Omar might be thinking about the use of cypress mulch - a very bad thing to do. Thousands of acres of cypress trees are logged every year to produce cypress mulch. There are many alternatives, as Umbra suggested.

The one thing I can think of that is ecologically unpleasant about mulching is if you are actually using a chipper/shredder to create mulch material from branches, etc.  My family's chipper/shredder has a gross 2 stroke engine that spews out fumes like no other.  So be wary if you've got respiratory problems when using these machines; they do a great job and will help in the mulch production, but they are dirty.

Why not try some spoiled hay?  Make a trip to visit your local farmer (one with cows, horses, sheep, etc.) and see if they have some leftover hay from the winter.  It won't keep for them to use for next year, but it sure makes great mulch.  Pile it deep around your emerging veggies and it cuts way down on weeding.  Adds great nutrients.  Straw works too, but it takes longer to degrade and doesn't have as many good nutrients.  For more details about this type of intensive mulching track down a book by Ruth Stout about her gardening methods - she wrote several.  Happy mulching!

In Minneapolis, the Park and Rec Board chips up all of the their fallen wood - trees struck by lightning, blown down in storms, trimmings from general maintenance, etc, etc.  They then leave the wood chips in parking lots at several parks around the city and are free for anyone to pick up.  So, see if your city has anything similar.