Green Lichen on Tree Bark Nature Poster

Green foliose lichen on rugged tree bark, with organic forms and natural textures in colours of green, yellow, blue and grey, created by the naturally sculpted patterns of tree bark with its soft cloak of lichen. Lichen is an amazing organism. It may be mistaken for moss, but moss and lichen are not related. Moss is a true plant with roots; lichen is the product of a symbiotic relationship between algae and fungus. The type of lichen depends on the variety of algae and fungus that comprise it. There are more than 20,000 species of lichen, making up six percent of the Earth's land mass. It's one of the oldest-lived organisms in the world. Lichen is ubiquitous. It can grow in almost any habitat from the tropics to the tundra, the rain forest to the urban jungle, the desert rocks to the frozen seas. It can grow inside solid rock, or free floating in air. This green lichen prefers to hang out with trees. It doesn't harm the tree and has no parasitic intent. It just likes to live there, and is self-sufficient as it makes all its food through photosynthesis, turning the sun into energy. Lichen releases oxygen as a waste product, which is one reason the air outside smells so fresh. The tree may be getting some benefits too, as the coat of lichen can help preserve water during dry spells. It may offer some protection to the tree trunk and branches too. Browsers like deer and rabbits are fond of nibbling on lichen bark when the winter snows are deep. You can also eat lichen if you're lost in the woods. It's fairly tasteless but full of energy. Don't starve just because you don't want to eat your lichen. This excellent nature photo shows cracks and ridges of bark, different colour shades and textures of the lichen. There was a misty rain the day I took this picture. The lichen is browner when it's dry. The rain makes its skin transparent, showing off the green pigment beneath. This beautiful nature photo is by M Sylvia Chaume, Canada. Happy trails!