I had to move all my orchids out from under a very large Cork oak (Quercus suber)that has developed Phytophthora cinnamomi. An arborist said the tree was getting too much water.
The tree now provides afternoon filtered shade in the new location of my orchids but not in the morning. Plus the greenhouse fabric isn't there to filter them anymore.
What we won't do for our orchids, now applies for me also a many-ton huge (stately) Oak.