Making space for natural processes: forest to bog ... · The RSPB Forsinard Flows houses a portion of the vast area of blanket bog located in Caithness and Sutherland in the north

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Making space for natural processes: forest to bog restoration at RSPB Forsinard Flows Reserve This case study demonstrates SNH’s third climate change adaptation principle: the

importance of making space for, and restoring natural processes, allowing ecosystems to

increase resilience against climate change pressures. Designated as a nature reserve in

1995, Forsinard Flows is located in Caithness and Sutherland in the north of Scotland. Here

you can find a vast area of blanket bog - Europe's largest - known as the Flow Country.

However, in the 1970s and 1980s, large areas were chosen as sites for non-native conifer

plantations, affecting the hydrological (water regulating) function of the bog, and contributing

to losses of habitats and wetland species.

Blanket bog ecosystems are at risk from climate change as they are vulnerable to changes

in rainfall and temperature. Healthy ‘active’ bogs are more resilient to climate change,

however, and adaptation focuses on restoring the natural functions of degraded bogs. The

RSPB bought the reserve in 1995, and since then, their work to fell the trees and restore the

bog hopes to improve climate change resilience by, in time, returning the bog to a healthy

state. Restoration also has the benefits of carbon storage for climate change mitigation, and

once again creating a good habitat for wetland species.

Climate change adaptation case study #2

Figure 1: The Flow Country is famous for its wide open landscapes and myriads of bog pools. (Lorne Gill/SNH)

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1. The climate change risk: blanket bogs and hydrology

Blanket bog: a unique habitat

Peat bogs are unique and spectacular landscapes. They are habitats for many rare birds and other species;

the peat preserves a detailed record of past vegetation, climates and human activity, going back thousands

of years; they capture and store atmospheric carbon in their natural state, contributing to regulating the

Earth's climate; and finally, they are also important for local communities, helping support tourism,

agriculture and field sports.

Blanket bogs rely on regular rainfall, and cool summers, conditions often found in Scotland. They consist of

two layers; the uppermost is an active living surface of peat-forming vegetation such as Sphagnum mosses

which help create permanently waterlogged conditions. Sphagnum mosses blanket the ground, and, due to

the cool, acid and waterlogged conditions, they do not fully decompose, leading to the build-up of peat soil,

which is made up of remains of mosses and other bog plants accumulated over 1000s of years. This makes

up the lower layer, which can have a depth of up to 10 metres.

Hydrology is very important to this ecosystem. If a bog’s hydrology is affected – for example, if the water

table is lowered and the surface is dried out – the Sphagnum mosses and other bog plants can no longer

survive. The surface layer begins to degrade, releasing potentially large quantities of stored carbon back into

the atmosphere, contributing to climatic warming (IUCN, 2014a).

Forested bogs

The RSPB Forsinard Flows houses a portion of the vast area of blanket bog located in Caithness and

Sutherland in the north of Scotland. Almost 5% of the world’s blanket bog is to be found here, and it is a

habitat of international importance. Much of the RSPB site is also a National Nature Reserve, (NNR).

After 1945, forestry on peatlands was promoted by the government through grants and tax concessions. In

the Flow Country, large areas were planted with non-native conifers in the 1970s and 1980s, despite having

been treeless for thousands of years, radically altering and degrading the bog and its wildlife. In order for

forests to grow on peatlands, the ground needs to be ploughed to a depth of a metre or more, and drained

dramatically affecting water table, bog vegetation, and animals. Growing trees disturb the hydrology, as the

roots extend into the peat (RSPB, 2011). Moreover, water is lost by the trees through evapotranspiration –

Figure 2: Sphagnum moss at The Flows National Nature Reserve (Lorne Gill/SNH/2020Vision)

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evaporation and transpiration – and the tree canopy intercepts rainfall, reducing the amount of water that

reaches the bog by up to 40% (IUCN, 2014b). As a result of this and deep shading, the bog vegetation is

eventually completely destroyed.

Loss of Sphagnum mosses and the generally drier conditions leads to the bog degrading, ceasing to lay

down new layers of peat, and is no longer an ‘active’ peat-forming bog. The carbon store that has

accumulated over millennia begins to be released into the atmosphere, and the bog turns from a carbon

sink, where carbon is taken out of the atmosphere, to a carbon source, where it is being released into the

atmosphere.

Facing climate change: ‘active’ bogs

Peatlands are sensitive to anticipated climate change. Temperature rise leads to the peat drying out in

summer, and an increased risk of moorland fires, while heavier rainfall may cause more erosion on those

peatlands that are already damaged or degraded (Marsden & Ebmeier, 2012).

Bogs are quite resilient habitats, having sustained climatic variations for the last 10,000 years. However,

they are only able to remain intact in the face of change if they are healthy, meaning that they are in an

active, peat-forming state (IUCN, 2014c). This is not the case when they have been exposed to land use

changes such as afforestation. The IUCN note that:

“…recent surveys have identified that more than 80% of UK peat bogs now lack

such an active living surface as a result of human impacts, and that they therefore

have little or no capacity for resilience in the face of climate change” (IUCN, 2014c).

Not only are afforested peat bogs less able to cope with climate change, but when there is no longer a living

surface layer as a result of draining and limited water supply, in their degraded state they are also releasing

carbon into the atmosphere, contributing to climatic warming.

Figure 3 (above): Map showing the Flow Country,

including The Flows National Nature Reserve

(green) and the Caithness and Sutherland

Peatlands Special Area of Conservation (blue).

Figure 4: (right) Map showing RSPB Forsinard

Flows reserve

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2. Adaptation Principle: Making space for natural processes

In order for blanket bogs to become more resilient to the negative impacts of man-made climate change it is

important to restore their natural processes to ensure that they remain peat-forming. This is a key priority.

The National Peatland Plan states that the vision for 2020 is for Scottish peatlands to be improving, and for

those in protected sites to be in good condition (SNH, 2015). The Forestry Commission has also revised its

policies since the 1980s; it is no longer permitted to establish new woodland on deep peat (over half a

metre).

Adaptation for blanket bog includes restoring the water table and hydrological functioning. Since purchasing

the reserve in the mid-1990s, the RSPB has worked to restore natural processes and bog habitats on

afforested areas at the Forsinard Flows by felling the trees, restoring the water table, controlling tree

regeneration and managing deer grazing.

In 2001, along with SNH, the Forestry Commission Scotland, and Plantlife, the RSPB was the recipient of a

£2.8 million European Union LIFE Nature grant to restore the bog. Trees have been felled over the course of

many years, and then crushed into the plough furrows, recreating the open landscape. Two phases have

been completed over the course of a decade: first trees were felled to waste, then drains were blocked, and

in the second phase brash cutting and furrow damming helped to raise the water table further.

The creation of peat dams and blocking drains raises the water table, rewetting the bog and allowing for the

growth of peat-forming vegetation. This vegetation then “smothers” the dead trees, and preserves some of

the carbon in the wood. The return of peat-forming vegetation such as Sphagnum mosses and bog cotton

restores the habitats for wetland wildlife (RSPB, 2015).

Figure 4: Pre-crushing and damming of

forestry plantation, as part of peatland

restoration at RSPB Forsinard Flows

Reserve. (G. Thompson/RSPB, February

2015).

Figure 5: Brash cutting and furrow

damming under way at RSPB Forsinard

Flows Reserve. (G. Thompson/RSPB,

February 2015)

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3. Results

This is one of the largest peatland restoration projects in the UK (RSPB, 2011).

At the sites where the earliest work was done in 1998, there has been significant recovery. The trees on this

site were less mature than those felled today, which have had an extra seventeen years to grow. There was

therefore still some bog vegetation left here, allowing for a faster recovery. Though the plough furrows and

ridges from the plantation remain, the site is returning to a healthy blanket bog state. The furrows which

contributed to exposing and oxidising the peat, are now filling up with mosses and peatland plants,

recreating the former vegetation mix found on the blanket bog, and contributing to restoring its natural

processes of capturing carbon from the atmosphere, and storing it in the peat soil (RSPB, 2011).

RSPB's Forsinard Flows Reserve has also become a centre for research on carbon, bog hydrology and

ecology in partnership with major universities and research institutes, including the Environmental Research

Institute (part of the University of the Highlands and Islands), based locally at Thurso. This research is

contributing to our understanding of how draining and disrupting the hydrology affects carbon fluxes (RSPB,

2011).

However, there is still plenty of work to be done: more trees will be felled where inappropriate forestry

remains on deep peat soils, and further drains need to be blocked (RSPB, 2011). It is the ambition that this

will lead to a vibrant ecological community, and a healthy blanket bog, which will help restore the Flow

Country. Overall, it is important to recognise that the restoration process for peatlands is slow but steady,

reflecting the pace of the peatland’s natural processes. Where funding is available, more intensive

Figure 6: Bog cotton growing at Talaheel, one of the earliest restoration areas on RSPB Forsinard Flows Reserve. (Mark

Hancock/RSPB)

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measures, like additional dams on drainage furrows, can help nature speed up the return to a healthy state.

For the work that is carried out now on more mature plantation sites, there is both the initial process of felling

and blocking drains, as well as removing timber and crushing it into the plough furrows (see Figures 4 and

5). Follow-up management involves furrow-blocking, and removing the plough ridges by machines crushing

old stumps to restore the original flat topography. This second stage helps to raise the water table more

quickly.

Research and management trials are also being carried out to improve restoration techniques. These have

responded to the challenge of carrying out restoration on these more mature sites. Here, trees can be 6-8

metres high, and also have some commercial value for biomass and timber. Increasingly, trees are being

completely removed from the site, rather than left to decompose, and more and less intensive techniques for

both tree removal and drain blocking are being trialled, in order to have the best-possible knowledge to

continue with the restoration.

Figure 7: after initial felling in 2003-2005, restoration enhancement work in 2012 involved brash crushing and blocking

furrows with peat dams (Andy Skinner/RSPB)

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4. Wider benefits

As mentioned, healthy, peat-forming blanket bogs are not only more resilient to changes in climate, but they

also contribute to mitigating climate change by storing carbon. Climate change mitigation is also a policy

driver for peatland restoration in the Scottish Government as carbon is captured and stored in peatlands,

making restoration increasingly important (Marsden & Ebmeier, 2012).

Moreover, peatland restoration contributes to re-establishing rarer wetland habitats for birds and other

species. Afforestation displaces blanket bog birds, and some species are negatively affected within about

800 metres of the forest’s edge (RSPB, 2011). These species are the replaced by woodland birds, which are

more common at a national level, than the characteristic wetland birds of the blanket bogs (Stroud et al.,

1988). However, since restoration began, species such as golden plover, dunlin and greenshank have

started to return for formerly forested areas in the Flows (RSPB, 2011).

We hope that the restoration of the bogs at Forsinard Flows will contribute to creating a vibrant natural

landscape which provides homes for several of our most important bird species, and an outstanding natural

area for visitors. 4,000 visitors come to Forsinard Flows every year, and this contributes £190,000 to the

local economy (RSPB, 2011). In addition to the estimated £10.5 million total project expenditure over 5

years, the current Flows to the Future project is expected to deliver a further £6.3 million of benefit (Gross

Value Added) across Caithness and Sutherland in the next 30 years. Healthy bogs will also become

increasingly important to ensure that more carbon is not lost into the atmosphere, helping regulate the

Earth's climate for the benefit of all, and to ensure the survival of these important habitats for future

generations.

Figure 8: Golden plover is one of the most characteristic wading birds of the Flow Country (Lorne Gill/SNH)

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For more information on the Forsinard Flows and its management please visit http://www.nnr-

scotland.org.uk/the-flows/

This publication is part of a series of case studies on the climate change adaptation principles.

For more information on the principles, and how SNH is helping nature adapt to climate change, please

contact Julia Quin [email protected],uk or Anna Brand [email protected] or visit http://

www.snh.gov.uk/climate-change/taking-action/adapting-to-change/helping-nature-adapt/

www.snh.gov.uk

www.nnr-scotland.org.uk

REFERENCES AND FURTHER READING

SNH, 2015

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