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Stoke on Science-The A-Z: D is for decomposers

Jade Harvey-Berrill
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Earth worms are decomposers. (Photo via Pixabay)

Jade Harvey-Berrill

Stoke on Science

Below our feet, currently buried beneath the wintery snow, in the dark, podzolic soil of our region, dwells a restless society.

Billions of organisms writhing around in the pitch black with a common goal, a purpose they pursue their entire lives.

They are the refuse recyclers of Earth. The decomposers.

This society of recyclers – detritovores to give them their proper title – are made up of fungi, bacteria and invertebrates, of which the most common are worms, flies, millipedes and sow bugs (woodlice). Their entire existence is based on their ability to recycle the detritus of Earth’s inhabitants.

Apart from my apparent childhood obsession with attempting to eat them, earthworms haven’t really filtered into my consciousness in adulthood, until I started teaching a program about Ecosystems for Wildsight, here in Revy.

During my research, I learned that in Canada that almost all of Canada’s earthworms were wiped out in the last glaciation (around 12,000 year before present) as the top surface of soil was scraped off by the thick glaciers, taking our poor wriggly friends with them, to be swept into the oceans and killed.

Newer research has discovered there are species that survived the glaciation, specifically in unglaciated warmer soils on the west coast of the continent on Haida Gwaii, Vancouver Island and along the northwest coast of the United States.

According E-Fauna BC (2017), these native earthworms or “ancient earthworms” are forest-dwelling species found in the forest soils.

There are four of these ancient species alive today. (I won’t write the scientific names, you won’t remember them.) I like to think of these four as the Yoda’s of the soil world.

Here, from their wrinkly miniature thrones, they dictate the lives of their insect subjects, passing down the stories of escaping the ice by migrating to the warmer coast.

To date there are 24 taxa of worms in B.C. Of these, 18, like me, are European imports. Invasive if you will. Like all invasive species, they are not ideal for supporting native species, and in Ontario they want rid of these Europeans. Not the humans, the worms I mean.

Regardless of origin, the worms go about their work delighting in their role of digesting rotting plants, animal matter, fungi, and bacteria as they gobble the soil up. The waste that comes out of their bodies at the other end contains important minerals and nutrients ready for plants to absorb.

So just think, when spring arrives and you walk barefoot through the forest, you are walking primarily through the poop of worms. Lovely.

The soil they live in took billions of years to form. Early rock on our Earth was weathered by wind, rain and snow.

Then around 350 million years ago, plants made their way onto the land and together with bacteria, anchored themselves to the ground. This process started to crumble and release bits of rocks providing the plants with nutrients. Over millions of years the dead bodies and remnants of animals and plants mixed with the powdered rock to create soil. Et voila!

A mere pinch of our soil can contain up to a million fungi and a billion bacteria. These plants and animals feast upon each other, using the air they create as they move, and the moisture retained in air spaces between the soil’s particles to survive. As they excrete their waste, they enrich the soil and when they die, they enrich it even more.

When I teach my kids program, we search for decomposers and once we find them, we imagine they are on strike and students have to take their jobs. The soil aerators are sick of creating air spaces for roots of plants and other creatures to move through, so the kids have to find a stick and poke holes in the soil…for eternity!

They soon want to trade jobs.

But how about the leaf chompers? It surely would be more fun to clean up all the leaves off the forest floor by eating them? Students veto this one immediately.

I support their decision. Not to mention the rock-breaker downers and dead body cleaner uppers. It’s not the most glamorous job in the natural world for sure, the kids want none of it.

If these decomposers didn’t exist, the Earth’s surface would be an impassable mess of filth.

There would be no biodiversity of plants as nutrients would not be cycled back into the system.

To the tops of the trees would be solid walls of death and rotting material. Yuck.

So, it’s a new year so I had better make some reference to the passage of time and new beginnings.

In fact, as we trundle through life into the next orbit around the sun, and if you are over the age of 30, as I am, you are beginning, you are beginning your own slow decomposition. How delightful indeed– as a human you don’t have to wait until death!

On a positive note, I like to think myself lucky that my decomposition, rather than being solely in the ground, is occurring in a beautiful place, full of wonderful experiences and people.

And so, as I go into 2021, I am planning to remind myself that each day living is one where I am not a dead something on the forest floor and that I will enjoy it.

And also I will, and I urge you also to be, kind to the earthworms and other horrible looking bugs in the forest, they are important.

Jade Harvey-Berrill holds a BSc 1st Class HONS in Physical Geography. She is the director of Stoked on Science, a local science and outdoor education company where she delivers science and environment education programs in Revelstoke and across the Columbia Basin. For the past 10 years she has written and delivered science workshops and field trips in schools and she now creates after school recreation programs for the City of Revelstoke.