Scottish forestry and woodland news

Rackless Thinning

27 July 2014  post by Nick Marshall

Following on from last weeks post looking at reducing the negative impacts that can come from thinning (Single Rack Thinning – Longer Lasting Woods…) we have also recently been thinning some woods without cutting any access racks.

By using our narrow alpine tractor with a skidding winch on the back we are able to extract trees whole, between the existing rows of trees for processing outside the wood.  This has various advantages in that it leaves an even woodland cover, with no large breaks in the canopy, it is a truly selective thin, with no good trees having to be removed unnecessarily, the woodland floor is left clean, without the usual large volumes of brash which can be left and no large machinery needs to enter the wood.

This technique is great for sensitive or high wind risk sites where a low impact method is required.  It is also particularly good for woodlands with alternative uses such as high sporting access or amenity value, where a clean, open woodland is beneficial, as it leaves a tidy and easy to walk through site.  

Once the trees have been removed they can either be processed by hand or mechanically at the edge of the wood, or if access is good, they can be chipped whole with all the residue being sold.  

The process is shown in the pictures below…

  • Our alpine tractor with skidding winch removing whole trees from the woodland Our alpine tractor with skidding winch removing whole trees from the woodland
  • Trees are brashed and selected by hand, cut through at the base and left ready for extraction Trees are brashed and selected by hand, cut through at the base and left ready for extraction
  • Several selected trees from a row are then attached to the winch rope with chains Several selected trees from a row are then attached to the winch rope with chains
  • Before being pulled off their stumps and gathered behind the tractor using the winch Before being pulled off their stumps and gathered behind the tractor using the winch
  • The tractor can then drag them whole between the existing rows of trees to the edge of the wood The tractor can then drag them whole between the existing rows of trees to the edge of the wood
  • Outside the wood the trees are then processed to recover timber products or could be kept whole.  The timber is kept clean during extraction by all the branches Outside the wood the trees are then processed to recover timber products or could be kept whole. The timber is kept clean during extraction by all the branches
  • The finished product, a brighter woodland with an even thin, no large gaps in the canopy and a clean woodland floor The finished product, a brighter woodland with an even thin, no large gaps in the canopy and a clean woodland floor