I am searching my photo archive for some past pictures, but words will have to suffice for now. In one area, to the right of the main plaza, there is a fountain that bubbles into a channel and this channel flows into an open hole that is the top of another fountains 10-20 feet below in the garden. When first opened, this channel was shaded by a series of pepper trees. Over the years, these trees had become fairly large. Imagine my surprise when I found all of these trees gone and replaced with small, willow-like trees. The replacment had been done in such a fashion that it appeared that those trees had been there all along. There was no sign of turned earth or other disruptions, just new trees.
I have seen this same effect in the main garden itself. Entire beds are replanted. thinned or moved, returning the garden to almost its original state. While I can see a variety of reasons for the maintenance of the gardens, it does strike an odd tone for those of us who live nearby and visit frequently.