Will it really be Ashes to Ashes?
The alarmingly rapid spread of a fungus deadly to our native Common Ash tree has been making headlines for a few weeks now. This deadly fungus has ripped through Denmark’s Ash population and threatens to do the same to ours… Just like Dutch Elm Disease did some 30 or 40 years ago.
From a perspective it seems like lessons haven’t been learned from the Dutch Elm Disease epidemic that saw the native English Elm all but wiped out and effectively erased from the landscape. The common Ash is a very common large tree in England and is a master at colonizing spare ground.
Trees all of kinds often have parasites and infections. In fact some individual trees live their entire life with a fungal infection. Oak trees are an example of this and there are several fungi that can infect an English Oak to my knowledge. A fungus or bacterium does not want to kill its host (at least not quickly) because it will lose its habitat and food source. Ash Dieback Disease is not a native fungus though and as such there is no symbiotic relationship with the native Ash and the common Ash has no resistance to it.
This is the same thing that happened with Dutch Elm Disease: English Elm has always suffered from infections by a species of fungus but this wasn’t a problem because the two species evolved together. A strain of the fungus (native to the Far East and which Far Eastern Elms were resistant to), came to England on infected timber with a beetle that also preyed on the Elm. The combination of the foreign strain of fungus and the beetle simply wiped out the English Elm (almost completely).
The government seems to have been too late (so far it would seem), in introducing a ban on imports of foreign Ash timber. Control of imported timber into the UK is not what it could be. Indeed the whole forestry system has been neglected in the UK for so long that we cannot produce quality home-grown timber in any sort of quantity to speak of any more. Countries like Sweden have got it right: Nearly all woodland there is privately owned and managed and colossal quantities of high quality timber are exported.
Relying on foreign imports of timber and the potential problems it can cause is far from being the way that I would like to see Forestry in the UK.
The BBC have been covering the Ash Dieback Disease epidemic very well indeed as have The Woodland Trust. The links below from the BBC are very useful for further reading:
At the time of writing, the image below shows the infection in Britain:
The BBC have also written up an interesting piece on the ecology of the common Ash, which I have re-printed below:
Known as the common or European ash, the tree – the UK’s only native ash species – is scientifically known as Fraxinus excelsior.
It is the UK’s third most abundant species of broadleaf tree (after oak and birch), covering 129,000 hectares of woodland.
Ash is deemed to be a very important species within the UK’s hedgerows and accounts for about for about 10% of the nation’s estimated 123 million “non-woodland” trees.
The common ash is a large deciduous tree that can reach heights in excess of 40 metres (130ft). It can live up to 400 years but coppiced trees can live for centuries longer. The species is wind pollinated, and the seeds (known as keys) are primarily dispersed by the wind.
As the species is long-lived, it is important for wildlife. It supports specialist deadwood species, such as the lesser stag beetle and hole nesting birds, including owls and woodpeckers.
Ash woodlands have light, open canopies, so are an important habitat for flora such as bluebells and ramsons. Birds like bullfinches feed on the trees’ seeds.
Also, ash provides an important habitat for more than a quarter of Britain’s lichen, including nearly 14% of the nationally rare and nationally scarce species.
Upland mixed ash woodlands are listed as a priority habitat under the UK Biodiversity Action Plan.