Plant and tree "vaccination"

[gradus]

Also on this morning's R4 programme, Oliver Rackham who thinks we should wait and see what happens before writing off our Ash trees. Perhaps there is hope after all.

[Lateralthinking1]

Also on this morning's R4 programme, Oliver Rackham who thinks we should wait and see what happens before writing off our Ash trees. Perhaps there is hope after all.

Yes - 'Saving Species'. It was a very good programme. There was a woman interviewer - sorry, I didn't catch her name - who had a whole list of very sensible questions. All of the contributors were reasonable. It was though interesting to hear their "political" positions. There was the guy who argued that the policy of planting trees had been a disaster - there have been millions upon millions here since 2000 - and that a laissez faire approach was needed. Wait for 100 years and let nature take its course.

More invitingly, Sophie Churchill, Chief Executive of the National Forestry Company, felt that it was a question of doing what was appropriate in any given area. It wouldn't be right just to sit back and wait everywhere. I thought she set out her position effectively. Don't criticise people for planting trees when they did so with good intentions; trees were sent to Holland to mature and then brought back for economic reasons - it wasn't easy to predict that some would be infected and reputable companies were used; there has been a policy of planting many different species of trees in specific areas so that eggs are not placed in one basket; yes, the thinking does need to become more sophisticated - what species is suitable where - but that is happening.

And then, gradus, as you say, Oliver Rackham who has 40 years of experience. He accepted that the situation is serious but is biding his time on whether it is necessary to express fatalism. In his view, the scientific evidence is just not at all consistent or clear yet. Fascinatingly, he felt that the biggest threats to trees were 1. Imports 2. Deer and Squirrels and 3. Climate Change - in that order. Which, in a sense, is where Simon came in with his original thread. While opinion on the programme was contradictory in many places, there was nothing that sounded to me absolutely ridiculous. Clearly there are very many factors involved.

[umslopogaas]

Oliver Rackham? Goodness, there's a name from the past. He was a junior staff member of the Botany Dept. at Cambridge when I was doing my research degree. Widely held to be brilliant, if a bit eccentric. He used to ride around on a bicycle with a basket on the front containing an axe. I'm very glad to hear he's still around. There wouldnt be anyone more knowledgeable about UK woodlands.

[Serial_Apologist]

Oliver Rackham? [...] He used to ride around on a bicycle with a basket on the front containing an axe.

That sounds quite an idea! Could come in useful for those other cyclists who whizz past me patiently waiting at red traffic lights, thus demeaning the reputation of cyclists in general, when I catch up with them!

[umslopogaas]

Yes, I know what you mean. Cyclists, I hate them with a passion, but I console myself with the thought that though they are more mobile than me, I am warmer than them. And I've got a car. Modest item, but if I knock one of those f*****s off their chariot, at least I can transport them to hospital in warmth and gain a few brownie points from the nurses. Always worth having, a positive position with a nurse. They know the facts of life, and are not shy about promulgating them.

[Dave2002]

Always worth having, a positive position with a nurse. They know the facts of life, and are not shy about promulgating them.

Sounds like a right Carry On. And I thought this was a serioius MB and a serious thread!

[umslopogaas]

Tee hee, it might be a bit of a Carry On, but the outcome could be serious enough, though I'm told parenthood is a rewarding experience.

[JFLL]

I know the ash tree is important in numbers, and also significant culturally for its celtic and druidic resonances. But I have to confess that I'v never found it a particularly handsome tree (yes, appalling anthropocentric aesthetic judgment here, I know): so, sad, but - selfishly speaking - I won't miss them as much as I miss the elms...

You would miss them if, like me, you had one beside your house in a landscape fairly bare of single trees. And they are beautiful, not least in allowing the sunlight through to dapple the walls of buildings.

Edit: Perhaps someone might know this. My ash is a large pollarded ash. If it does succumb, what happens if the tree is pollarded again? (I guess the depressing answer might be that the pests would lie in wait and attack any new growth.)

[umslopogaas]

JFLL, I dont know for sure, but I fear you are right. I dont think being pollarded, or not, will make much difference if the disease strikes. But having said that, I am pondering. A pollard puts up a large number of young shoots. They are all susceptible. We now know, courtesy of the BBC website, that the most susceptible time for infection is late summer/early autumn. So, dont do your pollarding in the spring, so that by late summer you have lots of young susceptible shoots. Pollard in autumn, so that the new growth occurs in the spring, and by the time the infection period arrives, your shoots will be out and away from their susceptible phase, too tough for infection.

This might be all nonsense, but if it is, would someone from Forest Research chip in and correct me?

[JFLL]

JFLL, I dont know for sure, but I fear you are right. I dont think being pollarded, or not, will make much difference if the disease strikes. But having said that, I am pondering. A pollard puts up a large number of young shoots. They are all susceptible. We now know, courtesy of the BBC website, that the most susceptible time for infection is late summer/early autumn. So, dont do your pollarding in the spring, so that by late summer you have lots of young susceptible shoots. Pollard in autumn, so that the new growth occurs in the spring, and by the time the infection period arrives, your shoots will be out and away from their susceptible phase, too tough for infection.

This might be all nonsense, but if it is, would someone from Forest Research chip in and correct me?

Thanks, umslopogaas, I didn't know about the most susceptible time for infection. The tree is an old pollard, with a pretty large bole and half a dozen large boughs growing up from it. It obviously hasn't been pollarded for decades -- it was already more or less the same size when we moved in over twenty years ago. (When we removed some ivy a year or two back, we found a small gooseberry bush with even a few gooseberries growing in the bole!) My only hope is that old trees might be less susceptible than young ones. But if it did have to go, obviously leaving the bole there would be a lot less expensive than felling the whole tree.

[Lateralthinking1]

JFLL, I dont know for sure, but I fear you are right. I dont think being pollarded, or not, will make much difference if the disease strikes. But having said that, I am pondering. A pollard puts up a large number of young shoots. They are all susceptible. We now know, courtesy of the BBC website, that the most susceptible time for infection is late summer/early autumn. So, dont do your pollarding in the spring, so that by late summer you have lots of young susceptible shoots. Pollard in autumn, so that the new growth occurs in the spring, and by the time the infection period arrives, your shoots will be out and away from their susceptible phase, too tough for infection.

This might be all nonsense, but if it is, would someone from Forest Research chip in and correct me?

If Beddington is right and trees over 40 years old may not be affected, surely that does not suggest 98% of trees will be lost. Nearly all of the trees in this area have been around since I was born. That is fairly typical. So perhaps pollarding is the problem?

I have always had qualms on seeing well-intentioned people cutting trees back to encourage new growth. If old trees are now damaged because disease gets into new shoots created by pollarding, wouldn't it be advisable to reassess pollarding in general?

[umslopogaas]

I agree about pollarding. Its OK when its done for the reason it was invented: to produce lots of flexible young shoots to weave into baskets or whatever. But I've never thought it was very ornamental, I prefer trees in their natural state.