Why leaves REALLY drop in autumn

[vfem]

Tree poop!

I always blamed it on gravity!?

 

[bid]

I always blamed it on gravity!?

That's only for apple trees!

 

[bid]

DH Brian here:

The problem I have with this theory is the trees would be pooping in their own food source. And as we use leaves in our compost then we would be intentionally adding poop to our food source. Unless the process of composting naturally breaks down the toxins. I don't know. Needs more research.

I agree more research is warranted; there are a lot of variables to consider. Certainly I have more questions than answers. A forest floor is engaged in long term composting. I think we can all agree that the smaller the sizes of the carbon and the nitrogen items that are added the faster they break down and release any nutrients that they contain. Leaves, branches and the dead fall that compose a typical non managed forest floor would not fit that. So the nutrient and the toxins would be released at a much slower rate than the compost we try to make in 6 months or a years time.

Also I wonder what role fire might have in all this. How much it might chemically change some of these toxins. I don't know, just rambling here, but a fire in an unmanaged forest usually burns hotter than a controlled burn or wild fire in a managed forest.

 

[sparkles2307]

I think its an interesting theory, I guess it isnt too far fetched really. But I tend to lean more toward the trees conserving energy. They might push yuckies out into the leaves right before dropping them, but I think thats just one small part of the process, not the main purpose. There is a scab of sorts that forms where the leaf attaches to the tree, when the tree is done giving food to the leaf. Then the leaf starves and falls off. Tada. Profound.

 

[hoodat]

I always though one of the main benefits is that it takes nutrients that have leached deep down into the soil and puts them back on top where they are needed.

 

[reetzblak]

I agree that this can not be the main reason the leaves fall, but the theory of reflection services throughout the life cycle of the leaves on the trees. Evergreen trees as cover, but not all at once like deciduous trees. Some evergreens keep their free time than others, sometimes for several years, depending on the particular species.