Trees are plants with an amazingly wide root structure. These roots, combined with the hyphae network, have been documented to pick up nutrients a hundred yards from the parent structure.
From this blog, you should already understand the importance of how plants metabolize nutrients. These nutrients are systemically in the cell structure of those leaves. Leaves that by design are suppose to fall on the root structure around the tree and decompose into a rich soil around the tree base.
If you ever walk through a natural forest, kick the ground and you will discover an amazingly rich soil. This is what should be around our trees and around plants we are growing. Leaves are one of the most important composting materials we can find.
As with any biological process, studies show that different trees in varying soils will uptake minerals in their own unique ways. So the type of tree, and where it is growing, will have an impact on what nutrients the leaves are putting into out gardens compost. All the studies show that leaves are one of the best "minor" gathering plants to incorporate those important elements that may be missing from our diets.
So how do we utilize these leaves? Everyone who has raked leaves, knows they take way too much space and annoyingly blow around our yard and into our neighbors yard.
Step one is getting them under control. You will find a hundred different gimmicks for gathering leaves, (www.avoidgardenrippoffs.blogspot.com), but the best way to gather leaves is simply with your lawn mower. This will mulch the leaves and help them break down faster, as well as make them much easier to contain in a composter.

Some leaves are difficult to break down such as Oak, Sycamore and Hornbeam. If you have enough space to store these for years they can be used but if not, focus on those leaves that break down. Here is a list of good and bad leaves for composting.
Do not put the leaves in a plastic bag. Plastic can not breath and they will quickly become anaerobic, rotting into such a smelly mass you can't use them. As shown in the photo, wire that can allow oxygen into the leaves will control them and break them down in a manner that does not create the smell.
Most people have the expectation that by next year mulched leaves will break down into a rich soil building compost. Under the right conditions that can be true, but on the realistic side, I incorporate a small amount of leaves on top of my other composting materials every week. The leaves provide a good barrier to inhibit smells the neighbors may complain about, and as the acid from other rotting materials are incorporated into the smaller amount of leaves, I get a faster break down.
Don't be discouraged if it takes time, that is what organic gardening is all about.