Judul: Analysis on Crown Health Assessment of Fabaceae in Bogor Botanical Garden
Abstrak: Kebun Raya Bogor (KRB) merupakan salah satu kawasan konservasi tumbuhan secara ex-situ dengan berbagai jenis koleksi tumbuhan yang didominasi oleh tumbuhan berhabitus pohon. Salah satu koleksi tumbuhan berhabitus pohon di KRB termasuk ke dalam famili Fabaceae. Kegiatan pemantauan dan perawatan pohon secara berkala menjadi hal yang penting untuk dilakukan. Hal tersebut dilakukan sebagai upaya memastikan kondisi kesehatan pohon dan mencegah kerusakan yang berujung pada kematian pohon, khususnya yang membahayakan keselamatan pengunjung. Penelitian ini bertujuan untuk mengetahui tingkat kondisi kesehatan tajuk pohon pada famili Fabaceae di KRB menggunakan metode Forest Health Monitoring (FHM). Sebanyak 44 diamati menggunakan parameter kondisi tajuk untuk mendapatkan nilai peringkat visual tajuk (VCR), indeks ukuran tajuk (CSI), dan indeks kerusakan tajuk (CDI). Hasil penelitian menunjukkan pohon pada famili Fabaceae di KRB memperoleh skor VCR 6 untuk kondisi tajuknya yang dikategorikan kedalam kondisi kesehatan tajuk sedang. Nilai rata-rata CSI dan CDI pada keseluruhan spesies sebesar 18,6 dan 29,6 yang menunjukkan sebagian besar individu pohon pada famili Fabaceae termasuk kedalam kategori tingkat kerusakan tajuk sedang., Bogor Botanical Garden (KRB) is an ex-situ plant conservation area with many plant types that dominated by tree. One of the family of trees collected in KRB is the Fabaceae family. Periodic monitoring and maintenance of the trees become essential to ensure the tree’s health condition and avoid damages leading to tree death or endangered the visitors. This research aims to estimate the level of crown health condition in Fabaceae family in KRB using forest health monitoring (FHM) method. A total of 44 trees were observed using crown condition parameters to gain the visual crown rating (VCR), crown size index (CSI), and crown damaged index (CDI). This research showed that Fabaceae family in KRB reveal the VCR score 6, indicated the medium health crown condition of tree. The average value of CSI and CDI in the whole species is around 18,6 and 29,6, shows that most of the Fabaceae family’s tree are categorized in medium damaged rate.
Keyword: Crown damaged index, crown health condition, crown size index, forest health monitoring, visual crown rating

Judul: Analisis Kondisi Kesehatan Tajuk Pohon pada Petak Tanam XII dan XIII di Kebun Raya Bogor
Abstrak: Kebun Raya Bogor (KRB) merupakan kawasan konservasi ex-situ tumbuhan yang memiliki berbagai koleksi tanaman yang ditanam di atas areal kebun seluas 87 hektar. Pohon sebagai obyek utama yang merupakan daya tarik KRB diharapkan terjamin kesehatannya melalui pengelolaan yang baik. Penelitian ini bertujuan untuk mengetahui kondisi kesehatan tajuk pohon pada petak tanam XI dan XIII di Kebun Raya Bogor menggunakan metode Forest Health Monitoring (FHM). Sebanyak 37 spesies individu diamati menggunakan parameter kondisi tajuk untuk mendapatkan nilai peringkat visual tajuk (VCR), indeks besar tajuk (CSI), dan indeks kerusakan tajuk (CDI). Hasil penelitian menunjukkan nilai skor VCR 5 yang didominasi oleh individu pohon dalam kategori kondisi kesehatan tajuk sedang. Nilai rata-rata CSI dan CDI pada keseluruhan spesies sebesar 22.87 dan 29.14 yang menunjukkan sebagian besar individu pohon termasuk kedalam tingkat kerusakan tajuk sedang., Bogor Botanical Gardens (BBG) is an ex-situ plant conservation area which has a wide collection of plants grown in a garden area of 87 hectares. Trees as the main object and the main attraction of the BBG are expected to be maintained in a healthy condition through proper management. This study aims to determine the health condition of tree crowns in planting plots XI and XIII of Bogor Botanical Gardens using the Forest Health Monitoring (FHM) method. A total of 37 individual species were observed using the canopy condition parameter to obtain crown visual ranking (VCR), crown size index (CSI), and crown damage index (CDI) values. The results showed that the VCR score of 5, indicated that trees crown in the area are mostly categorized moderate canopy health conditions. The average CSI and CDI values for all species were 22.87 and 29.14 which indicated that most of the individual tree’s crown were classified as moderately damaged.
Keyword: Bogor Botanical Gardens, Crown Damage, VCR, CSI, CDI

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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