The beauty of bunds: Peatland restoration on Darwen Moor

The beauty of bunds: Peatland restoration on Darwen Moor

Darwen Moor - Credit: A.J.Critch Wildlife

Alex Hubberstey from the Lancashire Peat Partnership gives us a round up of the exciting work that’s been going on to restore one of our most iconic upland peatlands; Darwen Moor.

When you design a site for restoration, no matter how thorough you are, a small part of you is worried that you’ve missed something. That something might go wrong. That after all this time and effort, the plan you’ve made might not work. The dams you’ve put in to hold water break, or have no water behind them. Or a wildfire burns through the site damaging all the hard work you have done.

Thankfully this is not often the case. Things work. And sometimes things work even better than you could have hoped. That was the case with the recent restoration Lancashire Wildlife Trust has completed on Darwen Moor.

Historically, like most of our upland blanket bog habitats, Darwen Moor was drained to allow for ‘better’ sheep grazing conditions. Overtime, the drains got larger, some of them becoming over 10m wide and 4m deep, grazing pressure continued, and in combination with a series of wildfires, devastated the sensitive peatlands.

Nathan Thomas, holding some sphagnum moss, leading a guided walk on Darwen Moor.

Nathan Thomas leading a guided walk on Darwen Moor. Credit: A.J.Critch Wildlife

That’s where we come in

We designed a restoration plan, secured funding, got the contractors in place, kept everything running smoothly, and most importantly, got a section of Darwen Moor re-wetted. The all-important question, did it work? Yes!

Around 80 hectares of Darwen Moor is now holding water once again, reducing flooding downstream, keeping sediment out of our watercourses, reducing the risk of wildfires, and helping threatened species recover.

Over 1,000 ditch blocks, 5km of bunding and 25,000 sphagnum moss plugs were installed. All designed to help the habitat begin its long process towards restoration. Peatland restoration is not a quick thing, our work this past season will likely take five years for us to start noticing some changes in the vegetation, and likely over 50 years before it functions as a near-natural blanket bog again.

Over 1,000 ditch blocks, 5km of bunding and 25,000 sphagnum plugs were installed.

Sphagnum moss planting on Darwen Moor

Sphagnum moss planting on Darwen Moor - Credit: Annabelle Brittle

What are bunds?

Bunds are lines of compressed peat which sit both above and below ground to form a waterproof barrier. In the lowland peatlands, deep trench bunding is a significant part of restoration, but in the uplands, it is more about installing ditch blocks and we use bunding where purple moor grass (Molinia caerulea) is dominant.

Although this plant is a part of a natural blanket bog habitat, when a peatland is damaged and draining water, purple moor grass can become dominant and then poses a significant wildfire risk. Unlike most plants that drop their dead leaves, purple moor grass keeps the dead leaves attached to its main stem. This creates a bed of dry straw which during the summer becomes dry as a bone and a simple spark can ignite a vast area.

In their current state, the West Pennines are dominated by purple moor grass.

Darwen moor wildfire

Darwen Moor wildfire - Credit: Alan Wright

What is the solution?

The solution (or at least one of them) is to install bunding to stop water draining off the bog and restore the naturally high water table. Purple moor grass doesn’t like getting its feet too wet, and in the pools formed behind the bunds it gets outcompeted by cotton grasses and sphagnum mosses helping to reduce its dominance.

When first installed, bunding can make the land look drastically different. Where once it was flat, now it is bumpy and covered in small pools of water. Give it time. In a few years these bunds will disappear among the vegetation and the pools will become a carpet of sphagnum moss.

Scallop bunding on Darwen Moor & contractors installing bunding

Scallop bunding on Darwen Moor (left) | Contractors installing bunding (right) - Credit: Alex Hubberstey

Screenshot of the main bunding zone on Darwen Moor taken from Google Earth

Screenshot of the main bunding zone on Darwen Moor taken from Google Earth

Most importantly, we are seeing a change in the hydrology of the land already. Using GIS (the technical term for mapping on a computer) we’ve seen a noticeable change when you compare before and after the bunds were installed from satellite imagery. The land is wet again. Looking on Google Earth you can see the network of bunds that we have created, but from the ground you don’t realise the full extent of them.

We know it is working, and the computers and satellites tell us the same, but what does the wildlife think?

What does the wildlife think?

Since the bunding has been installed, we’ve seen red grouse (Lagopus lagopus scotia) displaying on the tops of the bunds. Curlew (Numenius arquata) foraging in the pools for invertebrates. We have even seen a flock of golden plover (Pluvialis apricaria), over 30 individuals strong, utilising the new open water habitats that have been created. Most likely this flock was en route to its breeding grounds in Scandanavia, but there is a possibility some of these decided to stay and nest on Darwen Moor instead. As the habitat slowly restores, numbers of these bird species will also increase.

Our peatlands are incredibly special places. By restoring them we are not only restoring the habitat for a myriad of often rare and threatened species, we are also helping to naturally mitigate flooding and reducing the carbon emissions that degraded peatlands produce. The moral of the story. Let’s love our peatlands.

 

Learn more about the Lancashire Peat Partnership