The importance of inspection paths

Planning to measure

Conifer forests are planted at quite close spacing so that over time adjacent trees join together and draw each other up while minimising branch size. Lower branches eventually die due to lack of light but they remain attached to the tree making access to the forest difficult.

Good access is essential. Inspection paths are used to comfortably gain access to a forest and allow for trees to be inspected and measured at various points in the forest.

Once inspection paths are in place, accurate assessment can be done on sample trees to get an estimate of tree stocking density per hectare, tree size and estimated timber volume. With this information, decisions can be made on the forest's future management; decisions with regard to the crops suitability to thin, the age of first thinning and putting an estimate on the future yield of the forest.

Inspection paths also allow access to potential timber buyers and harvesting contractors.

Timing

Inspection paths should be cut when the lower branches are dead. This usually occurs when conifers are ten to fourteen years of age. There is no advantage in cutting inspections too early as live branches are more difficult to cut and there may be a risk of curtailing growth by removing live branches.

Cutting inspection paths

Cutting inspection paths (or ‘brashing’) involves the removal of branches along two adjacent rows of trees to head height. It does not involve the felling of any trees. Paths should be straight and run along original planting lines.

Paths should be cut every 50 metres (this equals every 100 rows) or every 100 metres in larger forests. Paths should link up to ensure easy access to all parts of the forest. It's easy to get lost - bringing a compass is a good idea.

It is important not to leave any pegs but also not to damage the tree's bark. 

Equipment and safety

In small areas, paths can be cut very effectively using a small handheld pruning saw. A small chainsaw can be used in larger forests (please note the following section on equipment and safety) .

When using a handheld pruning saw, you should use a suitable pruning saw, protective gloves, a helmet with visor and have a f irst aid kit with you.

Aim for a clean cut avoiding damage to the bark without leaving a peg. Pegs will result in an internal defect in the most valuable part of a tree.

As visibility is low within an unthinned forest; using a chainsaw for cutting inspection paths is particularly dangerous. Begin by cutting to head height along one side and complete the inspection path by returning on the adjacent line. It is acceptable to leave small pegs to avoid damaging bark.

The following is essential good practice for cutting inspection paths with a chainsaw:

• Chainsaws should only be operated by a trained operator
• Operator should wear a complete set of Personal Protective Equipment
• Only use a well maintained and suitable chainsaw
• Operator must have full and appropriate insurance cover
• Never allow the body of the saw above shoulder height
• Cut branches in a downward movement to avoid kickback of the chainsaw

Cutting of inspection paths is an essential operation in conifer crops.
Once completed, inspection paths provide clear and easy access into and through the forest, so that growth can be monitored, the timber crop assessed and provision made for timber harvesting and marketing. This puts the forest owner in a strong position to sustainably manage and optimise a forest crop.