August 18, 2010 I'm Lichen the Tundra

Jeremy and I spent most of the day collecting lichen in the tundra. Lichen is quite possibly my favorite type of organism in the tundra. It is so unique and unlike anything I have ever considered a plant, but it’s only part plant. (We’ll get into that later.) There were brief units in my science classes on them, but I had the opportunity to see, touch, smell, and take them apart...until now.

Lichens come in all shapes and sizes. They are green, beige, black, white, brown, orange, eggshell, and grey. They are short, tall, wide, narrow, circular, stringy, tangled, and straight. They look like concave mushrooms and mini leafless tree. They look like bunched up matted hair and shriveled up disks. They are flat against a surface and they stick out. They have spikes and they are smooth. They look so alien as if you were on the surface of another planet because I never thought I’d ever see anything like them on Earth. They’re lichen and I think they are quite possibly the coolest things in the world.

Lichens are composed of two parts: algae and fungus, although sometimes cynobacteria may take the place of algae. To remember this you can use the rhyme my eighth grade science teacher, Ms. Shaw, taught me: “Algae and fungus to a lichen to each other.” The algae carries out photosynthesis and the fungus acts as an exoskeleton or outer cage that provides structure for the lichen.

Lichens are non-vascular plants. They do not have xylem to transport water or phloem to transport nutrients throughout the organism. They do not have stems, leaves, or roots.

Lichens can grow in very extreme environments where many other plants cannot. They can handle extreme temperatures that are common in the Arctic tundra. They can grow on bare rock surfaces because the do not have roots. They can attach themselves to mosses in the tundra, leaves in the rainforest, or walls in cities. They can conserve water when they experience periods of draught. They have even survived the vacuum, extreme cold, and radiation of space. (Check out the European Space Agency’s article at http://www.esa.int/esaHS/SEMUJM638FE_index_0.html.)

On the North Slope tundra, there are lichens everywhere, especially in Barrow. In one square inch you might find twenty different lichen species in addition to mosses and vascular plants. It’s hard to say which one is my favorite but I’ll show you a few that I really like.