Publikasi

The use of allometric models is determined by several factors including the quality of different growing places, different environmental factors, and differences in harvest time in an area. Differences in harvesting time will affect the production of eucalyptus leaves and twigs. This research aims to create an allometric model as an estimate for eucalyptus leaves and twigs at BKPH Subang. The research method for data collection was inventory using a square measuring plot of 20 m x 20 m. The data inventoried were the weight of eucalyptus leaves and twigs, branch-free height, base diameter (30 cm above ground level), and branch-free diameter. Data analysis uses linear and nonlinear regression to develop allometric models. Next, carry out model suitability tests using corrected determined determination (R2-Adj), residual sum of square (RSS), and model simplicity. RSE and AIC as well as model validation tests using NRMSE and MAPE. The best allometric model is in the form of a compound with the equation Y= 1.189 1.109Db. The compound allometric model with a branch-free diameter estimator is a model in the category suitable for use. It has an R2-Adj value of 0.702, a residual sum of square value of 27.14, and a standard error of 0.331. The RSE model suitability test value is 0.02 and the AIC is-239.1. Meanwhile, the NRMSE model validation test value is 32.12 and MAPE is 27.77. The best allometric model is in the form of a compound with the equation Y= 1.189 1.109 Db. The compound allometric model with a branch-free diameter estimator is a model in the category suitable for use. It has an R2-Adj value of 0.702, a residual sum of square value of 27.14, and a standard error of 0.331. The RSE model suitability test value is 0.02 and the AIC is-239.1. Meanwhile, the NRMSE model validation test value is 32.12 and MAPE is 27.77. ABSTRAK.

The fifth principles of Sustainable Forest Management of the Forest Stewardship Council (FSC) is to encourage the efficient use of forest products and services to ensure economic viability and a wide range of environmental and social benefits, and one of the criteria is to minimize logging waste. Therefore, identification, calculations, and monitoring of logging waste should be done. The purpose of this study were to know the potential of logging waste in logging area and to know the estimated volume of waste based on the Annual Allowable Cut (AAC). This research was carried out at PT Karya Lestari, Berau District, East Kalimantan. It was found that the highest percentage of waste was in the form of the main trunk canopy, followed by the branches, stump, twigs and the rest of the bucking. It was also found that there was quite strong positive relationship between the volume of felled trees with its logging waste volume, and the estimated volume of logging waste based on AAC was 40,623 m³ per year. This result shows that the potential logging waste is high and it is recommended for the company to do logging on trees with small volumes or lower diameter class (40-89 cm).

Forest harvesting still encounters many problems especially concerning impact to the residual stand and environmental damage. Implementing the reduced impact monocable winch and planning of good skid trails should have a positive impact on work efficiency as well as, reducing damage to the residual stand and soil during felling and skidding activities. Reduced impact logging (RIL) with a monocable winch (Pancang Tarik) system has been tried in several IUPHHKs and it can be concluded that RIL monocable winch system could be applied practically and reduce impact on residual stand and soil damage. Using this technology has many advantages, among others: cost efficiency, locally made, environmental friendly, and high local community participation. Application of the monocable winch system in reduced impact logging is an effort to reduce economical and environment damages when compared to conventional system of ground based skidding with bulldozer system. The aim of this research is to verify the efficiency (operational cost), effectiveness (productivity) and time consumption of monocable winch system. The results indicate that the implementation monocable winch system, has reduced the soil damage as much as 8% ha-1. The skidding cost with monocable system is Rp95.000 m-3. This figure is significantly cheaper if compare with ground base skidding with bulldozer system in which the skidding cost around Rp165.000 m-3.