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: Komposisi Jenis dan Struktur Tegakan Hutan di Cagar Alam Sibolangit, Sumatera Utara
Abstrak: Forest is an ecosystem that combines the interaction between biotic and abiotic factors. Ecologically, the formation of forest community formed gradually through the changing of the vegetation and habitat. Community of forest is a dynamic and always changing until it reaches a optimum stage. The growth of a tree species in a forest community is influenced by several factors, including climatic factors, edaphic, physiological and biotic factors. The changing in the factors mentioned previously will take effect on the vegetation structure and composition. Forest with a variety functions and benefits provide a tremendous influence both directly and indirectly to several aspects such as ecology, economic, and social. Utilization of forests can be well manage and reach the sustainably if the information about the forest condition are available. Sibolangit Nature Reserve which is located in Deli Serdang regency. The existence of the Sibolangit Nature Reserve with high biodiversity information still limited, therefore it is necessary needed to have a study of nature reserve in order to explore the benefits and potency of the nature reserve without disturbing the presence and preservation of the forest. Hence, we need a study to in the Nature Reserve Sibolangit of the forest, analyze species the composition, and structure. This research conducted from December 2008 until January 2009 using vegetation analysis techniques with the transeet methods. As preliminary, the transeet divided into plots of 20m x 20m to inventory the trees, 10m x 10m to analyze the pole, 5m x 5m to inventory the saplings, and the 2m x 2m to inventory the seedling. For the sampling unit it uses a sampling design in the form of systematic sampling with random start. Based on the results of observation, the seedlings and saplings dominated by Sono keling (Dalbergia latifolia). While for the poles and trees dominated by Angsana (Pterocarpus indicus). The diversity value in Sibolangit Nature Reserve classified as medium diversity. In Sibolangit Nature Reserve, the highest Similarity Index values was found in the north-south slope and the lowest one found in north-eastern slopes. Forest vegetation Sibolangit Nature Reserve in vertical point of view consists of three strata, namely the stratum A (tree height over 30 meters), stratum B (tree 20-30 meters high), and stratum C (tree height 4- 20 meters), where most of the tree population is distributed in the canopy stratum from 11 until 20 meters. All individuals in the forest show clustered distributed at both the tree and forest regeneration level.
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Judul: Peluang Partikel Plasma Berada Pada Dimensi Debye Akibat Gangguan Gelombang Elektromagnetik dengan Menggunakan Persamaan Schrödinger
Abstrak: The solution of Schrodinger equations with plasma Coulomb potential in spherical coordinat results solution wave function and energy plasma particle. Electron probability density at Debye length with thermal effect same as ion, which indicates plasma in neutral state. Electromagnetic waves perturbation of an electric field given to result wave function perturbation system. The probability density of plasma particle due to electromagnetic waves perturbation is the largest when an electromagnetic waves frequency 1.41 times the plasma frequency .
Keyword: Schrödinger, plasma, electromagnetic wave