccaurea racemosa (pole), and
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Judul: Kesuburan Tanah pada Hutan Wakaf Kampung Muara, Kecamatan Pamijahan, Kabupaten Bogor, Jawa Barat
Abstrak: Pengetahuan tentang karakteristik dan kualitas tanah perlu diketahui untuk menilai dan memantau kesuburan tanah. Penelitian ini bertujuan untuk menentukan status kesuburan tanah Hutan Wakaf Kampung Muara Bogor. Penelitian dilakukan dengan mengambil sampel tanah terusik di lapangan pada tiga tingkat kerapatan tajuk dan dilanjutkan dengan analisis di laboratorium. Setelah dilakukan analisis, selanjutnya dilakukan penilaian sifat kimia tanah dan penilaian status kesuburan tanah. Hasil analisis laboratorium pada kerapatan tajuk rendah, sedang dan tinggi menunjukan pH tanah masam (pH 5,23; pH 4,58; dan pH 4,44), C-Organik tergolong tinggi (3,56%; 5,21% dan 7,98%), kandungan P potensial tinggi (63,45 mg/100g, 20,70 mg/100g, dan 54,47 mg/100g) kandungan K potensial rendah (26,61 mg/100g, 7,11 mg/100g dan 13,37 mg/100g), KTK tergolong tinggi (36,67 cmol/kg, 26,34 cmol/kg dan 28,22 cmol/kg) dan kejenuhan basa sangat rendah (24,57%, 6,30% dan 4,57%). Berdasarkan hasil analisis, status kesuburan tanah pada lokasi penelitian tergolong rendah., The knowledge of quality and characteristics of soil is a vital information for soil assessment and monitoring. This research is aiming to determine the soil fertility in Bogor Waqf Forest Kampung Muara. The research was conducted by collecting disturbed soil samples in three levels of canopy, and followed with laboratory analysis. After the samples are analyzed, an assessment of soil’s chemical properties and an assessment of soil fertility status were enacted. Results of Laboratory analysis on low, medium and high canopy density showed acidic soil pH values (pH 5,23; pH 4,58; and pH 4,44), C-Organic classified as high (3,56%, 5,21% and 7,98%), potential P content classified as high (63,45 mg/100g, 20,70 mg/100g and 54,47 mg/100g), potential K content classified as low (26,61 mg/100g, 7,11 mg/100g and 13,37 mg/100, CEC was high (36,67 cmol/kg, 26,34 cmol/kg and 28,22 cmol/kg), and base saturation was very low (24,57%, 6,30% and 4,57%). Based on the results of the analysis, soil fertility status of Bogor Waqf Forest was relatively low.
Keyword: hutan wakaf, kerapatan tajuk, kesuburan tanah, sifat tanah, status kesuburan tanah

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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