Ash tree set for extinction in Europe

By Claire Marshall

BBC Environment Correspondent

23 March 2016 

The ash tree is likely to be wiped out in Europe, according to a review of the evidence.

The trees are being killed off by the fungal disease ash-dieback along with an invasive beetle called the emerald ash borer.

According to the research, published in the Journal of Ecology, the British countryside will never look the same again.

The paper says that the ash will most likely be "eliminated" in Europe.

This could mirror the way Dutch elm disease largely wiped out the elm in the 1980s.

Ash trees are a key part of the treescape of Britain. You don't have to go to the countryside to see them. In and around towns and cities there are 2.2 million. In woodland, only the oak is more common.

However, according to a review led by Dr Peter Thomas of Keele University and published in the Journal of Ecology, "between the fungal disease ash dieback and a bright green beetle called the emerald ash borer, it is likely that almost all ash trees in Europe will be wiped out - just as the elm was largely eliminated by Dutch elm disease".

Ash dieback, also known as Chalara, is a disease that was first seen in Eastern Europe in 1992. It now affects more than 2 million sq km, from Scandinavia to Italy.

It was identified in England in 2012 in a consignment of imported infected trees. It has since spread from Norfolk and Suffolk to South Wales. Caused by the fungus Hymenoscyphus fraxineus, it kills the leaves, then the branches, trunk and eventually the whole tree. It has the potential to destroy 95% of ash trees in the UK.

The emerald ash borer is a bright green beetle that, like ash dieback, is native to Asia. It's not yet in the UK but is spreading west from Moscow at a rate of 25 miles (41 km) a year and is thought to have reached Sweden.

The adult beetles feed on ash trees and cause little damage. However the larvae bore under the bark and in to the wood, killing the tree.

According to Dr Thomas: "Our European ash is very susceptible to the beetle. It is only a matter of time before it spreads across the rest of Europe - including Britain - and the beetle is set to become the biggest threat faced by ash in Europe, potentially far more serious than ash dieback."

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Trees under threat: The oak, beech and birch could be lost if Britain does not act quickly

They help define our landscape, but it could be radically altered over the next century unless steps are taken to stop the onslaught of pests

IAN JOHNSTON

Sunday 11 January 2015

Urgent action must be taken to save Britain's forests from being devastated by a wave of new diseases brought by climate change and the global trade in plants, leading scientists have warned.

Species such as oak, ash, Scots pine, larch, beech, birch and juniper are all at risk from a host of new bugs, fungi and bacteria, some of which are already in the country. Others are expected to arrive soon.

One expert has warned that Britain's forests could suffer a similar fate to woodlands in much of the US, where vast stands of trees have been wiped out by beetles, whose numbers have exploded in the warmer temperatures. 

In a special issue of the journal Forestry, published this month, researchers have laid out a number of techniques that could help build resistance to pests and diseases.

These include creating genetically modified trees designed to withstand conditions such as ash die-back, and persuading the forestry industry to plant more "natural" forests that are better able than regimented, single-species plantations to withstand such onslaughts.

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