"Nature has no interest in the preservation of her dead; her purpose is to start their elements upon the eternal road to life once more." --Loren Eisley
Within a rotting log on a forest floor or pile of autumn leaves, the final act of the food chain occurs. Among the players in this heated drama are the relative giants, such as earthworms, sowbugs, and slugs; fungi, such as molds and mushrooms; and microorganisms, such as bacteria, which are so small that a mere teaspoon could contain billions. Although they may not loom large in our daily thoughts, these decomposers make our lives, well ... liveable. They dine on once-living materials, breaking them into simpler molecules that can be used again as nutrients for plants (our sustenance).
Getting a Closer Look
The earthworm is perhaps the most familiar and visible decomposer. (An acre of soil may house as many as one million of them!) These little "soil plows" carry leaves and other materials into the ground, speeding up decomposition, and bring nutrients and humus to the top. Their tunnels aerate the soil and allow rainwater to drain through. What's more, what they take in their mouths as food comes out the other end as nutrient-rich, pellet-like piles called castings. (Microbes are also at work in worms' digestive tracts, chemically breaking down complex organic compounds into simpler substances.)
Imagine the opportunities for inquiry and discovery rooted in rot and decay. In compost piles and worm bins, students can help decomposers thrive, then explore life science concepts such as nutrient cycles and animal adaptations. They can learn about how organic material clogs our landfills (an estimated 20 to 40 percent!), then take action to reduce these numbers and teach others how to do so.
Such dynamic lessons can be as simple as creating desktop soda bottle worm observatories or as involved as creating a series of outdoor compost bins.