Pessimistic predictions of the effects of the Hymenoscyphus fraxineus ‘ash dieback’ fungus on English ash woodlands talk of an ‘ash armageddon’ with most of Britain’s 100 million plus ash trees dead or dying within a few years.
“Catastrophic events happen in nature,” said Luke Barley, National Trust ranger for the White Peak. “We could just leave it. But then our grandchildren won’t see a Dovedale that looks anything like we see it.”
The steep wooded valleys of Dovedale, Lathkill Dale, Monsal Dale and Monks Dale in the White Peak have drawn millions of tourists over the years, along with four centuries of poets, painters and writers depicting a landscape dominated by ash trees.
As the ash woodlands of Dovedale turned from pale green to yellow this autumn, Luke and his colleagues have reported signs of ash dieback all over the White Peak, unsurprisingly, he notes, because the spores that cause the disease are carried by the wind.
“We felt it was inevitable, because the White Peak is an ash landscape. Now we need to manage it and mitigate for it.”
The disease originated in the Far east, where native ash species have co-evolved with the fungus and can survive its attacks, whereas European ash trees seem to have little defence. The spread of ash dieback throughout Europe since its first outbreak in 1992 was exacerbated by the movement of infected trees for commercial reasons - to grow on in a country of cheaper labour, for example.
Agencies like the National Trust, Natural England, The Forestry Commission and the Peak District National Park Authority are working together to monitor the spread of the disease in the limestone valleys of the White Peak where ash trees, an “iconic British species’’ says Luke, have been harvested for generations of tool handles, hockey sticks and longbows.
“Some places in Europe have seen more than 90% of the ash trees infected, and if that happened in our ash-dominated woodlands, they could stop functioning as woodland ecosystems with all that implies for other woodland species,” said Luke Barley.
Ash is a ‘pioneer’ species, whose seedlings “grow like cress in cleared and open ground”, Luke said. The predominance of ash in the White Peak’s woodlands is thus a result of many hundreds of years of woodland clearances for farming, quarrying and mining.
Joe Alsop from Natural England points to secluded ravine woodlands that evaded human interference, like Matlock Wood in Matlock Bath, which include wych elm, yew and lime as well as ash.
“We’d like to restore some species we would have had a lot more of historically, and hopefully that will be a good thing for biodiversity,” he said. “Matlock Wood gives us a snapshot of where we could be, and maybe shows how many ravine woodlands would have looked in the past.”
As well as a monitoring programme in 100 small patches of the Peak District to check the progress of ash and other species, conservationists will be actively cutting down some trees to give space to older ash which could be more tolerant.
The woodland management work could also allow other native trees to gain a foothold, while Luke and colleagues seek funding to plant species that would have grown in the ravines before human intervention, like hazel, rock whitebeam, lime and wych elm.
Work is ongoing nationally on the spread of ash dieback, and there are some encouraging signs that Britain’s ash trees may be more tolerant than European variants, and maybe an ‘ash armageddon’ can be averted here.
But conservationists are also watching the spread of a small Asian beetle across Europe. The emerald ash borer beetle (whose larvae burrow into ash trees and kill them) arrived a few years ago in Moscow, probably on a shipping pallet that evaded an official disinfection in transit.
So the White Peak’s ash-dominated ravine woodlands will soon face another challenge. It seems the nature of the steep valleys of the White Peak have to change, or could stop being woodlands altogether.
“It is a call to action,” said Luke. “We can’t stop ash dieback, all we can do is try and manage these woodlands so what’s important about them continues.”
More info: https://www.nationaltrust.org.uk/whitepeak