Life in the Soil & Belowground Food Webs

Decomposers are nature’s ultimate recyclers. They break tough cellulose, lignin, and chitin back down into nitrogen, phosphorus, and potassium.

Earthworms act as ecosystem engineers: their burrowing channels aerate tight soils, and their nutrient-dense casts fertilize seedling roots.

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  Bacteria: Single-celled biochemists that consume sugars and simple proteins.
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  Fungi: Branching hyphae that secrete powerful enzymes capable of breaking down solid wood.
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  Springtails (Collembola): Tiny primitive hexapods that graze on fungi and jump with a tail-spring.

How can you prove soil is teeming with hungry life? Bury a pair of 100% white cotton underwear 3 inches deep in the soil and leave it for 60 days!

Cotton is pure plant cellulose—the favorite food of soil microbes and fungi. In active, biologically rich soil, microbes devour the cotton, leaving behind only the synthetic elastic waistband!

Step 1: Use an apple corer or trowel to take a 4-inch deep cylinder of undisturbed forest soil.

Step 2: Place the sample on a clean white cafeteria tray under bright desk lamps.

Step 3: Carefully tease apart soil clumps with tweezers. Use hand lenses to search for moving springtails, mites, centipedes, and fungal threads.

Sub-arctic soils store immense reserves of carbon. When soil is tilled or dried out, oxygen rushes in, bacteria burn carbon rapidly, and CO2 is released into the atmosphere.

By practicing no-till gardening and cover cropping at Tyonek Grown, farmers keep the soil food web undisturbed, trapping carbon in deep, stable humus.

Students complete an illustrated diagram of the soil food web, drawing arrows showing energy flow from decaying birch leaves to worms to robins.

We reflect on how caring for the invisible life below ground protects the visible forests, wildlife, and community gardens above.