Not only do leaves make trees look beautiful, their importance in sustaining life on this planet cannot be understated. Their bright green appearance in the spring is an indication of the beginning of a new life cycle. In the summer leaves provide much needed shelter from heat and rain for wildlife and humans alike.
They also serve as the vehicle through which trees produce their own food. Their dramatic beauty in the fall is simply unparalleled. In addition to all of this, properly used as mulch or compost they provide outstanding organic matter and nutrients to the soil called humus.
Soils that have a high humus content, have abundant living biological activity to convert plant residues, leaf litter, animal dung and various biomass into stable humus. Humus gives the soil the ability to absorb and retain moisture. Such soils do not dry out and require significantly less irrigation.
Humus provides a reservoir for the plant nutrients available in the soil for balanced plant growth.
Humus plays a part in supporting soil bacteria. A result from bacterial activity results in binding the small soil particles into a nutty crumb structure to a depth of 30cm or more.
Humus also supports the all important fungil, which form a symbiosis with many plants and are an important factor in the soil food web. The hyphae from these fungi help bind the soil particles to form good soil structure.