Mystery orchid growing in the mulch in my yard.?

[Lwagner]

I am new to Miami and growing orchids. I have discovered 5 orchids that have "appeared" in my mulch. 2 orchids I relocated to the Live oak tree that they were found growing under and I think they are happy. The attached pictures are of a different type that have "appeared" and I relocated the first one to the Oak tree as well. After a few weeks I noticed the leaves turned brown. I fear I may have done something terribly wrong and killed it. I removed it from the tree and put it in a pot with the mulch that I originally discovered it growing in. Fast forward a few months and today I walked outside and ........there is another one popping up. The area that these large bulb orchids are growing in is at the edge of the Live Oak canopy. The area is facing South. The first one that "appeared" I put on the North side of the tree. I am guessing that was a mistake as the mulched area keeps producing these plants in the sun. So the 2nd one I dug up and put it in a pot with the same mulch. So NOW what do I do???? And why does my mulch keep having orchids randomly appear???
The history of my property: bought the house 2 years ago and the bimbo (I am a woman so I can call her that) did NOTHING to the house for 18 yrs. I have an extremely small front yard with a LIve Oak and Mahogany. They did not have any orchids growing in them. I had a tree company bring me a load of hardwood mulch to help protect the tree roots while I had my workmen park their trucks in the front yard for a year. I finally got a permit from the city for my new front yard. The sunny area that is producing orchids is about to become stone & pavers I am sick to my stomach but really have no choice. I will hand shovel all of the mulch to another part of the yard in hopes a few more free orchids emerge. Please help me understand how to care for my new friends.