Ash dieback disease

Posted: Wednesday 28 November 2012
by Kate Bradbury

Walking through the park, I spotted two ash trees with withered leaves. Were they infected with ash dieback or were they just brown because it was autumn?

Ash tree foliage

Walking through the park last week, I spotted two young ash trees that I’d previously paid no attention to. The leaves were withered and fading; I wondered if they were infected with ash dieback fungus, Chalara fraxinea, or if they were just brown because it was autumn. I looked in vain for lens-shaped markings on the bark - another sign of the disease - and searched online back at home to see if dieback had been confirmed in my area. It hadn’t, but I emailed a photograph of the leaves to the Forestry Commission anyway.

Until a few weeks ago, ash trees had the same status in gardens as dandelions (or so it seemed to me). A friend has several ash stumps still growing in her borders. They refuse to die, constantly sending up shoots, determined to regrow. She cuts them back and also digs up and destroys ash saplings in her lawn, muttering at the perceived invasion of her garden.

As we all now know, ash dieback has infected 90 per cent of Denmark’s ash trees and has the potential to devastate the British landscape. It is likely that the spores were carried on the wind from the Continent, but they have also entered the country via imported ash saplings. Given that ash is such a prolific self-seeder, I’m not sure why we needed to import ash in the first place, but the practice has now been banned and perhaps this outbreak will encourage us to check the provenance of native plants before we buy them.

The disease mainly affects young plants, but eventually takes hold of older trees, meaning we could lose some of our most ancient specimens. Experts have suggested that while dieback will take several years to kill off the ash, our woodlands will never look the same again.

Yet scientists are now saying that attempts to control the disease (such as burning infected trees and leaves, or even using fungicide) are futile. On the Guardian website, plant biologist Professor James Brown says: “Evidence from Lithuania, Denmark and Sweden indicates that there is genetic variation in the resistance of ash trees to dieback … perhaps the long-term outlook is not so bleak.”

Even if just one per cent of our ash trees is resistant to the disease, the population could regenerate itself in time. And perhaps the seedlings of infected trees will develop resistance. I’m no plant biologist, but I know plants evolve - they have to.

I have new respect for the stumps that refuse to die in my friend’s garden. They’re suddenly symbolic of a tremendous fight to resist sickness and protect our heritage. Will the ash tree be beaten? I hope not.

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Jobod 09/01/2013 at 02:09

This picture looks like elder not ash...

nutcutlet 09/01/2013 at 07:33

Does rather. and not dying back either. The yellow ones aren't elder or ash. Field maple or something. 

Saw an article on bees once, illustrated with a pic of a wasp on it's nest.

Are we too picky?