Judul: The Effect of Canopy on Growth of Dryobalanops lanceolata Burck. in The Age at KHDTK Haurbentes, Jasinga
Abstrak: Jenis-jenis Dipterocarpaceae menjadi andalan dalam produk-produk hasil hutan berupa kayu pertukangan. Upaya melestarikan jenis-jenis Dipterocarpaceae, maka Badan Penelitian dan Pengembangan telah membangun Hutan Tanaman koleksi Dipterocarpaceae seluas 60 ha di Kawasan Hutan Dengan Tujuan Khusus (KHDTK) Haurbentes, Kabupaten Bogor, Provinsi Jawa Barat. Penelitian ini bertujuan untuk mengetahui persentase tutupan tajuk yang optimal dan karakteristik lingkungan yang tepat untuk pertumbuhan D. lanceolata. Data primer didapat dengan melakukan pengukuran dan pengamatan terhadap pertumbuhan D. lanceolata berupa diameter setinggi dada, tinggi pohon, tingkat tutupan tajuk dan kondisi lingkungan (temperatur dan kelembaban). Data sekunder berupa data pertumbuhan awal saat D. lanceolata baru ditanam dan kondisi umum lokasi penelitian. Pertumbuhan diameter dan tinggi D. lanceolata dipengaruhi oleh tutupan tajuk namun memiliki korelasi yang rendah. D. lanceolata dapat tumbuh pada rentang persentase tutupan tajuk sebesar 40% - 65% dan akan tumbuh dengan optimal apabila persentase tutupan tajuk dibawah 65%., Dipterocarp species are the mainstay of forest products in the form of carpentry wood. In an effort to preserve the Dipterocarpaceae species, the Research and Development Agency had established a 60 ha collection of Dipterocarp Forest Plantation in forest area with special purpose (KHDTK) Haurbentes, Bogor Regency, West Java Province. This study aims to determine the percentage of optimal canopy cover and appropriate environmental characteristics for the growth of D. lanceolata. Furthermore, primary data were obtained by measuring and observing the growth of D. lanceolata in the form of diameter at breast height, tree height, canopy cover level and environmental conditions (temperature and humidity). Meanwhile, secondary data, which was in the form of initial growth data when D. lanceolata, was newly planted and the general condition of the study site. The growth of diameter and height of D. lanceolata was influenced by canopy cover but had a low correlation. In addition, D. lanceolata can grow in the canopy cover percentage range of 40% - 65% and it will grow optimally if the percentage of canopy cover is below 65%.
Keyword: canopy, diameter, Dryobalanops lanceolata, height, growth

Judul: Evaluasi Pertumbuhan dan Simpanan Karbon Tegakan Dryobalanops lanceolata Burck. Umur 6 Tahun di KHDTK Haurbentes, Jasinga, Jawa Barat.
Abstrak: Dryobalanops lanceolata merupakan salah satu jenis dipterokarpa yang kayunya bernilai ekonomi untuk kayu pertukangan. Jenis D. lanceolata menjadi salah satu jenis prioritas dalam rehabilitasi hutan alam tidak produktif dengan menerapkan sistem silvikultur Tebang Pilih Tanam Indonesia Intensif (TPTII). Sistem ini menerapkan penebangan dengan sistem tebang pilih dan penanaman pengayaan dengan penanaman jalur yang dikenal dengan teknik Silvikultur Intensif (SILIN). Penelitian ini bertujuan untuk menganalisis kondisi lingkungan yang optimal untuk pertumbuhan D. lanceolata dari aspek tutupan tajuk, kondisi fisik dan kimia tanah serta pertumbuhan tegakan dan cadangan karbon yang terdapat pada tegakan D. lanceolata pada umur 6 tahun. Penelitian dilakukan dengan menganalisis regresi antara tutupan tajuk dengan pertumbuhan diameter dan tinggi pohon, menganalisis kondisi fisik dan kimia tanah, menentukan riap rata-rata tahunan, dan potensi simpanan karbon tegakan. Hubungan antara persentase tutupan tajuk dengan diameter dan tinggi tegakan D. lanceolata di KHDTK Haurbentes berkorelasi nyata, namun memiliki koefisien determinasi yang rendah. D. lanceolata pada umur 6 tahun telah tumbuh baik pada tutupan tajuk kurang dari 34% (keterbukaan tajuk lebih dari 66%), mampu tumbuh pada tanah liat dengan pH yang masam. D. lanceolata pada umur 6 tahun telah mampu memperbaiki kandungan unsur hara yang ada di tanah. Di bawah tegakan D. lanceolata umur 6 tahun telah mampu memberikan perubahan yang signifikan terhadap peningkatan ketersediaan unsur hara tanah untuk kandungan C-organik, N total, dan K-tersedia. Riap rata-rata tahunan diameter tegakan D. lanceolata pada umur 6 tahun sebesar 1,88 cm/tahun dan riap rata-rata tahunan tinggi tegakan sebesar 1,72 m/tahun. Simpanan karbon pada tegakan D. lanceolata mengalami kenaikan dalam rentang 1 tahun sebesar 41,91%. Dengan demikian, D. lanceolata merupakan jenis yang potensial untuk merehabilitasi hutan tidak produktif., Dryobalanops lanceolata is one of the dipterocarp species whose timber is economically valuable for woodworking. D. lanceolata is one of the priority species in the rehabilitation of unproductive natural forests by applying the Tebang Pilih Tanam Indonesia Intensif (TPTII) silviculture system. This system applies logging with a selective logging system and enrichment planting with lane planting, known as the Intensive Silviculture technique (SILIN). This study aims to analyze the optimal environmental conditions for the growth of D. lanceolata from the aspects of canopy cover, physical and chemical conditions of soil and stand growth and carbon stocks contained in D. lanceolata stands at the age of 6 years. The research was conducted by analyzing the regression between canopy cover and the growth of tree diameter and height, analyzing the physical and chemical conditions of the soil, determining the average annual increment, and the carbon storage potential of the stand. The relationship between the percentage of crown cover and the diameter and height of D. lanceolata stands in KHDTK Haurbentes is significantly correlated, but has a low coefficient of determination. D. lanceolata at the age of 6 years has grown well at a crown cover of less than 34% (crown openness of more than 66%), able to grow on clay soil with acidic pH. D. lanceolata at the age of 6 years has been able to improve the content of nutrients in the soil. Under 6-year-old D. lanceolata stands, it has been able
Keyword: Dryobalanops lanceolata, karbon, pertumbuhan, tanah, tutupan tajuk

Judul: The Isolation of Silver (Ag) from Fixer Sludge with Electrolysis methode
Abstrak: with the variations concentration, electrode of carbon, and voltages. The aim of research are looking for the easiest and eficient electrolysis. Among of 272.79 ppm of silver (impurities) could be produced from electrolysis fixer which used 300 times maintain the film. For 400, 500, and 600 times electrolysis were produced recently 49.42, 137.04, and 55.22 ppm. Futhermore, it was increased to 220.00 ppm from 700 times. These were possible because of density the solutions. From the electrode of carbon, 68.2222 g Ag (impurities) could be processed from size 14 cm x 3 cm x 3 cm. The next results 41.2050 g and 43.7559 g from the sizes 16 cm x 3 cm x 3 cm and 18 cm x 3 cm x 3 cm. The reasoned of this part any faster reaction on the most litle electrode. By the way, from voltages variation, the processed showed that 47.4575 g of Ag (impurities) could be produced from 11 volt. It’s caused the bigest voltages are also the bigest kinetics power on the reactions. Sampel and product were analized by AAS. Consentration has potential to be indicator, because of the used 700 times was given trend high Ag (impurities) became increase optimally at 11 volt, and much sediment that is 47.4575 g. The best rendemen is 13.33%. The other finding is that the strength of the time and the voltages strongly enfluence the electrolysis shown by the bigger result on F(calculation) than that of the F(table).
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