Serious storm damage to forests may not be bad as originally feared

Two weeks after Storm Darwin, the extent of windblow in Irish forests is becoming clearer, but a full inventory of damage won’t be completed for a number of weeks.

The storm swept in from the Atlantic hitting Clare, west Limerick and north Kerry first and then on to Cork before sweeping across Waterford, Wexford, Kilkenny, Carlow and parts of the midlands. The forests damaged on the night of February 12-13 follow this pathway with some areas reporting severe damage, especially within a 50km circumference of Mullaghareirk Mountain.

However, early estimates of windblow of up to 8,000ha in Coillte forests alone have been revised downwards. Damage is estimated be closer to 5,000 ha but reports are still coming in of extensive damage to private forests.

Tom Hayes, Minister of State with responsibility for forestry, appealed for a calm approach in dealing with the problem of selling and clearing timber in windblown forests. He reminded plantation owners that “timber that has fallen can last up to a year in the forest without degrading and will retain timber value”. The Minister is currently chairing a taskforce representing forest owners and the industry.

Storm aftermath

Windblow affects forest owner financially and psychologically. A plantation of blown and shattered trees is a despairing sight because a forest, unlike any other crop, takes decades to establish and again to replace.

Daragh Little, managing director of FEL, summed up the feelings of many with damaged plantations: “My own forest was destroyed by the storm so I understand the pain and financial loss forest owners are going through. However, all is not lost as the blown timber has substantial value and can be recovered. I intend to get back up and running as quickly as possible as demand for timber is high and prices are good.” He also looked at the positives. “I will replant with improved planting stock that will give me better quality timber sooner.”

Short-term action

If first estimates of one million cubic metres of damage are correct, this represents 30% of the annual harvest and could be dealt with relatively quickly providing the following steps are taken:

While timber should command good prices, there are likely to be financial and psychological implications for many. In this respect the following would be helpful:

Chainsaw operators will be needed in some sites to assist harvesting operators. Chainsaw work is dangerous in normal felling but is extremely dangerous in windblown sites. Only properly trained and equipped operators should be employed.

Long-term

Once the current windblow has been cleared, the taskforce might continue its work in association with COFORD and Teagasc and examine the long-term implications of storm damage and ways of minimising windblow. A good deal of information already exists but there is need to update current information and silvicultural practices, especially in relation to thinning high yielding coniferous plantations.

Many crops greater than yield class (YC) 24 (m3/ha/annum) are more vulnerable to windblow much earlier than slow growing plantations. For example, Sitka spruce crops planted in wet mineral soils can reach 14m top heights and over between 14 and 16 years of age. In high-risk exposed sites, 15m is regarded as the maximum attainable height (MAH) while a plantation may reach 24m MAH in moderate risk sites.

This also raises the question of whether to adopt a thin or no thin regime. “Where the decision to thin is taken, the storm highlighted the importance of thinning early and organising the layout of forest roads and turning areas in order to avoid opening the forest to the prevailing wind,” said John Roche of the Forestry Company.

Foresters and owners have been too conservative in the timing of first thinnings. High-yielding crops between YC 24 and 30 may need to be thinned between 12 and 14 years and every three years thereafter. These crops will reach a top height of 20m as early as year 25, which is regarded as the ‘critical height’ for all but the most sheltered sites in Ireland.

Forests will always be at risk from windblow once they reach the productive stage. When a storm as strong as Darwin occurs, with gusts of up to 177km per hour recorded, some damage is inevitable. It should be remembered that the standing volume in Irish forests is almost 100 million cubic metres, so every 1.0 million m3 represents 1% of the total forest estate and 25% of the annual increment which averaged 4.3 million m3 between 2006 and 2012 according to The Second National Forests Inventory published by the Forest Service last year.

While it is likely that volume will exceed a million cubic metres, this can be removed in a few months with good planning between forestry companies, plantation owners and timber processors. The demand should remain strong, especially at a time when some mills have been on short time in recent months because of a shortage of supply.

Storm damage

Foresters and plantation owners have been inspecting forests around the country since Thursday February 14. Unlike bad storms in the past, this is the first time large-scale damage has been caused to private plantations so the inventory of windblown forests is taking longer because the size of the forest estate has increased in recent years. For example, when the devastating storm of 1974 took place, Ireland had 340,000ha of forests compared with 765,000ha today.

Nicholas Cotter, Mid Western Forestry, like other foresters has been surveying forests he has established over the years. “It’s bad in west Limerick, especially in areas that have been thinned, but even 10- to 15-year-old unthinned plantations have been damaged.”

Padraig Egan of SWS Forestry reported severe damage in thinned forests but agreed that unthinned plantations did not escape. “Whether forests are exposed or not, wet or dry, first or second thinned, it made no difference,” he said. “The main counties where we have problems are Limerick, Clare, Kerry, Cork, Tipperary and Galway, with damage varying from complete levelling of crops in West Clare and West Cork to row after row of trees in Tipperary.”

Daragh Little of Forest Enterprises Ltd (FEL) said extensive and severe damage has been caused to plantations in Limerick and Kerry. He said many are completely flattened. “In general the plantations affected are thinned and those also over 13m top height regardless of thinning status,” he claimed.

John Roche of the Forestry Company reported “some windblow, particularly in sites that were first thinned since last summer”.