What is the ecological importance of the black willow tree, for both humans and nature?

Question

What is the ecological importance of the black willow tree, for both humans and nature?

Answer 1

The black willow, Salix nigra is a fast growing tree with large water-holding capacity and able to hinder clay to be washed away.

http://www.fs.fed.us/ne/delaware/atlas/e...

Like other trees it enlarges the volume of oxygen, clears rain and air from dust.

It brings living space for plants and little animals, ameliorates microclimate ( humidity, temperature ) and embellishes landscape.

Its one of the bee-feeding plants.

The leaves and bark of the willow tree have are used from time immemorial  as a remedy for aches and fever.

Here you should find what I forgot to mention:

http://en.wikipedia.org/wiki/Willow