Factors affecting productivity of machined logging in thinning using small size forest machines

Abstract

The aim of the research is to find out changes in productivity depending on the diameter of the tree to be cut as well as the most important factor influencing the reduction of productivity using small size forest machines in thinning in Latvia. The equipment used in the study-both the harvester and the forwarder is Vimek. The results of the research confirm the appropriateness of the exact technique in thinning if diameter of the harvested trees is 3 to 30 cm. The average productivity of the harvester achieved with a harvester head Keto Forest Eco (option 2) in Norway spruce stands with 8 cm weighted average tree reached 9.59 m 3 h-1 , in deciduous tree stands with 9 cm weighted average was 10.17 m 3 h-1 , but in Scots pine stands with 12 cm average weighted tree diameter reached 10.19 m 3 h-1. By using the Keto Forest Eco Harvester head according to the thinning productivity figures, no significant difference among the tree species was detected. For the forest owner to predict the theoretical productivity of the harvester, it is possible to apply the equation R = K + KD * D, that is statistically significant, R 2 =0.85. This equation is applicable to thinnings when the diameter of thinned trees is between 4 and 25 cm. Forwarder's average productivity in thinned stands is 8.63 m 3 h-1 .

Complex forest management system based on small size forest machines

“…This is due to a rapid reduction in productivity with the diameter of the felled tree increasing over 22 cm. Similar conclusions concerning the equipment suitable to the tree diameters have also been obtained from the previous studies [8]. Undoubtedly, this does not prevent from sawing of larger dimension trees, since the harvester head can maximally handle stems with a diameter of up to 32 cm (at the root collar).…”

“…[8]. The notes specify the reasons for work breaks and other activities that do not match the work time elements specified in the table.…”

Operational Costs of Mid-Performance Forwarders in Czech Forest Bioeconomy

“…Therefore, prior to any economic analysis, analyzing the operation of a machine is suggested, from which, economic costs are inferred. Many authors focused on predicting or explaining the productivity of forest machinery [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. The accuracy of the analyses is increasing, as they no longer rely on manual measurements and limited data, but rather on the abundant data from the on-board forest machine systems [15,20].…”

“…Productivity of forwarders depends on factors such as mean volume of forwarded stem (mean stem volume; MSV), forwarding distance, terrain conditions, harvesting intensity and type, machine performance class, its bunk capacity, and others [1,5,[7][8][9][10][11]17,19,[21][22][23]. Forwarders with a bunk capacity up to 3 m 3 are able to forward from 2 to 4.1 m 3 /MH, whereas those with approximately 12 m 3 bunks typically forward between 7.1 and 20 m 3 /MH [1].…”