2019 was a year of weather extremes in the UK, with record-breaking warm temperatures in both summer and winter – a salutary reminder, if we needed it, of the reality of climate change. In this blog, Senior Conservation Scientist Mark Hancock, talks about the amazing peatland work our scientists are up to in the Flow Country.
There has never been more need for action, and one of the simplest actions we can take to reduce climate change is to restore our moors and bogs – our peatlands. RSPB has been working for decades to conserve and restore peatlands for their remarkable wildlife - like greenshanks and golden plovers - and their distinctive plants, like Sphagnum mosses and insect-eating sundews. Climate change now provides an even stronger imperative. Consequently, our peatlands work has scaled up massively in recent years, both in terms of restoration management, and the science that informs it.
Over 1000s of years, peatland plants have captured carbon from the atmosphere. Much of this carbon remains locked up in the waterlogged peat as ancient plant remains. In damaged peatlands, water drains from the peat, which then degrades, releasing carbon dioxide, and accelerating climate change. Restoring waterlogged conditions allows bog plants to thrive, protecting the peat and restoring carbon capture from the atmosphere. At the same time, these watery conditions are perfect for the wetland birds that are so emblematic of bogs.
The UK’s largest peatland is the Flow Country of northern Scotland, a 4000 km2 blanket bog - the biggest in Europe. Here you will find RSPB’s largest nature reserve, at Forsinard. This is a vast open landscape of lochs, pools and bogs, dotted with mountains and low hills, under a huge and ever-changing sky. At the start of the short summer season, song-flighting greenshanks criss-cross above, while on the lochs, scoters complete their courtship rituals with soft piping calls. Later in the summer, dark-winged young hen harriers practice their hunting, and black-throated divers with young defend their lochs ferociously against intruding birds.
Bog cotton, dark-water pools, low hills and dramatic clouds – classic Flow Country scenery at Forsinard RSPB reserve
Sadly, large areas of the Flow Country were damaged in the 1980s by the establishment of inappropriate forestry plantations. This type of deep-peat afforestation would never be permitted nowadays, not just because quality bogs are now protected by law, but also because it would be seen as poor forestry practice. A major part of our work at Forsinard is restoring some of these areas back to bog. Trees are felled and removed (if they have grown well) or mulched (if they have not). Deep forestry drains are blocked with dams of peat. Gradually these areas recover, water tables rise, bog plants colonise, and in due course, bog wildlife arrives.
This novel “forest to bog” restoration work requires us to develop new management approaches, and discover new scientific knowledge. This is where we can use of one of RSPB’s great strengths – our joint working between land managers and scientists. This helps us establish ambitious, large-scale management trials. At Forsinard, we are testing various approaches to restoration of ex-forestry plantations. Techniques range from ‘cheap & cheerful’ to ‘top of the range’. An important question we will answer is, what exactly do we gain by spending more money per hectare on restoration? Are cheaper approaches ‘good enough’, allowing us to restore a larger area overall?
Paul Stagg of RSPB’s Conservation Science department measures water table in bog habitat at Forsinard, as a comparison for restoration sites within the forestry area behind. Restoring a high and stable water table, similar to that of a bog, is the first stage of the restoration process.
Restoring peatlands is a slow process but we are now getting clear scientific evidence that bog conditions are re-establishing in our earliest forest-to-bog restoration areas, in terms both of vegetation and water quality. Moisture-loving plants are well established after 15 years, and as bog plants re-assert themselves, we expect them to re-create the low nutrient, acid conditions, that define bog habitat and attract bog wildlife.
Meanwhile, the management trials we have set up on our reserve present great opportunities for climate scientists from our academic partners. The depth of science work going on around peatland restoration in the Flow Country recently featured in a special issue of the journal Mires and Peat. Using cutting edge technologies like eddy-covariance flux towers, our research partnerships are measuring how quickly the restoration areas resume their uptake of carbon from the atmosphere. In some cases, estimates suggest that this is more or less fully restored after only 5-10 years. During the restoration process, the pattern of carbon dioxide exchange between peat soils and the atmosphere diverges from that of forestry plantations, and starts to resemble that of intact bogs. These changes in soil and vegetation can then result in older restoration areas becoming net sinks of carbon, effectively starting to help cool the climate, just as intact peatlands do.
Rebecca McKenzie of one of our academic partners, the Environmental Research Institute (part of the University of the Highlands and Islands) checks the operation of an eddy-covariance flux tower, in a restoration area at Forsinard RSPB reserve. Is the “climate cooling” function of the bog already re-established in this restoration area?
The Flow Country is currently under consideration as a World Heritage Site: the ultimate accolade, that if successful, will recognise its ‘outstanding universal value’. Meanwhile, government support for peatland restoration has never been higher. RSPB’s pioneering restoration work at Forsinard, supported by a strong scientific research community, looks ever more likely to sit within a larger landscape whose full true value – for climate and wildlife – is both appreciated and protected.
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