At my home we've just removed a couple of large, old, rotting (tr)ash trees. I've been pushing my husband to remove them for ten years now and he finally relented. We will miss their shade next summer so we are trying to decide what to plant there.
Another thing that Paul Johnson harped on a lot was diversity in tree populations. After date palm decline wiped out most of the RGV's Canary Island date palms in the late '80s, I can certainly see his point. BUT aesthetically I think that variety is not always as appealing to the eye as a (mostly) monoculture. For myself, I have decided on a larger number of Live Oaks. They perform well although they grow slowly. They live long, are a hard wood, are evergreen - what more could I want! I plan for them to serve as the backdrop to showcase single plantings. Right now our yard contains live oak, mesquite, ebony, anacua, elm, pecan, wild olive, huisache, Texas mountain laurels, pato de chiva, kapok, royal Poinciana, and I must be forgetting something somewhere. Check back here for my thoughts about each of these tree varieties. And get out there and plant a tree this fall!