Transcript: Decomposers

NARRATOR: Hail to the trash collectors. If they didn't march our garbage away, we'd be buried in our own debris. Nature has its own trash collectors. But they do more than just take it away.

These "decomposers," as they're called, eat the world's waste. By digesting it, they recycle it, putting organic matter and nutrients back into the topsoil. Without them, topsoil would become barren and little would grow.

These recyclers, fungi, shown in time lapse, eat the dead leaves and twigs of a forest floor. Fungi roots ooze digestive juices to break down dead plants. Fungi use some of the released minerals, such as calcium and phosphates, to grow. Plant roots can absorb the leftover minerals.

The steam rising from this pile of hay and cow manure is evidence of decomposers too small to see. The feeding frenzy of billions of microorganisms releases heat, causing steam. They turn waste into humus which farmers use to enrich their soil.

The earthworm is perhaps the king of the decomposers. It slithers to the surface for leaves and then pulls them underground to eat in safety. The worm also eats its way through the soil, filtering out bits of organic debris. It releases minerals as it digests its food, leaving some behind as nutritious castings. In a year, the earthworms in just one acre can create 200 tons of fertile topsoil, the weight of 30 elephants. The topsoil in your backyard or neighborhood park has probably passed through the guts of an earthworm many times.

So the next time you see sprouts rise to the sky or watch a flower bloom, give thanks to the decomposers down under. They nourish the soil and all that rises from it.