Forest fences – keeping our forests safe

If animals get into a young forest they can cause serious damage to small trees. Without the protection offered by fences from a range of domesticated and wild animals, our forests risk being damaged irreversibly - economically and environmentally. Forestry advisor Noel Kennedy has advice

(Main image above. Figure 1 - Deer fence)

We measure the success of our forests in terms of:

• timber production
• economic returns
• increasingly the environmental benefits.

If we take a step back however we may realise that there is one unsung element of the forest infrastructure that plays a critical role to enable our forests to realise this potential – our forest fences.

Without the protection offered by fences from a range of domesticated and wild animals, our forests risk being damaged irreversibly - economically and environmentally.

Risks to young forests

In a farming country like Ireland, young forests will more than likely neighbour land with cattle, sheep, horses and even goats. If these animals get into the young forest they can cause serious damage to small trees browsing their light stems, eating their delicate leaves and pulling up trees with undeveloped root systems.

In addition to the risks from livestock, wild animals can also pose a serious risk to both young and older trees. Hares and rabbits can cause extensive damage to small broadleaf trees but the biggest challenge to both conifers and broadleaves is from deer whose browsing and bark stripping is an increasing threat.

Protecting our young forests

DAFM’s Afforestation Scheme requires that all new forests are fully protected from the risks of animal damage and provides financial support towards fencing works.

In preparing an Afforestation grant application for pre-planting approval, a registered forester will assess the condition of the proposed planting boundary. This will include  existing fences/ditches, and if they offer adequate protection or stock-proofing from livestock.

Where boundary ditches are weak and gappy or where an existing wire fence is in poor condition the forester may conclude that the boundary is not stock-proof. New fencing and/or upgrading of existing fences may be required. The forester must also submit a fencing map with the afforestation grant application showing the proposed fencing works

Forest fence types

Depending on the level and range of risks identified in the forester’s assessment, there are number of forest fence type options available – on their own or in combination.

• Cattle – The most common forest fence type is designed to keep out cattle, horses and goats using three strands of barbed wire. Where a threat is exclusively from horses, consideration may be given to using plain instead of barbed wire.
• Cattle/Sheep – Designed to keep out sheep and cattle with 1 metre high sheep wire and 1-2 strands of barbed wire on top.
• Cattle/Rabbit – Designed to keep out rabbits and cattle with a standard cattle fence plus 1.2 metre rabbit netting with bottom 15cms netting turned out and secured. This reduces the risk of a rabbit digging under the fence.
• Rabbit/Hare – Designed specifically to keep out hares and rabbits with 1.2 metres rabbit netting supported by 2 strands of barbed wire. The bottom 15cms buried in a plough furrow where possible.
• Deer – 1.9 metre high – usually two overlapping lengths of sheep wire with plain wire along top of fence. Designed to keep out deer and other livestock.

Opportunity for owners

Farmers are well used to fencing around the farm and this experience can be put to good use practically and financially when planting a new forest. The Afforestation grant provides farmers and landowners with the opportunity to carry out forest fencing works themselves and, in agreement with their forester, to be paid for this through the grant. It can be designed to accommodate both forest and farming and is a great practical way for owners to engage at an early stage with their new forest.

Older forests at risk

Despite the size and strength of our trees as they get older they remain vulnerable to the impacts of animals. Over time weaknesses in a forest fence may allow cattle, horses, goats and deer access to the trees with potentially damaging results. Horses, goats and deer may eat the lower leaves on broadleaf trees but the most serious damage is bark stripping which may kill trees outright. The prolonged presence of cattle and horses in older forests causes poaching, closes drains and can damage roots with an increasing the risk of windblow in conifer forests. 

Maintaining fences – future proofing our forests

As our forests grow fences remain the critical line of defence against animal incursions.Fences require regular checking to assess their robustness and effectiveness as a stock-proof boundary. Posts and wire will deteriorate with time and it is essential that they are replaced and that wire is re-strained. Fallen trees may pull down a fence, badgers and foxes may break holes in a mesh fence – all these situations require timely and effective repairs. Access points such as gates, gaps and stiles should be maintained in usable condition to encourage regular visits by the owner and facilitate management.  

A robust stock-proof fence over the lifetime of the forest provides many benefits. It protects tree health, in combination with active management timber production can be optimised, financial returns are realised and the environmental integrity of the forest remains intact.

Forest owners can take on this practical responsibility themselves. The tasks are straightforward and it engages owners in an important element of forest management. Above all it is contributing to future proofing the forest in terms of growth, quality and sustainability.

Work with your forest fence and it will work for you!

Figure 2 - rabbit/hare fence

Figure 3 - goat damage 

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