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All Journal MANAJEMEN HUTAN TROPIKA Journal of Tropical Forest Management Jurnal Ilmu Pertanian Indonesia Jurnal Penelitian Kehutanan Wallacea Jurnal Manusia dan Lingkungan
Ujang Suwarna
Departemen Manajemen Hutan, Fakultas Kehutanan, Institut Pertanian Bogor, Jalan Lingkar Akademik, Kampus IPB Dramaga PO Box 168, Bogor 16680, Indonesia
Agriculture, Biological Sciences & Forestry Humanities Chemical Engineering, Chemistry & Bioengineering Environmental Science Social Sciences

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Erosi Tanah Akibat Operasi Pemanenan Hutan (Soil Erosion Caused by Forest Harvesting Operations) Ujang Suwarna; Harnios Arief; Mohammad Ramadhon
Jurnal Manajemen Hutan Tropika Vol. 15 No. 2 (2009)
Publisher : Institut Pertanian Bogor (IPB University)

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Abstract

Forest harvesting operation has been known as an activity that should be considered as the main cause of soil erosion. Indonesia, the second largest owner of tropical forest, should have a serious consideration to the operation.  Therefore, the study was conducted in logged over area of a natural production forest.  The objectives of the study was to examine level of soil erosion caused by forest harvesting operations and to analyze a strategy to control level of the erosion based on its influencing factors. The study showed that forest harvesting operations caused soil erosion.  Factors that influenced the high level of the erosion were high level of precipitation, lack on planning of forest harvesting operations, no applying treatment of cross drain and cover crop in the new skidding roads, no culture of carefulness in the operations, and low human resource capacity in applying environmentally friendly forest harvesting techniques. Keywords: soil erosion, forest harvesting, logged over area, skidding road
Estimation of Total Carbon Stocks in Soil and Vegetation of Tropical Peat Forest in Indonesia Ujang Suwarna; Elias; Istomo
Jurnal Manajemen Hutan Tropika Vol. 18 No. 2 (2012)
Publisher : Institut Pertanian Bogor (IPB University)

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Abstract

The study was conducted in the forest concession area of PT. Diamond Raya Timber, Riau Province, Indonesia. Measurement and calculation carbon stocks in soil and vegetation of tropical peat forest should be done accurately to anticipate carbon trading. The objective of the study is to estimate carbon stocks in soil and vegetation in 4 forest conditions. The study found that biomass and carbon stocks in the soil was 8 times higher than in the vegetation in primary forest condition, and 10 times in logged over forest and secondary forest condition. Carbon stocks in vegetation and soil were 189.45 ton C ha-1 and 1537.37 ton C ha-1 in primary forest, 161.76 ton C ha-1, and 1713.77 ton C ha-1 in logged over area, 139.05 ton C ha-1 and 1486.39 ton C ha-1 in secondary forest, and 43.09 ton C ha-1 and 1205.59 ton C ha-1 in degraded forest. Allocation of carbon stocks in the standing trees in primary forest, logged over area, secondary forest, and degraded forest were 70, 60, 62, and 7% respectively.
Pertumbuhan semai sengon dan mangium pada tanah padat Juang Rata Matangaran; Cahyo Wibowo; Ujang Suwarna
Jurnal Ilmu Pertanian Indonesia Vol. 15 No. 3 (2010): Jurnal Ilmu Pertanian Indonesia
Publisher : Institut Pertanian Bogor

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Abstract

The research was conducted to examine the seedling of mangium (Acacia mangium and sengon (Paraserianthes falcataria) on compacted soil. Soil was compacted with a proctor test at the different level of bulk density (0.9;1.0; 1.1; 1.2; 1.3 g/cm3 ) with 10 replications. The compacted soil was put into the plastic pot. After 6 month growth in pot the seedling growth response was measured.The result showed that the root penetration and seedling height linearly decrease with the increase of bulk density. The root of seedling of mangium (Acacia mangium and sengon (Paraserianthes fa/cataria) could not penetrate deeply at the hardest soil (1.3 g/cm3 ). Roots needs space to grow. The space was occupied by soil particles and soil pores. Root may influence chemical and physical properties of soil. In related to the compacted soil the root penetration is the important variable which is affected by the soil hardness. Under the condition of decrease penetration, seedling can not grew well in lack of nutrient to be absorbed by the root. On the other hand the bulk density 1.3 g/cm3 showed difference for seedling height response. However, the growth response was significantly reduced at the level of 1.3 g/cm3. The bulk density 1,3 g/cm3 was the critical limit of soil hardness for the seedling of Mangium and Sengon growth.
Ciri Limbah Pemanenan Kayu di Hutan Rawa Gambut Tropika Ujang Suwarna; Juang Rata Matangaran; . Morizon
Jurnal Ilmu Pertanian Indonesia Vol. 18 No. 1 (2013): Jurnal Ilmu Pertanian Indonesia
Publisher : Institut Pertanian Bogor

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Abstract

Effectiveness of timber harvesting in peat swamp forest is low. It is indicated by highly logging waste caused by timber harvesting operation. Thus, logging waste should be studied to describe characteristic and volume of logging waste in locations of compartment, landing, skidding track, and hauling road. The waste can be in the form of stumps, stems, and branches with diameter above 30 cm. Data of the waste was collected from 6 sample plots consisted of 3 plots in mechanized plots and 3 plots in traditional plots. Most of the waste found in location of compartment that caused by felling activities. Average volume of waste in traditional plots was 7.81 m3/ha that was found in location of compartment. The average volume of waste in the mechanized plots was 19.75 m3/ha, consisted of 16.90 m3/ha (85.57%) in location of compartment and 2.85 m3/ha (14.43%) in landing point. Logging waste can be minimized by providing appropriate training regularly and increase techniques of timber harvesting in the field.
Impacts of gap planting on soil density and erosion Elias Elias; Ujang Suwarna
Jurnal Penelitian Kehutanan Wallacea Vol. 8 No. 1 (2019)
Publisher : Foresty Faculty of Hasanuddin University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1149.01 KB) | DOI: 10.18330/jwallacea.2019.vol8iss1pp9-18

Abstract

By 2016, there were 32.70 million ha of degraded forests in Indonesia. If it isnot quickly rehabilitated, there will be land use changes and expansion of industrial forest plantation, which significantlyaffects itsbiodiversity and environmental. This research aims to study the impacts of the gap planting technique with red jabon on soil density and erosion. The research used: (1) the gap planting technique of red jabonwitha proportion of the total gap area to thetotal natural forest area of 40%: 60%, planting distance of 4m x 5m, and the number of trees planted of 200 stems/ha, (2) Digital-Humboldt Static Cone Penetrometer to measure soil density, and (3) stick for soil erosionmeasurement. The results showed that gap planting with red jabon to rehabilitate degraded natural forests increasedthe soil density, but itsvalue was categorized as a very loose soil class. On the other hand, the soil erosionin gap area was lower than in degraded natural forest area, because the condition of a part of the degraded forest was unvegetatedland, and there were the wastes of branches, twigs, and leaves as well as grown grasses on the soil surface that hinder the soil erosion in the gap area. This research concluded, that the impact of the gap planting on soil density can be neglected, and the impact of the gap planting on soil erosion is positive. Further research on social-economic, biodiversity, effective and efficiency aspects of the gap planting technique for forest rehabilitation are needed before its implementation
KERUSAKAN TEGAKAN TINGGAL AKIBAT PEMANENAN KAYU DI HUTAN ALAM RAWA GAMBUT (Residual Stand Damage Caused By Timber Harvesting in Natural Peat Swamp Forest) Ujang Suwarna; Juang Rata Matangaran; Febriangga Harmawan
Jurnal Manusia dan Lingkungan Vol 21, No 1 (2014): Maret
Publisher : Pusat Studi Lingkungan Hidup Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jml.18515

Abstract

ABSTRAKHutan rawa gambut memiliki fungsi sangat penting baik fungsi hidrologi, ekologi, ekonomi maupun sosial. Pada sisi lain, diduga bahwa kegiatan pemanenan hutan berpotensi dapat menurunkan fungsi tersebut. Oleh karena itu diperlukan pengukuran dan penghitungan secara akurat terhadap kerusakan tegakan tinggal di hutan rawa gambut di Provinsi Riau dengan tujuan untuk mengevaluasi implementasi kegiatan pemanenan hutan. Penelitian ini menemukan bahwa kegiatan pemanenan hutan menyebabkan terjadinya kerusakan tegakan tinggal berdiameter ≥ 10 cm sebesar 40% yang terdiri dari 20% akibat kegiatan penebangan pohon dan 20% akibat kegiatan penyaradan kayu. Kerusakan tegakan tinggal akibat pemanenan hutan dikelompokan menjadi kerusakan berat sebesar 77%, kerusakan sedang sebesar 14% dan kerusakan ringan sebesar 9%.    ABSTRACTPeat swamp forest has important functions consisted all aspects of hydrology, ecology, economic and social. Meanwhile, timber harvesting activities can potencially reduce some punctions of peat swamp forest.  Measurement and calculation on residual stand damage in natural peat swamp forest should be done accurately to evaluate implementation of timber harvesting in natural peat swamp forest and to estimate forest carbon stock.  The objective of the study is to measure trees damage in order to evaluate implementation of timber harvesting in natural peat swamp forest. The study was conducted in the forest concession area of PT. Diamond Raya Timber, Riau Province, Indonesia. The study found that the damage of trees > 10 cm caused by timber harvesting in natural peat swamp forest was 40%. It consisted of 20% caused by tree felling and 20% caused by timber skidding. The damage of trees > 10 cm caused by timber harvesting in natural peat swamp forest classified as heavy damage of 77%, moderate damage of 14%, and light damage of 9%.
Co-Authors . Morizon Cahyo Wibowo Elias Febriangga Harmawan Febriangga Harmawan, Febriangga Harnios Arief Istomo . Juang Rata Matangaran Mohammad Ramadhon