Prehistoric Wooden Walkway in Somerset Wetland Reserve Now Protected Against Climate Change
The ‘Sweet Track’, the UK’s oldest wooden walkway on Natural England’s Shapwick Heath National Nature Reserve in the Somerset Levels, is safe from the effects of climate change.
This good news comes on World Wetlands Day and shows how investing time and resources into managing wetlands can benefit our cultural heritage.
The Sweet Track was a raised wooden trackway, built by the first farming communities in 3,806 BC, designed to allow people to cross about a mile and a quarter of reed swamp, joining an island in the floodplain to a range of hills. The wood has miraculously survived for almost 6,000 years because it lies within waterlogged peat, where the lack of oxygen prevents decay. The Sweet Track is protected as a Scheduled Monument.
But climate change predictions for Somerset suggest that hot, dry summers are likely to become more common and more extreme in the future. This introduces the risk that the peat surrounding this prehistoric trackway will dry out and the archaeological remains will suffer decay and be lost.
In one area of the Shapwick Reserve, the Sweet Track is protected by an active pumping system that maintains a high water table, but towards the southern end of the reserve part of the track lies outside this system and was thought to be at risk of destruction by the peat drying out in dry summer months. A four-year project by the South West Heritage Trust, funded by Historic England, has examined the condition of the track and monitored the burial environment that surrounds it.
However, the project found that the remains of the Sweet Track outside the pumping system are not at risk of drying out, due to a combination of good water management on the rest of the reserve, plus the immediate topography. Extensive reedbed, similar to that which existed when the Sweet Track was built, maintains a high water level year-round, preventing the Sweet Track from drying out in summer.
Monitoring the site over four years allowed a thorough analysis of the burial environment under different climatic conditions, with a wet summer in 2017 followed by an especially dry one in 2018. This shows the value of longer-term monitoring of sites, especially in view of potential future climate changes when more extreme events, like the summer of 2018, are expected to become more common.
The project concluded that the full extent of the Sweet Track within the Shapwick Reserve is not currently at risk, and it will soon be removed from Historic England’s Heritage at Risk Register.
We are very proud of the work being done at Shapwick Heath National Nature Reserve to protect not just precious habitat but also history. As well as preserving the Sweet Track, peat is a great source of locking away carbon as part of a properly maintained wetland whilst creating a home to diverse wildlife unique to the Somerset Levels.
Climate changes are likely to have a significant impact on England’s cultural heritage over the coming decades. The Sweet Track on Shapwick Heath provides a marvellous example of nationally-important nature and archaeology being protected from those risks alongside each other.
As so many wetland archaeological sites have been destroyed, or are likely to be lost in coming decades, it is heartening to have this example where the incredible preservation of this special site will be maintained for future generations.