Cnut Up A Tree


No, it's not a deliberately coy misspelling in the title. Shame on you for thinking that.


We are going to be talking about an ancient English king from Denmark and his relevance to today's troubled society. You may know him better as Canute, which is a phonetic spelling of his name. And yes, it is the one that is famous for commanding the tide to stay out and getting wet feet for his pains.


One the major news stories at the moment is the recent appearance of ash die-back disease, which seems to be spreading rapidly through the forests of Britain. First noticed in Poland in 1992, it was detected in England in February this year, although it was not accurately identified until some time around July.

The problem is a fungus chalara fraxinea, which is spread though physical contact with diseased wood and also by spores borne on the wind. It has devastated large areas of woodland on the European mainland and it is estimated that up to 90% of Denmark's ash trees have succumbed.

No preventative treatment is known and once infected a tree cannot be cured. There is no suggestion that the fungus is anything other than completely natural, a spontaneous mutation of an existing strain. These mutations happen all of the time - it is the basis of evolution - and sometimes they have unfortunate (to our eyes) but entirely natural effects.

The most common action taken to prevent the spread of the fungus has been to clear fell nearby woodlands to create the equivalent of a fire break. This has had limited success for two reasons: firstly, the spores can be wind carried, so they simply fly over the break; and secondly the clear felling destroys healthy and resistant trees that are not infected.

And these reasons are the main point of this post.

First, some background thoughts. I had never thought of ash trees as being any kind of commercially valuable resource. It turns out they are quite versatile and provide a good general-purpose easy-working wood. It is used for quite a few purposes from longbows to car chassis. More comon uses now include tool handles, snooker cues and firewood.

A couple of our gardens have been in the shadow of ash trees and we were always pulling up seedlings that had spontaneously taken root. They were a very vigorous weed and I can't imagine anyone wanting to buy the things. Apparently some people do because the the indigenous UK growing industry seems unable to keep up with demand and we have to import from the mainland. And these imports, like nearly all other imports from other EU countries, arrive on our island without let or hindrance because of of our membership of the Single Market.

Last Friday I listened on Radio 4 to a government minister (it may have been Owen Paterson) explaining that ash die-back is a very serious problem and that all imports of ash trees would be banned from the following Monday. And like many people must have done I thought to myself: why the following Monday? If it's that bad a problem, why not immediately? Why not now?

Or alternatively, why bother? We know that the fungus is already here. We know that it is spread on the wind. We can't stop it, we can't cure it. It has probably blown in from the mainland at least once already and it may have been here for quite some time. Even if our (very expensive) efforts were to eradicate the fungus, it would be back again in the future. Is the effort really worthwhile?

Remember that not every tree would succumb to the fungus, some 10% to 40% seem to be resistant. Although the sudden disappearance of most of an entire species of tree from the landscape may be dramatic in the short term, they would be replenished by more robust specimens in the fullness of time.

And we've been round this way not that long ago - remember Dutch Elm Disease? That was big in the 1970's. Well the trees died and others were planted in their place and are starting to fill in the gaps. The life span of a tree is quite long from a human perspective but doesn't really register at all in geological time.

Chalara fraxinea is a natural organism, it's moved about on the wind. The condition that is afflicting our ash trees is of natural origin, propagated by a natural process. Why do we think we can affect it, or even think we should? Perhaps Gaia has decided that one kind of ash tree has served its purpose and needs to be replaced.

Let's return to our old king. The childhood story is that Canute got ideas a bit above his station and reckoned he could command the tides, getting his comeuppance and very wet feet in trying to demonstrate his powers. More recent scholarship tells us that Cnut was a very pious man and the demonstration was more likely to be for the benefit of his courtiers, showing them that a mortal king's powers had hard practical limits. Cnut knew that he couldn't prevail against the forces of nature.

So why did a 10th century Danish/English king demonstrate a better grasp of the limits of temporal power than our modern day politicians? Well he seems to have a more mature sense of hs own powers than our politicians do. At least the Canute of the child's story only thought he could halt a tide - our current lot seem to think they can alter the evolution of a species of tree. And most of them think they can change the entire climate.

I'm with Cnut on this one.