NARSARSUAQ, Greenland: A strange thing is happening at the edge of Poul Bjerge's forest, a place so minute and unexpected that it brings to mind the teeny piece of land that Woody Allen's father carries around in the film "Love and Death." Its four oldest trees - in fact, the four oldest pine trees in Greenland, named Rosenvinge's trees after the Dutch botanist who planted them in a mad experiment in 1893 - are waking up. After lapsing into stately, sleepy old age, they are exhibiting new sprinklings of green at their tops, as if someone had glued on fresh...