It helps prevent soil erosion and, in our gardens, not only keeps the soil healthy and happy, it helps keep in warmth and moisture and keeps out weed seeds. Mulch also helps to hide unsightly drip system tubing. There must be something about nature's plan that pleases humans, for even in the landscaped grounds of office parks and shopping malls you will find plenty of mulch. It has an aesthetic quality that landscape architects insist upon. I have also used cardboard under wood chips as a way of building soil while stopping weeds such as oxalis.
Many choices There are many choices when it comes to mulch.
You can recycle your cardboard and build soil by laying inexpensive wood chips over the cardboard. Wood chips are usually available from your local tree surgeon, sometimes for free. Raking leaves from under trees is sometimes not necessary especially if you are just going to replace the leaves with mulch. Leaves can be a mulch. Even grass clippings can serve as a quick mulch.