Judul: Analysis of Tree Crown Health in Planting Plot XXIVA at Bogor Botanical Garden
Abstrak: Kebun Raya Bogor (KRB) merupakan salah satu bentuk hutan kota yang memiliki visi menjadi kebun raya kelas dunia, terutama dalam bidang konservasi tumbuhan. Pohon sebagai obyek utama daya tarik KRB diharapkan terjamin kesehatannya sehingga memberikan rasa aman dan nyaman bagi pengunjung. Pengelolaan kesehatan ekologis diperlukan untuk memantau kesehatan pohon, dengan salah satu metode yang dapat digunakan adalah Forest Health Monitoring (FHM). FHM dapat digunakan untuk memantau dan menerangkan kondisi tumbuhan karena dapat menilai kesehatan hutan berdasarkan kesehatan pohon penyusun serta memberikan informasi terkait kondisi kesehatan hutan melalui penilaian indikator dan kuantifikasi parameter kesehatan hutan. Salah satu indikator yang dinilai adalah kondisi kesehatan tajuk. Penilitian ini bertujuan mengukur tingkat kesehatan kondisi tajuk pohon pada petak tanam XXIVA KRB dengan menggunakan metode FHM. Hasil penelitian menunjukkan pohon-pohon klaster plot FHM KRB pada petak tanam XXIVA memiliki Skor VCR sebesar 7 dengan kategori kesehatan tajuk baik. Klaster plot FHM KRB memiliki nilai rata-rata CSI sebesar 15,3 dan nilai rata-rata CDI sebesar 23,8. Terminalia sp. menjadi spesies dengan nilai CSI tertinggi sebesar 45,8 dan Artocarpus sp. menjadi spesies dengan nilai CDI tertinggi sebesar 55,0., Bogor Botanical Garden (KRB) is a form of an urban forest that has a vision to become a world-class botanical garden, especially in the field of plant conservation. Trees as the main object of KRB attraction are expected to be in healthy condition to guarantee a sense of security and comfort for visitors. Ecological health management is needed to monitor tree health; one of the methods that can be used is Forest Health Monitoring (FHM). FHM can be used to monitor and explain trees conditions because it can assess forest health conditions through indicator assessment and quantification of forest health parameters. One of indicator assessed is trees crown health. This study aims to measure the health level of tree crown conditions in the planting plot XXIVA of KRB using the FHM method. The results showed that the trees the FHM KRB plot cluster at planting plot XXIVA had a VCR Score of 7 with a good crown health category. The FHM KRB plot cluster has an average CSI value of 15.3 and an average CDI value of 23.8. Terminalia sp. became the species with the highest CSI value of 45.8 and Artocarpus sp. became the species with the highest CDI value of 55,0.
Keyword: forest health monitoring, health level, tree quality

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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