How does sun affect moss and lichen?
It depends upon the species of mosses and lichens as to where they grow. Some species are very tolerant of intense sunlight and grow on bare rocks and earth in the direct sunlight. Others are more sensitive to the drying effects of the sun and grow in protected sites such as the north side of trees. However where there is enough light and humidity, the mosses and lichens will grow on all sides of the trees or rocks. If you’ve the time and someone is cutting down a tree with moss on the north side of the bark, you could take sections of bark off the tree with the moss attached. (You wouldn’t want to damage a living tree’s bark to obtain the samples.) You could fasten the bark to a post in each direction and see if any of the mosses or lichens survive. It could take a while for the specimens to show deterioration.
