Simulation of scenarios considering different stump and pre-bucking disc heights in mechanized timber harvesting operations in Pinus spp. stands after the fourth thinning

Abstract

This study aimed to quantify scenarios, considering different stump and pre-bucking disc heights, in order to search for alternatives to optimize the mechanized timber harvesting process in a Pinus spp. forest. In this way, the simulation of six scenarios was carried out after the fourth thinning. The situation defined by the company in its planning was considered and applied to scenario 1 (S1), with stump heights and pre-bucking disc heights of up to 15 cm and 10 cm, respectively. The scenario 2 (S2) included the real situation, that is, the measurements made in sample units installed on the field, scenario 3 (S3) included stump heights of 10 cm and pre-bucking disc heights of 5 cm and, in the other scenarios (S4, S5 and S6), stump and pre-bucking disc heights with values higher than the ones specified by the company were included. To that end, taper functions were used to quantify the assortments and the economic returns for each scenario. Results showed that scenario 3 presented the highest economic gain (5434.27 USD ha-1) followed by scenario 2 (5431.97 USD ha-1), surpassing the production expectations (S1). Therefore, the company must seek to improve and optimize the mechanized harvesting process by increasing investments for improvements in the planning of the operations, establishing measures throughout the production process and training the employees. These changes can reduce the non-conformities, expand revenues and result in better use of natural resources.