Judul: Studi potensi pemanfaatan soil seed bank dalam upaya mempercepat proses suksesi di lahan pasca tambang nikel PT. Inco Tbk, Sorowako, Sulawesi Selatan
Abstrak: PT INCO Tbk. melakukan kegiatan reklalamasi dan restorasi lahan setelah kegiatan penambangan telah selesai dilakulcan. Namun, lahan revegetasi pasca tambang pada umumnya memiliki keanekaragaman hayati yang rendah. Rekolonisasi jenis lokal sulit terjadi karena beberapa faktor diantaranya kondisi lahan yang tidak kondusif bagi berkembangnya jenis lokal dan jarak lahan yang terlalu jauh dari lokasi sumber benih. Untuk mengatasi ha1 itu, salah satu upaya yang dilakukan adalah dengan memanfaatkanp potensi soil seed bank yang terdapat di hutan alam. Soil seed bank tersebut dimaafaatkan dengan mengumpulkan soil seed bank dari hutan alam kemudian ditambahkan ke populasi yang sudah terbentuk. Penelitian dilakukan dalam dua tahap, tahap pertama diawali dengan menguji potensi soil seed bank dengan mengambil sampel soil seed bank di lima kawasan hutan yang tersebar di wilayah konsesi PT INCO Tbk. Pada masing - masing kawasan diambil empat titik sampel, dihitung jumlah benih dan dilakukan tes perkecambahan. Kemudian tahap kedua adalah aplikasi percobaan di lapangan. Rancangan percobaan yang digunakan adalah Rancangan Petak Terbagi dengan tiga kelompok percobaan dan factorial 3 x 2 yang diulang sebanyak tiga kali sehingga menliliki jumlah petak sebanyak 54 petak dengan ukuran masing - masing 5 x 10 m. Kelompok yang diambil adalah tiga tegakan dengan karakteristik berbeda yaitu lahan dengan penutupan tajuk 0% (Co), lahan dengan penutupan tajuk 30 - 40 % (C,), dan lahan dengan penutupan tajuk 70 - 80 % ((22). Perlakuan petak utama adalah faktor tanpa penggunaan soil seed bank (So) serta pengambilan soil seed bank di dua tipe hutan, yaitu hutan pionir (S1) dan hutan klimaks (S2), sedangkan Parameter yang diamati berupa jumlah jenis non pohon, jumlah individu non pohon, jumlah jenis pohon dan jumlah individu pohon. Data tersebut kemudian dibuat tabulasi kemudian diolah menggunakan rumus Indeks Kekayaan Margalef dan Indeks Keanekaragaman Shannon-Wiener dan diolah mengunakan program CoStat versi 6.31 1 dan perbedaan nilai tengah dianalisis dengan uji lanjut Duncan pada taraf nyata 5%.
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Judul: Evaluasi Tingkat Keberhasilan Revegetasi Lahan Bekas Tambang Nikel Di Pt Inco Tbk. Sorowako, Sulawesi Selatan
Abstrak: PT INCO has made a borrow and use agreement with the government to do mining activity in forest area. This mining activity has caused severe damage to the forest and the land. With full awareness and to fulfill obligation in borrow and use agreement, PT INCO has done rehabilitation to severely damage forest and lands due to its mining activity. An evaluation is needed to measure the succession rate of rehabilitation effort that has been done by PT INCO. This evaluation put an emphasis on vegetational and biological aspect, enabling to see how far the revegetation activity able to fulfill restoration purpose as mention in Permenhut Nomor 146/Kpts-II/1999 and to restore functions of a forest. Object of this research is forest stand resulted from revegetation planted in 1999-2007, 1985 and 1996. Some of the equipments been used in this activity are brunton compass, measuring band, Sunto clinometer, spherical densiometer, plastic rope. Vegetational analysis done by using 17,8 m diameter circle plot. For each planting year make 2-3 plots with range 50 - 100 meter between each plot, for some cases such as limited land one plot is sufficient enough. In it observation made to plant growth factor such as plant height, plant diameter, root development and crown covering. Another parameter that also observed are local species existances and wildlife presence. Growth percentage in revegetation area range from 95% to 100%. Plant composition are pioneer species as Sengon (Paraserianthes falcataria), Eukaliptus (Eucalytus eurograndis), Sengon Buto (Enterolobium macrocarpum)and local species as Trema (Melochia umbellata), Sandro (Sandoricum kacappeae) dan Uru (Elmerelia sp). This mean it is suitable with goverment rule. Root development, growth, litter decomposition, erotion and crown covering has shown improvement according to succession concept. Same thing happen to wildlife, introduction has happened to revegetation lands. Revegetation at PT INCO in some aspects has fulfill goverment´s criteria and indicator but this revegetation has not reform original forest structure and function as protected forest.
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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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