How many tree species do you have in your yard?

[JDPriestly]

7. We live in the city on a city-sized lot.

It was at one time part of an orchard. From the orchard we still have three avocados, two fig trees and an apricot tree which volunteered after a very large apricot tree that was on the property when we moved in died. We also have at least two pomegranate trees or bushes (not sure which they really are). Finally, we have two rather large ornamental trees, but I don't know what kinds of trees they are.

I woke up one recent morning to find that the inner core of one of our avocado trees had rotted and that the rotted core had fallen out of or oozed out of the tree. So now we have a hollow tree. We aren't certain what to do about it.