Peatland Restoration

Last Friday I attended a peatland restoration demonstration day at Lairg; hosted by Forestry Commission Scotland, and organised by Flows to the Future.

Firstly, a big thanks to you both, it was a very interesting and informative day, providing a lot of food for thought. Also thanks to The Pier for the superb lunch; if you’re in Lairg, do stop there for a meal.

Now, onto the day itself.

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The event saw representatives of various groups and organisations (SNH, RSPB Scotland, UHI ERI), along with estate managers, deer stalkers, and crofters, gather at the Forestry Commission depot at Lairg. Once there we had a short briefing from the Flows to the Future team, on peatland restoration techniques and methods; why they are happening, and what benefits the peatlands can bring, once restored. Forestry Commission Scotland, then stepped up and their staff gave a short presentation on the current works being carried out at Dalchork forest, and the various levels of policy that affect the work carried out. With context in our minds, we piled into a minibus for a tour around the Dalchork site.

The first example of a restoration technique we saw was bunding. A bund is a wall of peat, placed in a trench in the ground, to slow or stop water flow from the site, thus leading to a rise in the water table. Bunds generally measure one or two metres wide, by a metre deep, and can vary in length. In terms of slowing or stopping water flow, on this site, they seemed effective, judging by the standing pools and sphagnum areas that were developing.

My only concern was the bare peat left on the surface, though will eventually naturally recover, it could also be artificially re-vegetated.

Additionally, the consensus was that the leftover “waste” from harvesting, being left on the surface, would act as a deterrent for moorland bird species, who prefer open vistas to avoid depredation.

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Bunding

A similar method to bunding, is that of building peat dams. Peat dams are used to block drains and drainage ditches. Whereas bunding requires a trench to be dug, dams are placed directly into a drain at various intervals along its course. Their main purpose is to slow water flow, and hold areas of water and re-wet the surrounding ground.

As can be seen below, they can require maintenance if the water forces its way over, around, or through the dam. We saw another example of a dam on our tour, which was more effective, as a channel had been included to draw standing water away from the main drain onto the surrounding ground. We use this technique on the estate where I work – it seems to be far more effective than simply blocking drains at intervals.

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Peat dam (needing repairs)

Below is a demonstration of one mulching method. The brash and spare timber from the site has been used to form a dense brash mat right across the site. The theory being the benefits are two-fold: the mats run perpendicular to the drains and furrows on the site, thus holding water in those areas and keeping the water table high (as can be seen). Secondly, it provides access across the site for deer managers, who will be managing the deer population across the area, minimising grazing pressure on recovering areas.

Personally, I’m more of a fan of whole site mulching, which I will detail below. My concerns here being the deep pools, furrows and ditches, along with remaining brash and stumps, which will still provide a pain in the neck (to put it mildly) for anyone extracting carcasses from the area.

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Mulched mats

Below we can see what appears to be a snapshot of the Somme. It is in fact a freshly restored site, with work being completed only a fortnight ago.

Here, several techniques were used – mulching, stump flipping, and compressing – these are all fairly self-explanatory, I think! It will be interesting to see the site in a years time, and then as time goes by, to see how quickly it re-vegetates.

Vegetation growth could be sped up by applying heather brash, which would protect the area from erosion, and contains seeds, and has been used with success in various areas.

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Combination of restoration techniques

Next up is one of my favourite methods – mulching. It is reasonably costly, but in terms of results and ground cover, it is highly effective. This site as you can see has been newly mulched, however in my post Stalking the Scottish Savanna, you can see a sight which was mulched several years ago on the estate I work on. It may be a nightmare to stalk deer across, but we are already seeing heather and sphagnum regrowth, and a rapid rate of decomposition of timber – much faster than the comparison area which was traditionally harvested.

The mulched material can also be used to fill in drains and furrows, slowing or stopping run off, and keeping the groundwater levels stable.

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Mulching

The following three photographs are of ditch blocking techniques – but using plastic sheeting, or marine ply-board. The theory behind these methods is to impede or slow the flow of water from forestry drains, thus allowing the surrounding areas to absorb the water.

I have to admit, I am not a big fan of this method for a few reasons:

  • At the end of the day, you are still left with a deep, steep sided, drain, that rain water will be channeled into. Whilst there was some re-wetting of the ground surrounding the drain, this was more apparent in the areas that had used peat dams and drainage diversions.
  • Wooden boarding will be left to rot over the next 15-20 years, but plastics and man-made materials will be left on site, even once the site has been restored, due to the perceived cost of retrieving plastic sheeting.  My objection to this stems from a personal dislike of leaving plastic hanging around in a nominally “natural” environment.
  • Due to the force and weight of water behind the dams, they are likely to break, or the water will find a way around the dam and continue flowing downhill. (All these dams had a constant stream of water diverting around them). Resulting in costs from having to repair them, and damage to any newly established vegetation.
  • From an aesthetic perspective, I feel that using peat dams and mulched material to block drains is a far more organic process, and blends into the landscape far more readily.
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Damming Example

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A dammed drain on resources…?

This was a thought provoking day. It is always useful to see restoration work carried out by other organisations, and to chat with other land managers (irrespective of industry) to hear their thoughts on the peatlands and ongoing work. Management of such a fragile ecosystem requires thought and consideration – I’m stating the obvious, I know the same could be said for every landscape across the globe! – But it reassuring to see projects and talk to individuals who are so passionate about the landscape.

Speaking to the FCS team, there will be some establishment of woodlands in the recovery areas…but this time growing trees that would naturally occur, and only in those regions where the trees want to grow!

The right tree, in the right place. Sounds alright to me.

One Comment on “Peatland Restoration

  1. Pingback: Looking Back on 2017 – April, May & June | Wayfaring and Wandering

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