Sunday, August 11, 2013

ASH TREES: Chalara Ash Dieback

Tragically, these wonderful, graceful native trees are severely threatened in the UK, where our landscape- which includes 92 million Ash trees- could be changed as it was by the onslaught of Dutch Elm disease in the late 60's.  This time, it is by a deadly fungus- Chalara fraxinea- which especially affects the Common Ash,  Fraxinea excelsior (so named for its height- rising to the Heavens, sometimes to 40m!).

The disease has spread from Northern Europe- where 90% of Ashes in Denmark have been infected-  first reaching the UK in February 2012, and now being found in 17 Counties.

Before going into more details, I would like to celebrate the Ash trees as they now are, starting with photos of skeletal Winter ones in the London region:

 I love the fluid curves at the extremities of the branches, described by Gerald Manly Hopkins as "contradictory supple curvings" (he also makes a comparison between a Bluebell and an Ash:"Its inscape is mixed of strength and grace, like an ash-tree.")   

Purple Ash flower clusters appear before the leaves...

Photo by Donar Reiskoffer
 I find the animal hoof-like black buds strangely magical...

And the compound leaves make endless wonderful patterns

The patterns are enriched by the large bunches of winged seed Keys

As a child, I believed these "keys" were really functional keys for locks, which added to their magic!

Younger trees have smooth bark...

Here are some older ones:

And here you can see the diamond shape formation of the mature tree's bark

 Ash trees are very much part of Folklore- they are embedded in our consciousness.  The very words "The Ash Grove" conjure up a romantic image, based on remembrances of the old Welsh lyrics to the song, of which there are many versions.  Here is a link to one by Benjamin Britten and Peter Pears.

Ashes have long been credited with both magic and healing powers in many countries.  To heal them in Britain, sick children would be passed through the cleft of a tree- and subsequently their health would be related to that of this particular tree.

The Ash is also vital in Viking mythology.  The World Tree, Yggdrasil, was depicted as an Ash.  This tree formed the world's scaffold or Cosmic Axis.  Growing on an island in the ocean, the World Serpent lay in its roots which reached down to the underworld while its trunk reached up to the Heavens and its branches spread over the Earth.  An Eagle sat in the canopy and a squirrel conveyed messages between him and the Serpent, while deer fed on the leaves and the World's rivers poured from their antlers and a Goat dispensed mead (a honey-like substance can in fact be obtained from ash bark and leaves) to the god Odin's Great Hall and the gods gathered under this guardian tree.  

Below is an illustration of this concept, by Friedrich Wilhelm Heine:

"The Ash Yggdrasil" (1886)
We are all familiar with rhymes associated with Ash trees- such as "The Ash before the Oak and we shall have a soak- The Oak before the Ash and we shall have a splash".  One I did not know of is: "Beware the ash, it courts a flash, beware the Oak, it courts a stroke".   Now this last one is interesting as it refers to the fact that these two trees attract lightening more than any others.   Lightening was seen by the ancients as a fertilizing power from the heavens down to earth.  The word "ash" derives from the Icelandic aske, which means "a great fire blaze" while the botanical name for the Ash, Fraxinus, means "Great Fire Light".  Consequently, the Ash is often thought of as the Father of mankind and in Scandinavian myths the first man Askr was made from Ash, and they called themselves Aeslings, men of Ash.

There are countless other magical myths associated with the tree- from Druids wands to Witches broomsticks.  You can read about some of them on the Trees for Life site.

Apart from all this Ash timber has very practical properties.  Having a tight grain and being very flexible, it has great strength and load-bearing uses which has long made it indispensable.   In the past it was used for chariots and weapons, while ash has been traditionally the choice for the handles of tools.  Also in woodlands- Ashes  having light foliage which does not block out sunlight-  wild flowers and other plants are able to flourish beneath them.

 I have written about all this at some length to emphasize what a loss it would be to us in so very many ways if this invaluable, historical and miraculous tree was lost from our landscape- let alone for the fact that we can ill-afford to lose our 92 million Ash tree canopy.  

So, to return to this horrible fungus, Chalara fraxinia, what is being done to halt its progress?

As the main spread of the disease seemed to be through the importing of infected saplings to nurseries in Britain, it was finally decided to ban this trade- but not until far to late.  The first cases in this country were noted in February 2012- from a Dutch consignment, when the Netherlands already had confirmed cases in 2010- but the law was not enforced until October 2012.

The Government has set up a Chalara Management Plan, the four key objectives being:
  • Reducing the rate of spread of the disease
  • Developing resistance to the disease in the native ash tree population
  • Encouraging  landowner, citizen and industry engagement in surveillance, monitoring and action in tackling the problem
  • Building economic and environmental resilience in woodlands and in associated industries
 Scientists have unravelled the genetic code of the fungus, hoping in the long term to stop the epidemic- see BBC link

The Forestry Commission have set up a site, which includes showing how citizens can help by reporting cases.  Below, are five examples of what to look out for:

The above diamond shape is significant

 The Forestry Commission regularly updates this information and map showing the Distribution and progress of Chalara :

  Confirmed findings at 12 August 2013:

Nursery sites - 24
Recently planted sites - 336
Wider environment, e.g. established woodland - 194
Total: 554

Outbreak map.

 Well, the immediate prospects of our beloved Ash trees do not look optimistic.  We can only hope that scientists are successful in finding a breakthrough or that Nature comes to our rescue.  Let's just hope that future children don't grow up knowing the graceful Ash tree only through Mythology.