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.
Centuries of rain and snow filled the caldera creating Crater Lake. With a depth of 1932 feet (589 meters), Crater Lake is the deepest lake in the United States and the seventh deepest lake in the world. Collapse calderas form when a large magma chamber is emptied by a volcanic eruption or by subsurface magma movement. The unsupported rock that forms the roof of the magma chamber then collapses to form a large crater. Crater Lake and many other calderas are thought to have formed by this process.