the number of lichens will be more or less on the part of the tree facing roads...expert please answer

Dear Student

The number of lichens on the bark of trees near busy road would be less compared to trees on some distance away from roads. In case of the side of tree facing the road, the number of lichens will be comparatively less (but difference is not much as tree is near the road). Less number of lichens on the bark of trees near busy road because of the air pollution.

Regards