Judul: Komposisi Jenis Tumbuhan dan Simpanan Karbon Tegakan pada Area Rehabilitasi Greenwall Taman Nasional Gunung Gede Pangrango, Jawa Barat
Abstrak: Taman Nasional Gunung Gede Pangrango merupakan salah satu kawasan konservasi yang memiliki potensi tinggi sebagai penyerap dan penyimpan karbon. Salah satunya pada areal program rehabilitasi Greenwall, di Resort Nagrak TNGGP. Penelitian ini bertujuan untuk menganalisis komoposisi jenis, dan simpanan karbon tegakan pada areal rehabilitasi Greenwall, serta korelasi antara konsentrasi karbon dengan beberapa parameter ekologi. Metode yang digunakan adalah analisis vegetasi dengan purposive random sampling. Ukuran plot 20 m x 20 m sebanyak 3 jalur per tahun penanaman (2008, 2009, dan 2010). Komposisi jenis pada kawasan ini didominansi oleh jenis Schima wallichii, Agathis dammara, dan Syzygium polyanthum. Total simpanan karbon tegakan pada plot penelitian sebesar 103,44 ton/ha dengan kontribusi tertinggi berasal dari tingkat pertumbuhan pohon (96,38 ton/ha). Korelasi antara konsentrasi karbon dengan LBDS (luas bidang dasar) dan jumlah jenis menunjukkan korelasi yang kuat dan signifikan.
Keyword: forest carbon stock, rehabilitation, species composition

Judul: Correlation of Carbon Stocks with Vegetation Density Based on NDVI in the Rehabilitation Zone of Gunung Halimun Salak National Park
Abstrak: Kenaikan konsentrasi Gas Rumah Kaca (GRK) dan emisi karbon merupakan faktor yang berkontribusi besar terhadap perubahan iklim global. Taman Nasional Gunung Halimun Salak (TNGHS) merupakan salah satu kawasan konservasi yang berpotensi dalam mengurangi dampak perubahan iklim melalui peningkatan cadangan karbon. Penelitian ini bertujuan untuk menganalisis kerapatan dan tingkat keanekaragaman vegetasi, menduga potensi biomassa dan cadangan karbon tersimpan di atas permukaan tanah, serta menganalisis hubungan antara nilai NDVI dengan jumlah jenis, kerapatan pohon, keanekaragaman vegetasi, luas bidang dasar (LBDS), dan konsentrasi karbon. Metode yang digunakan analisis vegetasi, sedangkan pendugaan karbon menggunakan pendekatan alometrik dan destruktif untuk tingkat semai dan tumbuhan bawah. Plot yang dibangun berukuran 50 m × 50 m sebanyak 14 plot. Berdasarkan hasil analisis NDVI, kelas kerapatan terbagi menjadi kelas 1 (0,321–0,485), dan kelas 2 (0,485–0,746). Komposisi vegetasi di zona rehabilitasi TNGHS terdiri atas 103 jenis tumbuhan dan didominasi oleh rasamala (Altingia excelsa). Rata-rata biomassa dan konsentrasi karbon berdasarkan kelas kerapatan yang diperoleh masing-masing sebesar 296,55 ton/ha dan 139,38 ton/ha. Konsentrasi karbon memiliki korelasi kuat dengan LBDS (r = 95,5%). Nilai NDVI berkorelasi paling tinggi dengan kerapatan pohon per hektar., Increasing greenhouse gas concentrations and carbon emissions contribute greatly to global climate change. Gunung Halimun Salak National Park (GHSNP) is a conservation area with the potential to reduce the impact of climate change through increasing carbonreserves. This research aimeds to analyze the vegetation density and diversity, estimate the potential for biomass and carbon reserves and analyze the relationship between NDVI values and number of species, tree density, vegetation diversity, basal area (LBDS), and carbon concentration. The method used was vegetation analysis, while carbon estimation used an allometric for stake, pole and tree levels. Destructive approach for the seedling and understory levels. The plots that were built were 14 plots measuring 50 m × 50 m. Based on the results of NDVI analysis, density classes are divided into class 1 (0.321–0.485), and class 2 (0.485–0.746). The vegetation composition in the TNGHS rehabilitation zone consists of 103 plant species and is dominated by rasamala (Altingia excelsa). The average biomass and carbon concentration based on density class obtained were 296,55 tonnes/ha and 139,38 tonnes/ha respectively. Carbon concentration has a strong correlation with LBDS (r = 95.5%). NDVI values correlate higher with tree density per hectare variable than other variables.
Keyword: emisi karbon, biomassa, keanekaragaman vegetasi, perubahan iklim

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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