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.
 

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