Judul: Pendugaan Cadangan Karbon pada Tegakan Rehabilitasi TOSO di Hutan Pendidikan Gunung Walat, Sukabumi, Jawa Barat.
Abstrak: Hutan berperan penting dalam mitigasi perubahan iklim karena mampu menyerap karbon dioksida (CO2) dari udara dan menyimpannya dalam bentuk cadangan karbon. Penelitian ini bertujuan untuk menduga cadangan karbon dan serapan CO2 yang tersimpan pada areal rehabilitasi TOSO di Hutan Pendidikan Gunung Walat (HPGW). Pengukuran cadangan karbon menggunakan 70 plot contoh yang dirancang dengan metode stratified systematic plot sampling with random start pada tahun tanam 2009–2015. Pada tiap plot contoh, cadangan karbon ditentukan berdasarkan cadangan biomassa yang diduga menggunakan model alometrik biomassa pohon dan metode konversi volume ke biomassa pohon. Hasil penelitian menujukkan bahwa tegakan di areal rehabilitasi TOSO tersebut menyimpan cadangan karbon sebesar 28.51 ton dengan selang kepercayaan 95% antara 21.97 hingga 35.06 ton. Hal ini berarti bahwa tegakan tersebut telah mampu menyerap CO2 sebesar 104.64 ton (dengan kisaran 80.63–128.66 ton) dalam kurun waktu 2009–2016.
Keyword: biomassa, cadangan karbon, HPGW, rehabilitasi hutan, serapan CO2

Judul: Pendugaan Serapan Karbon Dioksida di Areal Rehabilitasi Hutan Pendidikan Gunung Walat Sukabumi
Abstrak: Estimation of carbon dioxide (CO2) sequestration in rehabilitation areas is necessary to evaluate environmental benefits of a forest rehabilitation project. This study was aimed to estimate the CO2 sequestration of young stands in two rehabilitation project areas of Gunung Walat Educational Forest (GWEF), i.e. COPI and TOSO project areas. Field measurement was conducted to measure diameter and height of trees in 61 sample plots, which were established systematically in the rehabilitation project areas. Appropriate allometric models were used to estimate biomass and CO2 sequestration of each sample tree species. The population estimation of CO2 sequestration was conducted by applying two sampling methods, i.e. simple random sampling and stratified sampling. The results showed that by using stratified sampling the total CO2 sequestration of COPI area was 15.57 tons and that of TOSO was 13.22 tons. These estimates were more accurate than those of simple random sampling, which produced total CO2 sequestration of 13.45 tons for COPI and 13.47 tons for TOSO. Therefore, it can be concluded that estimation with stratification provided better results than without stratification.
Keyword: sampling method, forest rehabilitation, carbon sequestration

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.
Keyword: