The leaves covering the floor of Nowhere Wood are slowly disappearing in the mild December nights. Fog hangs in the air. The wood is preparing for winter and everywhere is quiet and still. Most of the real action is taking place below the ground, but what is making the leaves disappear?
The culprits are earthworms, the little subterranean superheroes that do most of the heavy lifting in Nowhere Wood. There is about 45 million earthworms underground in the wood, with a total biomass equal to about twenty elephants. They are easily the most abundant animal in the wood, but they are so rarely seen.
Earthworms tunnel into the soil making the burrows that are their homes. At night, they come to the surface to drag fallen leaves back down into their burrows. The burrows are also perfect homes for bacteria and fungi.
The bacteria and fungi feed on the leaves, turning them into nutrients that they use as food. This is humus. Earthworms eat the fungi and the humus-rich soil. As they do so, they glue the soil particles together into small clumps. This improves the quality of the soil, making it a perfect environment for plant roots.
Plant roots need plenty water, air and nutrients, all of which are given to the soil by the fungi and earthworms. We can think of earthworms as the soil’s farmers, ploughing the soil for the plants. Without their work, no life could exist in Nowhere Wood.
The famous scientist Charles Darwin studied how plants, earthworms and fungi work together to keep woods alive, and he wrote a famous book about it in 1881. He wrote about earthworms: “It may be doubted whether there are many other animals which have played so important a part in the history of the world, as have these lowly organised creatures.”
- In what ways do you think that soil is alive?
- Think about how the trees, fungi and earthworms work together to keep the wood alive.
Today, Friday 4th December 2020, is World Soil Day 2020. Here is a video celebrating our dependence on soil: