Production Rates of Mechanized Tree Felling Operations at Sao-Hill Forest Plantation, Tanzania

Abstract

With the advancement of technology in forest operations, utilization of advanced machines in timber harvesting has been increasing in the last decades. However, in order to understand their contribution in harvesting operations, it is important to quantify their production rates. The findings will assist the development of timber harvesting plans. Therefore, this study was conducted at Sao-Hill Forest Plantation in Tanzania to determine time consumption and production rates of whole tree harvesting system using feller buncher. Regression models for predicting time consumption and production rates were also developed. The results showed that average productive felling time was 0.7 minutes per tree and production rates was 32.6 m³/h respectively. The production rates varied among tree size classes. For trees with diameter at breast height (dbh) of 10-19.9 the average production rates was 19.07 m³/h while for dbh class of 30-39.9 the production rate was 75.48 m³/h. Time consumption and production rates models were having Adjusted-R² of 50% and 56 % respectively. Their relative root mean square errors (RMSEr), computed based on the predictions from 10 - fold across validation results, were 28.69% and 45.37%, respectively. Applicability of the models should be limited within the ranges from which they have been developed.