Judul: Characteristics of Community Forest in The Village of Sukajaya Sub-District Pabuaran Sukabumi
Abstrak: Perencanaan pengelolaan hutan rakyat yang baik dan lestari membutuhkan pemahaman tentang informasi terkait karakteristik dan struktur tegakan hutan rakyat. Struktur tegakan yang dimaksud dalam penelitian ini yaitu struktur tegakan horizontal. Penelitian ini dilakukan di Desa Sukajaya Kecamatan Pabuaran Kabupaten Sukabumi. Penelitian ini bertujuan untuk memperoleh gambaran tentang karakteristik hutan rakyat di Desa Sukajaya berdasarkan karakteristik tegakan, karakteristik petani, komposisi jenis, dan struktur tegakan. Data yang diambil dalam penelitian ini diperoleh dari hasil pengukuran langsung terhadap tegakan dan hasil wawancara terhadap 15 responden petani pemilik lahan. Hutan Rakyat Desa Sukajaya menerapkan pola tanam campuran dengan pengaturan jarak tanam. Jenis pohon yang mendominasi lahan dari 15 responden petani hutan rakyat tersebut yaitu jenis mahoni (Swietenia mahagoni), sengon (Paraserianthes moluccana) dan kayu afrika (Maesopsis eminii). Struktur tegakan horizontal Hutan rakyat Desa Sukajaya menyerupai bentuk kurva huruf J terbalik, dimana hubungan antara jumlah pohon per hektar (y) dengan nilai tengah kelas diameter (x) dari gabungan 15 responden petani hutan rakyat dinyatakan dengan persamaan : y = 4.305,39e-0,16x. Secara umum, tegakan gabungan mengindikasikan bahwa tegakan didominasi oleh pohon-pohon berdiameter kecil (diameter < 25 cm), sedangkan keberadaan pohon-pohon berdiameter besar, sedikit., Good and sustainable community forest management planning requires an understanding of information related to the characteristics and structure of community forest stands. The stand structure referred to in this research is the horizontal stand structure. This research was conducted in the Village of Sukajaya Sub-District Pabuaran Sukabumi. This research aims to obtain an overview of the characteristics of community forests in the Village of Sukajaya based on stand characteristics, species composition, and stand structure. The data taken in this research were obtained from the results of direct measurement of the stands and the results of interviews with 15 respondents from landowners. Village of Sukajaya community forest applies a polyculture cropping pattern with spacing arrangements. The types of trees that dominate the land 15 community forest farmer respondents are mahogany (Swietenia mahagoni), silk tree (Paraserianthes moluccana), and African wood (Maesopsis eminii). The horizontal stand structure of the Village of Sukajaya community forest resembles the shape of an inverted J curve, where the relationship between the number of trees per hectare (y) and the mean diameter class (x) of a combination of 15 community forest farmer respondents is expressed by the equation : y = 4.305,39e-0,16x. In general, the combined stands indicated that the stands were dominated by small-diameter trees (< 25 cm diameter), while the presence of large diameter trees was few.
Keyword: Characteristics of community forest, species composition, horizontal stand structure

Judul: Karakteristik dan Struktur Tegakan Horizontal Hutan Rakyat Desa Cimanggu Kecamatan Cikembar Kabupaten Sukabumi
Abstrak: Informasi mengenai karakteristik dan struktur tegakan hutan diperlukan supaya hutan tetap lestasi. Struktur tegakan yang dimaksud adalah struktur tegakan horizontal. Penelitian ini bertujuan untuk memperoleh gambaran tentang karakteristik hutan rakyat Desa Cimanggu Kecamatan Cikembar Kabupaten Sukabumi berdasarkan karakteristik petani, komposisi jenis pohon, pola tanam, sebaran pohon, kerapatan dan struktur tegakannya. Data ini diperoleh berdasarkan pengukuran langsung dan wawancara terhadap 36 responden pemilik lahan. Pola tanam yang digunakan oleh petani di Hutan Rakyat Desa Cimanggu adalah pola tanam campuran dengan sistem pemanenan yang diterapkan yaitu sistem tebang butuh. Struktur tegakan gabungan pada 36 responden petani hutan rakyat Desa Cimanggu berbentuk huruf J terbalik dengan nilai R² sebesar 0,9658. Struktur tegakan pada semua lahan petani menggunakan pendekatan persamaan eksponensial negatif. Model dari struktur tegakan horizontal gabungan 36 responden dengan pendekatan persamaan eksponensial negatif dinyatakan dengan persamaan : y = 〖3.368,70e〗^(-0,805x). Jenis pohon yang ditemukan adalah jenis sengon (Paraserianthes moluccana), mahoni (Swietenia mahagoni), jati (Tectona grandis), kayu afrika (Maesopsis eminii), manglid (Magnolia champaca), puspa (Schima wallichii), jabon (Anthocephalus cadamba), suren (Toona sureni), matoa (Pometia pinnata), pulai (Alstonia scholaris), akasia (Acacia mangium), dan karet kerbau (Ficus elastica)., Information on the characteristics and structure of forest stands is needed so that the forest remains sustainable. The stand structure in question is a horizontal stand structure. This study aims to obtain an overview of the characteristics of community forests in Cimanggu Village, Cikembar District, Sukabumi Regency based on farmer characteristics, tree species composition, cropping patterns, tree distribution, density and stand structure. This data was obtained based on direct measurements and interviews with 36 respondents who own land. The cropping pattern used by farmers in the Community Forest of Cimanggu Village is a mixed cropping pattern with the harvesting system applied, namely the cutting and needing system. The combined stand structure of 36 respondents from community forest farmers in Cimanggu Village is in the shape of an inverted J with an R² value of 0,9658. The stand structure on all farmers' lands uses a negative exponential equation approach. The model of the combined horizontal stand structure of 36 respondents with a negative exponential equation approach is expressed by the equation: y = 〖3.368,70e〗^(-0,805x). The tree species found were silk tree (Paraserianthes moluccana), mahogany (Swietenia mahagoni), teak (Tectona grandis), african wood (Maesopsis eminii), manglid (Magnolia champaca), puspa (Schima wallichii), jabon (Anthocephalus cadamba), suren (Toona sureni), matoa (Pometia pinnata), pulai (Alstonia scholaris), acasia (Acacia mangium), and buffalo rubber (Ficus elastica).
Keyword: characteristics of community forest, horizontal stand structure, species composition

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