Orchids are covered with lichens. Do we worry?

Hello. I am new to the forum and I thank you for your help. We have several orchids of different species growing and living quite well On tall palm trees. They get mist from my irrigation system that is fed by a well every other day, and rain of course. A few of them and the palm tree trunks are covered with green lichens, I believe. I see It on roots and some orchid leaves.

Is this dangerous to the orchids? They look healthy, but I wonder.