Actually they are indications of pure air but also lichen on a tree indicates that the tree may be in declining health. Lichen is a combination of algae and fungus and grows very very slowly. Moss is an indication that there needs to be some better air circulation on that tree. Consider a good pruning in early spring.aving lichens and moss on your tree is an indication that the air around your tree is healthy and clean. They do not harm the tree. They have synergistic relationships with the biosphere of the tree that are more interesting if you leave them there.
Officials said Nevadaâs Lake Mead, the 79-year-old reservoir created by the massive Hoover Dam, registered 1,074.98 feet (327.7 meters) above sea level late on Tuesday, but was able to rise above a critical mark by early on Wednesday morning.
Before the filling of Lake Powell (a reservoir of similar size to Lake Mead) behind Glen Canyon Dam, the Colorado River flowed largely unregulated into Lake Mead, making Mead more vulnerable to drought. From 1953 to 1956, the water level fell from 1,200 to 1,085 feet (366 to 331 m).