It's getting to be that time of year when the lawn seems to always need work. Time to bust out the lawn mower and weed whacker. As much as you would just like to get the job done, it is always important to be careful around your trees. Mechanical damage from mowers and trimmers is one of the most common causes of harm to trees.
The small wounds caused by little cuts and scratches can open the tree up to a host of pests, especially since the damage is right at ground level. Even the smallest cut can eventually turn into a large, ugly wound and because it is at the base of the tree it can significantly reduce its structural integrity.
Prevention can be as simple as just being extra careful. But if you have someone else do any of the work for you just remember that one "oops!" can be all it takes. There are plenty of ways to protect against this including fencing, mulch beds and protective collars.