Forest Thinning | forestry services

What is Thinning

Thinning is best described as the selective removal of inferior stems in order to favour the growth of the remainder better quality stems. It is a normal and essential part of most forest crop rotations, and is essential if crops are to produce the maximum number of high value logs and consequently increase profitability. Thinning is generally undertaken 2 to 5 times over a forest rotation depending on the productivity of the crop.

Why Thin?

It is essential that forest thinning be carried out correctly and on time. When done, the benefits of thinning for an owner are

The correct management of the crop
Tax-free revenue from timber sales
Increase in asset value of the remaining crop
Remaining trees increase in volume faster which allows clear felling to be completed as quickly as possible

Not thinning will result in a larger number of smaller sized trees per hectare with a significantly reduced value on clearfelling.

Clear felling is the harvesting of all marketable trees at the end of a forest rotation. This can vary from year 30 to 50 depending on species.

To find out when your crop is ready to be thinned contact Forestry Services Ltd. here

Planning for Thinning

Planning for first thinning should start when the crop is 10 years old. Inspection paths need to be cut to permit access to the crop to determine its productivity and its projected first thin year. Cutting an inspection path or ‘brashing’ involves removing the branches to head height between two lines of trees.

Forest roads need to be planned and a General Felling Licence applied for.

General Felling License

Tree felling is controlled through the 1946 forestry Act. Before an owner can thin a plantation a general felling license must be secured from the Forest Service of the Department of Agriculture. Forestry Services ltd. Ltd applies for these licenses on behalf of the owner. This license specifies how the thinning is to be completed, and any environmental conditions that must be adhered to.

Types of Thinning

There are many types of thinning, with the most common one being what is normally referred to as 1 in 7 plus selection. This means 1 in every 7 lines of trees is completely removed to facilitate access with inferior quality trees selected for removal in the intermittent lines. This is normally completed mechanically with motor manual (chainsaw operator) employed only on specific stands.

Mechanical thinning uses specialised harvesting heads, which are fitted to purpose built harvesters of standard excavators. (picture of harvester). The timber is then removed to the roadside by a forwarder, which is a specialised forest machine. (picture of forwarder)

In the past chainsaw harvesting combined with horse extraction of timber was common. This is now only used in exceptional cases.

To view current Irish timber price trends click here

To view projected returns from a well managed Sitka spruce crop click here

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Why Thin?

Planning for Thinning

General Felling License

Types of Thinning

Forest Thinning

What is Thinning Thinning is best described as the selective removal of inferior stems in order to favour the growth of the remainder better quality stems. It is a normal and essential part of most forest crop rotations, and is essential if crops are to produce the maximum number of high value logs and consequently increase profitability. Thinning is generally undertaken 2 to 5 times over a forest rotation depending on the productivity of the crop. Why Thin? It is essential that forest thinning be carried out correctly and on time. When done, the benefits of thinning for an owner are The correct management of the crop Tax-free revenue from timber sales Increase in asset value of the remaining crop Remaining trees increase in volume faster which allows clear felling to be completed as quickly as possible Not thinning will result in a larger number of smaller sized trees per hectare with a significantly reduced value on clearfelling. Clear felling is the harvesting of all marketable trees at the end of a forest rotation. This can vary from year 30 to 50 depending on species. To find out when your crop is ready to be thinned contact Forestry Services Ltd. here Planning for Thinning Planning for first thinning should start when the crop is 10 years old. Inspection paths need to be cut to permit access to the crop to determine its productivity and its projected first thin year. Cutting an inspection path or ‘brashing’ involves removing the branches to head height between two lines of trees. Forest roads need to be planned and a General Felling Licence applied for. General Felling License Tree felling is controlled through the 1946 forestry Act. Before an owner can thin a plantation a general felling license must be secured from the Forest Service of the Department of Agriculture. Forestry Services ltd. Ltd applies for these licenses on behalf of the owner. This license specifies how the thinning is to be completed, and any environmental conditions that must be adhered to. Types of Thinning There are many types of thinning, with the most common one being what is normally referred to as 1 in 7 plus selection. This means 1 in every 7 lines of trees is completely removed to facilitate access with inferior quality trees selected for removal in the intermittent lines. This is normally completed mechanically with motor manual (chainsaw operator) employed only on specific stands. Mechanical thinning uses specialised harvesting heads, which are fitted to purpose built harvesters of standard excavators. (picture of harvester). The timber is then removed to the roadside by a forwarder, which is a specialised forest machine. (picture of forwarder) In the past chainsaw harvesting combined with horse extraction of timber was common. This is now only used in exceptional cases. To view current Irish timber price trends click here To view projected returns from a well managed Sitka spruce crop click here