Day 49: Think about this for a minute. What vegetation can be found in cold climates like the arctic tundra? Why, mosses and lichens, of course! While some vascular plants can withstand freezing temperatures, many others die off as soon as Jack Frost touches them with his paintbrush. What's so special about mosses and lichens in this regard? The answer may be in some part their ability to accumulate sugars in their cells. As cell walls shrink due to dessication, the sugars in the interior of the cell are concentrated into a smaller area, thus lowering the freezing point. Mosses and lichens can adapt quickly to even minor elevations in temperature, thus making it possible to uptake sugars on relatively short notice in a cycle of freeze-thaw events. Although we tend to think of mosses and lichens as primitive, they actually have some pretty clever survival strategies.
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