Judul: Struktur Tegakan dan Komposisi Jenis Tumbuhan Pada Zona Montana di Hutan Pegunungan Gunung Gede, Jawa Barat
Abstrak: Hutan Peguilunga~l Gunung Cede merupakan salah satu lcawasan hutan yang ada di Jawa Barat. Areal Gul~ungG ede merupakan areal hutan yang berfuungsi sebagai pellyallgga kehidupan, sumber plasma nutfall dan pelestarian keanekaragamatl tumbuhan dan satwanya serta area! pemanfaata~l secara lestari sumberdaya alam hayati beserta ekosistemnya. Tujuan pe~lelitian ini ulltuk mengetahui struktur tegakan dan komposisi jellis tumbuhan pada zona Montana (1500-2400 n~ dpl) hutan pegunungan Taman Nasional Gu~lullg Gede Pangrango. Hasil penelitian itli dihzrapltan dapat memberika~i gambaran lnel~ge~lkaai rakteristik komu~litastu mbuhan yang ada di 11uta11p egunungan Gunung Gede, sehingga dapat dijadikan masukan bagi pengelolaan Taman Nasional Gu~luilgG ede Pangrango, Jawa Barat. Pe~lgambila~dl ata dilakukan dengan analisis vegetasi dengall teknik kombinasi antara cara jalur dan cara garis berpetak , dimana untuk tingkat pol1011 dilakukan dengall cara jalur sedangkan untuk tingkat semai, pancang, dan tiang digunaltan cara garis berpetak.Petak contoh dibuat secara nested sampling, yailu 20 111 x 20 m untuk tingkat pohon, 10 m x 10 m untuk tingkat tiang, 5 nl x 5 111 ~ultuk tingkat pallcallg dan 2 m x 2 m untuk tingkat sernai. Hasil penelitian menul~jukkan bahwa jellis tumbuhan yang paling domillall adalah: 1. Tingkat semai : Ardisinfirliginosa dengan INP 21,lO % 2. Tir~gkapt ancang: Ardisia villosn dengan INP 17,80 % 3. Titlgkat tiang : Ficz~sr ibes dengan INP 26,96 % I 4. Tingkat pohon : Schinzn v~~nllichdiein gall INP 32,33 % Keanekaragarnan jenis di hutan pegunungan Gunung Gede tergolong sangat tinggi. Hal ini dapat ditunjukkan oleh nilai indeks keanekaragaman jenis (H) diatas 3,5 untuk senlua tingkat pertumbuhan, yang secara turut-turut (semai, pancang,tiang, pohon) adalah sebesar 3,G; 3,7;3,9;3,9. Pola dominansi jenis untuk setiap tingkat pe~-tumbuhan bernilai cukup kecil yang berarti bahwa di hutan pegunungail Gunuilg Gede tidak terpusat pada satu jellis tertentu saja. I-Ial ini didukung oieh nilai kenlerataan jenis yang hampir mendelcati i yang n1enunjuklcan meratanya pola penyebaran jenis yang ada dihutan pegunungan Gunung Gede. Ternyata pola penyebaran jenis tunlbuhan domillan pada hutan pegunungan Gunung Gede dalaln keadaail normal dan nlenyebar secara mengelompok Struktur horizontal tegalcan untuk selllua jenis luaupun jenis.dominan terlihat ballwa samakin besar ukuran diameter pol1011 maka semakin sedikit juilllah individu pohon.Bentuk larva struktur horizontal tegakan yang ada di hutan pegunungan Gunung Gede nleilgilcuti bentuk U I I I U ~d~a ri distribusi lcelas diameter berbentuk huruf "J" terbalilc. Dari l~asislt ratifikasi tajuk dapat diketahui bahwa sacara umum pola pelapisan tajuk yang ada di hutan pegunungan Gunung Gede terbagi dalam tiga slrata tajuk yaitu: stratum A (tinggi tajuk lebih dari 30 m), stratum B (20-30 m)dan stratum C ( 4-20 m). Untuk stratum A ditenlpati ole11 jenis Trenza orienlalis, Slonnen sigzcn, dan Podocarpus neriifolius. Stratunl B ulnulnnya ditenlpati oleh jenis Castanol~sis argentea dan Macaranga rhizinoides. Stratum C umumnya ditempati oleh jenis Macropa17ax dispernlu~nd an Sauruuia perzdzlla. Berdasarkan hasil penelitian ini, disarankan agar dilakukan penelitian lebih lanjut mengenai pengaruh faktor lingkungan terhadap keanekaragalnan jellis di hutan pegunungan Gunung Gede Jawa Barat.
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Judul: Komposisi Jenis dan Struktur Tegakan Hutan di Taman Nasional Gunung Ciremai, Jawa Barat
Abstrak: INTRODUCTION. The existence of forest as an ecosystem is important for life supporting system. This is because the forest produces various benefits, either in the form of services or goods which are very useful for life. In West Java, as in other parts of Indonesia, forests which are still having relatively good condition, are found only in conservation areas. One of the forest conservation areas which is relatively large is Gunung Ciremai National Park (TNGC). The TNGC constitutes a nature conservation area which possesses important ecological function as life supporting system for the surrounding ecosystem. However, information concerning the existing biodiversity in TNGC is still lacking. Therefore, there is a need for more studies to obtain information on biodiversity level and forest composition and structure in TNGC. METHODOLOGY. This study was conducted from August through September 2008 in altitude zones of < 1.000 m above sea level (asl) (lowland zone), 1.000 – 2400 m asl (montane zone), and > 2.400 m asl (sub alpine zone) in Gunung Ciremai National Park, West Java. This study was performed by using vegetation analysis technique which constitutes combination between strip method for tree stage vegetation inventory and plotted line method for forest regeneration inventory. To ease the inventory process, each strip was divided into plots of 20 m X 20 m for tree stage vegetation inventory, 10 m X 10 m for pole stage inventory, 5 m X 5 m for sapling stage inventory, and 2 m X 2 m for seedling stage inventory. Units of vegetation sample plot were placed in west and south slope directions at altitude zones of < 1.000 m asl, 1.000 – 2.400 m asl, and > 2400 m asl. In each slope direction, two sample units with strip length of 200 m and width of 20 m were established. Sampling units were placed in the field with sampling design of systematic sampling with random start. RESULTS AND CONCLUSION. Sub alpine zone exhibited the least number of species (11 species) at all growth stages, as compared with those of montane zone (62 species) and lowland forest zone (58 species). The number of species in the montane zone was relatively greater as compared with that of lowland forest zone. In lowland zone, the dominant species were huru meuhmal (Litsea tomentosa) at seedling stage (IVI 33,7 %), kileho (Saurauia pendula) at sapling stage (IVI 29,3 %), and pine (Pinus merkusii) at pole and tree stages (IVI 144,7 % and 112.8 %). In the montane zone, the dominant species were huru meuhmal (Litsea tomentosa ) at seedling stage (IVI 22,6 %), Litsea sp. at sapling stage (IVI 19,4 %), walen (Ficus ribes) at pole stage (IVI 32.6 %) and saninten (Castanopsis argentea) at tree stage (IVI 45,4 %). At sub alpine zone, the dominant species was plending (Leucaena glauca) at seedling and sapling stages (IVI 64 % and 76,4 %), cantigi (Vaccinium varingifolium) at pole stage (IVI 124,3 %), and jamuju (Dacrycarpus imbricatus) at tree stage (IVI 138,3 %). Index of species diversity (H’) for all elevation zones in TNGC were categorized as high
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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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