Welcome to The Environmentalist, your column for understanding the natural world. Today, we’re exploring what’s beneath our feet.
Soil is one of the most underestimated ecosystems on Earth. We walk on it, build on it, dig through it, but rarely think about it. Mind you, a quarter teaspoon of healthy topsoil can contain billions of microorganisms: bacteria, fungi, protozoa, nematodes, arthropods, and microscopic algae. Not millions. Billions. Suddenly, the ground doesn’t feel so empty.
A common misconception is that soil is just ground-up rock. But it is a living system. It forms slowly — sometimes over thousands of years — through the breakdown of minerals, the decay of organic matter, and the constant work of organisms recycling nutrients. Additionally, we have to consider the freezing and thawing that happens in northern regions, just like in British Columbia. What looks like brown dust is actually a biological metropolis with immense biodiversity.
Bacteria decompose organic matter, releasing nitrogen and other nutrients plants need to grow. Fungi form symbiotic relationships with roots, extending their reach through microscopic filaments. Earthworms aerate and mix the soil, improving water infiltration and soil structure. Even teeny-tiny nematodes regulate microbial populations and influence nutrient cycling.
Together, these organisms create what scientists call the soil food web: a complex network of energy transfer and nutrient exchange. Plants feed the system through root exudates, which are chemicals they release into the soil that end up nourishing microbes. And they, in turn, make nutrients available to plants. It is less a hierarchy and more of a circulation of resources.
Soil does more than grow food and plants. Globally, soils store more carbon than the atmosphere and all vegetation combined. That makes them one of the planet’s largest carbon reservoirs. When soils are healthy and undisturbed, they can act as carbon sinks, locking organic matter underground.
Yet, soil is threatened by erosion, urban expansion, over-tillage, and intensive agriculture, leading to that stored carbon being released back into the atmosphere, and they are degrading land faster than it can regenerate. The United Nations has warned that 33 per cent of the world’s soils are moderately to highly degraded. And unlike forests, soil doesn’t grow back in a decade. It rebuilds slowly — about one centimetre of topsoil every thousand years.
There is something quietly profound about the role soil has in our lives. Beneath every forest, every lawn, every farm field, and every step you take there is a living community performing essential work without recognition. No blossoms or feathers, nor dramatic migrations. Just organisms cycling nutrients, storing carbon, filtering water, and holding the planet together — literally.
The next time you step outside, consider this: you are not standing on dirt. You are standing on a highly fragile and rapidly degrading ecosystem that is the base of all life on earth. As the Lorax once said, “Unless someone like you cares a whole awful lot, nothing is going to get better.” So, let’s care about our soils.
