What role does leaf shape play in dispersal?

[touma14]

How does leaf shape play a role in dispersal?

[mith]

what is dispersal?

[kotoreru]

I assume he/she means seed/pollen dispersal. BS question and clearly homework imho.

[touma14]

you are funny...

yes it is part of my project and I have absolutly no idea what role a leaf shape plays in its dispersal...its LEAF dispersal, not seed dispersal...what did the question say? seed? no LEAF.

I took measurements of many different leaf shapes and where they land after falling off, but I don't know how else to proceed. Why do trees have such different leaf shapes?

[mith]

But the fact is, shape of the leaf has more to do with the photosynthetic/metabolic needs of the plant than to do with dispersal. In fact, I really don't see any reason for selection of leaf shape in terms of where it is dispersed, unless it has something to do with reproduction.

[MrMistery]

agreed with dave. when a leaf falls off, it is gone for good. nothing grows from it. leaf shape is rather a way to maximise photosynthesis in given environment conditions

[kotoreru]

Mmmnng, what they said. And this: wouldn't it be beneficial for leaves to sink like stones? Sitting at the base of their parent tree would surely put at least some of their matter back into where they came from. That and protecting the soil from heavy rain erosion like they normally would if still on the branch.

Also, touma14, if you want to get funny then your question should have been worded thusly if you wanted to avoid confusion: 'How does leaf shape play a role in THEIR dispersal?'.

[botanygirl]

Hi there, ~ I'm new around here. Hope you don't think I'm hijacking this topic but it brought to mind a question that my 9 year old nephew asked me the other day while we were out for a walk.

He wondered why the leaves if they are not needed any more don't all fall offand individual tree at once like a shower of wedding confetti. (He then went on to fantasise along with his older sister about all the trees everywhere dropping their trees at the same moment!)

Why isn't the reduction in the auxin produced in the leaf which leads to the liberation of ethylene and subsequently abscission triggered uniformly? I thought it might have something to do with the age of the leaf and that I would see a difference between those leaves at the tips of branches. But what I saw instead was that the leaves which were already yellow, and had therefore started to breakdown their chlorophyll and become senescent, were in big patches in isolated parts not related to their age.

If anyone else has any ideas on this I'd love to hear them.

[botanygirl]

I'm thinking that the difference in the tree we saw having patches of autumnal leaves but the rest green is proabably due to the side that was still green was nearer to a building (wondering as well but can't remember if there is a street light that side as well) and therefore these leaves were subjected to warm from the homes and not subjected to the lower temperatures like the other side and therefore don't think its autumn yet.

Next time I go for a walk that way I'll see if there are other trees showing the same effects.

Oh I love nature!

[mcar]

The larger the surface area the better it is photosynthetic ability. Seeds are rather important for dispersal to perpetuate the species of the plants.