Ricky Novotny, age 11, of Sioux City, Iowa, for his question:

What exactly is the tundra?

We borrowed the word from Lapland, from where the low lying tundra spreads east and west around the Arctic Circle. There are no trees on the tundra plains, because a few feet below the surface the soil is frozen with permanent frost. During the long, dark Arctic winter, the tundra sleeps below snow, while bitter blizzards howl overhead. The scene appears to be nothing more than a desolate frozen wasteland.

But finally spring returns with its unbelievable magic. The surface thaws a few feet down, the melting snow forms puddles and soggy marshes. And suddenly the lifeless tundra comes alive with teeming plants and animals. Swarming insects throng the air, birds flock in from afar to build their nests. Four footed hunters and hunted animals dart here and there. And everywhere the tundra sprouts low growing greenery and bursting blossoms that rival the rainbow. This is a major earth region that ecologists hope to protect from matt and his often destructive works.