Judul: Pendugaan Biomassa, Karbon dan Serapan Karbon Dioksida Empat Jenis Tegakan di Hutan Pendidikan Gunung Walat
Abstrak: Hutan memiliki peranan penting dalam pengendalian pemanasan global dengan menyerap karbon dioksida (CO2) di atmosfer dan menyimpan karbon dalam bentuk biomassa hutan. Penelitian ini bertujuan menduga biomassa, simpanan karbon dan serapan karbon dioksida (CO2) pada empat jenis tegakan yakni agathis, puspa, meranti, dan kayu afrika di Hutan Pendidikan Gunung Walat. Pengukuran di lapangan berupa diameter pada semai, pancang, tiang, dan pohon. Plot contoh berbentuk persegi dengan ukuran 20 m × 20 m yang memiliki subplot-subplot untuk pengukuran semai, pancang, tiang, dan pohon. Analisis data pendugaan biomassa menggunakan persamaan alometrik biomassa. Kandungan karbon dan serapan karbon dioksida diperoleh dari konversi nilai biomassa. Hasil penelitian menunjukkan total biomassa agathis 14.646,77 ton/ha, biomassa puspa 6.436,02 ton/ha, biomassa meranti 91,31 ton/ha, dan biomassa kayu afrika 66,28 ton/ha. Karbon yang tersimpan pada agathis 6.883,98 ton/ha, puspa 3.024,93 ton/ha, meranti 42,92 ton/ha, dan kayu afrika 31,15 ton/ha. Serapan karbon dioksida agathis sebesar 25.241,26 ton/ha, puspa 11.091,41 ton/ha, meranti 157,36 ton/ha, dan kayu afrika 114,23 ton/ha., Forests have an important role in controlling global warming by absorbing carbon dioxide in the atmosphere and storing carbon in the form of forest biomass. This study aims to estimate biomass, carbon storage, and carbon dioxide uptake (CO2) in four types of stands namely agathis, puspa, meranti, and African wood in Gunung Walat Educational Forest. Measurements in the field in the form of diameters at various growth rates. The sample plot is a square with a size of 20 m × 20 m which has subplots for measuring seedlings, saplings, poles, and trees. Analysis of the biomass estimation data using the biomass allometric equation. Carbon content and carbon dioxide uptake were obtained from the conversion of biomass values. The results showed that the total biomass of agathis was 14.646,77 tons/ha, puspa biomass 6.436,02 tons/ha, meranti biomass 91,31 tons/ha, and african wood biomass 66,28 tons/ha. Carbon stored in agathis 6.883,98 tons/ha, puspa 3.024,93 tons/ha, meranti 42,917 tons/ha, and african wood 31,153 tons/ha. Carbon dioxide absorption of agathis was 25.241,26 tons/ha, puspa 11.091,41 tons/ha, meranti 157,36 tons/ha and african wood 114,23 tons/ha.
Keyword: biomassa, Gunung Walat, Hutan Pendidikan, karbon, karbon dioksida

Judul: Pendugaan Potensi Volume, Biomassa, dan Cadangan Karbon Tegakan di Hutan Pendidikan Gunung Walat Sukabumi Jawa Barat
Abstrak: The current global warming is caused by the increasing of greenhouse gases emitted to the Earth’s atmosphere. Greenhouse gases that affect directly is CO2 (carbon dioxide). If there are too many concentration of CO2 in the atmosphere, it will cause warmer temperature. Increasing the average temperature of Earth's atmosphere over the years led to climate change. The effort to solve climate change is conducting mitigation. One of the sectors that play a role in climate change mitigation is forestry sector. Forest able to absorb the excess carbon in the atmosphere and store it in the form of biomass in various parts of the plant (particularly timber) through the photosynthesis process. One of Indonesia's forests which has the potential carbon stocks is Gunung Walat University Forest (GWUF). This research aims to estimate the potential of volume, biomass, and carbon stocks in the forest which can be use as a basis for making the forest planning, management, and protection. Field data collected at the stands of Agathis lorantifolia (agathis), Pinus merkusii (pine), Schima wallichii (puspa), Maesopsis eminii (kayu afrika), and the others stand with the circle sample plot sized 0.1 ha. The stands volume estimated by using volume table equation and the biomass estimation by allometric models. Carbon stocks estimation obtained from biomass value that is converted to the carbon fraction (0.47). Data analysis in this research uses two methods, estimation without stratification through systematic sampling with random start and estimation with stratification through stratified sampling. Estimation with stratification is performed in two ways, stratification based on potential value and stratification based on the vegetation type. The result of potential estimation with stratification in GWUF more accurate then the method of estimation without stratification. The average volume of estimation with stratification based on its potential value is 399.45 m3/ha and the total volume is 142,832.56 m3; the average and total of biomass potential are 202.37 tons/ha and 72,363.70 tons; and then the of average of carbon stocks is 95.12 tons/ha and the total carbon stocks is 34,085.51 tons. While the estimation results with stratification based on the vegetation type shows the average and total volume are 398.29 m3/ha and 142,416.26 m3; the average of biomass potential is 202.82 tons/ha and the total of biomass potential is 72,522.35 tons; with average of carbon stocks is 95.32 tons/ha and the total carbon stocks is 34,085.51 tons.
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Judul: Query Expansion based on Bilingual Dictionary Using Conditional Probability
Abstrak: Query expansion is a technique that can be used to bridge vocabulary gaps between queries and documents in the collection. With query expansion, user will be helped to formulate queries well so that user will optimize the search result. In this study, the expansion term was resulted from the translation of bilingual dictionary. Subsequently, several terms of expansion were elected based on the closeness of its relationship with the original query. This research showed that conditional probability can be used to select expansion term in bilingual translation method query expansion. The result of 1000 documents was more than 97% relevan document can be retrieved by this system. The more expansion term used, the larger number relevan document was retrieved.
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