At Yahoo news, an article had the headline "You Should Never Pile Mulch Around A Tree In Your Yard". The article links to another one at Women's Health, but that one does not have the same headline
The Yahoo headline is an alarmist generalization. If followed, it might mean the loss of some trees. Western oaks -- especially the valley white oak (Quercus lobata) and the coast live oak (Quercus agrifolia) -- need a thick mulch of leaves across their entire root zone. These trees are adapted to a climate where significant rain falls only for a few months in the winter. Without a thick mulch, the soil in which they grow will get too hot and dry in the summer.
Of course, Yahoo's Web site provides NO method for reporting problems with its news articles.