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Monday 15 October 2012

Autumn leaves or twigs?

One of our mature Oak trees never sheds any leaves in Autumn but instead sheds them complete with whole twigs, some up to 2 foot long. I notice this year another Oak which normally only sheds leaves, has this Autumn decided to get rid of the whole twiglets as well. No leaves fall on their own without the accompanying twig,

This seems to be a genetic response, perhaps to growing conditions/weather and is a kind of self-pruning to keep the nutrient uptake in balance with the growth.

The twigs are not snapped but are shed by the tree in the same way as leaves are; that is by the abscision layer of cells that 'cut' the twig from the tree. I am not aware of species other than Oak which do this but would be interested to know if others have seen this. On the photos you will see the rim and the neat abscision at the end of the twig. The convex end fits neatly into the cup left on the tree branch.
 
 

3 comments:

  1. Looks just like the crown of an antler. I have not seen trees do this. It does look like it is some form of stress response as you suggest.

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  2. Never seen this before,what an interesting strategy.

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  3. I had no idea any of our trees did this. Looks more like the type of thing tropicl trees would do.

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