Thread by @FlyingQuercus

"Would you know a tree if you saw one?"
(a 3 minute presentation at #napres19)
Sing-along twitter thread with bonus content (1/15)
blogs.napier.ac.uk/researchconfer…

I’m Dan Ridley-Ellis from the Centre for Wood Science & Technology. We research the properties of wood, what properties are needed for the different things we can make from wood, & how those properties are influenced by the way trees grow. (2/15)
blogs.napier.ac.uk/cwst/

This involves trying to think like a tree.
* Trees are usually defined as woody plants
* & wood is usually defined as the substance you find in trees.
(3/15)

While this logic loop leads to no major problems in everyday life (not yours anyway) it does lead one to the wrong idea about what trees are & what wood is for.
But let’s not be silly. We all know a tree when we see one yes? We know, for example, that a willow is a tree?
(4/15)

Well… yes, but even so... trees – they are not a thing. There is really no such thing as a tree – at least in the sense that we can say that cats are a thing – & that lions and tigers are cats. (5/15)

As an example - the conker tree - horse chestnut - is more closely related to broccoli than it is to the sweet chestnut tree.
...& sweet chestnut is more closely related to baked beans. Trees are not a branch on the tree of life. Ironically. (6/15)

https://twitter.com/FlyingQuercus/status/790826294544068608

But it’s not arbitrary & we do tend to group trees according to an evolutionary branch. We talk about softwoods (conifers) & hardwoods (broadleaves). We divide them up like this because hardwood & softwood have some differences that matter – to us, when we make things. (7/15)

en.wikipedia.org/wiki/Wood
But trees are not the only woody plants. Bamboo is quite like wood. People say it is not a tree because it is a grass, but there is no rule anywhere that says you can’t be a tree /&/ a grass. (8/15)

But actually, the basics of woody stuff, which you find in many kinds of plants, was “invented” rather early on. Originally as a kind of environmental suit for plants to exist on land & be more than a few millimetres tall. (9/15)

& Prototaxities, which lived some 400 million years ago, grew 9 metres tall, & did a very good impression of a tree – probably wasn’t even a plant – but a fungus. (10/15)
en.wikipedia.org/wiki/Prototaxi…
en.wikipedia.org/wiki/Tree#Evol…

& this looks like a tree. As big as a tree – taller than a giraffe - & can live for 20 years. It’s a flowering plant so it would be a hardwood, except that it’s trunk contains no wood. It’s a papaya. I’m going to go as far as calling it a papaya tree. en.wikipedia.org/wiki/Papaya (11)

& this – this is a species of willow. No more than 6 cm tall but it can live for more than a century & earlier we agreed willows are trees. (12/15)
en.wikipedia.org/wiki/Salix_her…

What about bonsai? What about if we cut a tree down but it has the potential to grow again? Does it still remain a tree the whole time? (13/15)

Sure. Why not. A tree is “anything that ordinarily one would call a tree”. Not my words, but the considered opinion of the High Court of Justice in England.
(14/15)
designingbuildings.co.uk/wiki/Definitio…

This nonsense matters because the words we use strongly influence how we think.
The danger is that we get to think that our definitions define how things are. They do not, they merely attempt to describe how things are.
& trees, whatever they are, don’t know our rules. (15/15)

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