PLANS are being drawn up to plant 250,000 trees on the slopes above the A83 to prevent landslips that have closed the road eight times in the past five years.
According to experts, the roots of the trees would bind the soil and also help heavy rainfall soak down into the ground rather than running off towards the road, taking part of the hillside with it.
Since 2009 the Scottish Government has invested £4.9 million to combat the problems on the road, which runs between the head of Loch Long and that of Loch Fyne.
This includes the construction of a local diversion route at the Rest and Be Thankful.
But twice since it opened, the A83 has been closed by landslips further north, and the diversion was unable to be used. Motorists were again left with the options of a 50-mile detour using the A82 to Crianlarich and Tyndrum, or travelling by way of the Gourock to Dunoon ferry.
Transport Scotland is still seeking a long-term solution and is working with Forestry Commission Scotland (FCS) and local landowners to develop a strategy.
A spokeswoman said: "Tree planting to help stabilise the slope above the A83 is one of many options being looked at. We have established this would have to be done in conjunction with other measures and are discussing this with our stakeholders."
Syd House, FCS's regional manager for Perth and Argyll has been working on a plan. He said there was plenty evidence from the likes of the Philippines, Brazil and California that showed when there is deforestation and the vegetation is removed, intense rainfall would wash considerable amounts of soil away in landslides.
Mr House added: "In addition, the Alpine countries have long recognised the importance of protection forestry. That is woodland established to protect villages and communities from land slippages and avalanches. They manage the forests simply to protect the asset. It is exactly that principle we are talking about for the A83."
He said many different things could be done for the road.
"Hard engineering, netting, clearing rock faces are being looked at by Transport Scotland. However, tree planting would contribute to the long-term solution. We are talking about something that will help stabilise the slopes over the next 20,30, 50 years, indeed in perpetuity," he said.
"It wouldn't be commercial conifer forestry because that would involve taking the trees off at some point. Nor would it involve heavy ploughing or drainage.
"We are talking light touch. We are talking about native species and those that are particularly good at binding such as hazel, willow, hawthorn, aspen alder, birch, maybe oak. The deeper the roots, the more they can bind the soil," he said.
But, he said, if the soil was shallow and the water got between it and the rockface, it would not matter whether trees were planted or not as the ground would still slip.
However, tests of the land at the A83 suggest there is enough soil
He added: "The initial project would be about 247 acres, planting about 2500 per hectare, so about 250,000 trees."
He said there was also another theory for the landslips. With land grazed by livestock such as sheep over centuries there was a compaction of the soil. The top 6in could be wet, then after that it is quite dry.
This led to the water coming off the surface more rapidly, rather than soaking downwards, thereby contributing to landslips. "But trees would help the ground act like a sponge," said Mr House.
If the tree planting proved successful on the A83, then a similar project could be tried on other landslip prone areas in the West Highlands, the Great Glen and Glen Ogle above Lochearnhead, he said.
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules hereComments are closed on this article