Different extraction methods were studied in mixed beech and oak forests in north-western Turkey. The average extraction distance was 100 m (109 yd), and the slope ranged between 20 to 40%, averaging 30%. The average productivity for each system is as per the table below.
|Extraction machine||Productivity (m3/hour)|
|Hauling with farm tractor||2.8|
|Hauling with forest tractor||5.25|
|Extraction with skyline||10.09|
The greatest amount of time for each machine was the skidding time. The tractor became very expensive when extraction distances exceeded 150 m. Source: http://link.springer.com/article/10.1007/s11842-013-9239-1