Sustainable Forestry - Cut-to-Length Logging

Research has shown that CTL logging has clear benefits for the landowner who wants to profit from their timber but maintain the structural and biological integrity of their land.  Some of the benefits of the CTL methods identified by forestry researchers are: greater adaptability for use in small logging areas or partial cuts; the possibility exists to haul sawlog-length boles, minus their tops, that are destined for chip use; allows for on-site sorting versus hauling to an alternate location; the CTL harvester has a greater reach than the full-tree feller buncher, CTL equipment is narrower and more compact and there is greater maneuverability in the harvesting head. In addition, there is no roadside slash since it is left behind as a ground mat. Overall, existing natural growth is better protected and ground disturbance is less than what occurs with the common full-tree length skidder technique. The disadvantages of CTL equipment have been identified as: requirement for a major time investment in both classroom and on-site training; productivity can be hindered on small tree size stands or dense stands, resulting in higher costs; the complexity of the machinery increases maintenance needs. Furthermore, the existing investment in full-tree equipment is substantial, and switching to other equipment must be a carefully calculated decision.  

US Forest Service publications show that CTL has advantages for the logger. Advantages include: 1) more economical on small tracts of timber; 2) less total labor cost, since only two employees are needed; 3) less fuel consumption by machines; 4) easier to merchandise highest valued products from trees; 5) Cut-to-length systems range from lowest worker's compensation rates; 6) safe and comfortable work environment; and 7) minimal site and stand damage. Disadvantages include: 1) somewhat longer learning curve for operators; and 2) high initial cost of individual cut-to-length equipment.

The research is clear: the disadvantages of  CTL methods are mainly in the start-up costs and training and maintenance for the CTL equipment owner.  For the logger who has clients who have small tracts needing harvest or who want uneven-aged methods used, CTL is superior to traditional harvest methods. Once CTL equipment is available in an area, the benefits to the landowner are significant, with little to no downside.  The use of CTL equipment and methods produces timber and profits with much less adverse impacts to soils, water quality, wildlife and the remaining timber on the land.

A forwarder is a piece of equipment that carries logs from the stump to the trucks without skidding them along the ground. U.S. Forest Service research shows that this machine greatly reduces erosion and soil loss when compared to the traditional log skidder.

Skidders pull logs behind them, and as they move through the forest, the dragged logs tear bark off the trees that are left standing.  And a skidder must make many passes through the forest to carry out the same amount of timber as a forwarder does in one trip. When one wants to selectively log or thin a stand of trees, the use of skidders can damage and even kill many of the trees that are purposefully left standing.  That can drastically reduce the future value of the remaining trees, both biologically and economically.

Trails for log skidders and log trucks can cause massive erosion and damage. Skid trails throughout this clearcut cause erosion and act as funnels sending sediment down into the stream below.

Unlike a trail made by a log skidder which can tear up the ground and cause massive ruts, a forwarder trail causes little erosion. Further, adding limbs and other woody debris to the trail reduces rutting and compaction and adds nutrients to the soil, thus speeding up recovery time for the land.