A TEEMING WORLD

 

The soil beneath our feet—whether in the great outdoors or hidden beneath tiles and asphalt—is an incredible wonder. It teems with life. This soil not only supports plants but is also, and above all, the nourishing foundation for all the seedlings, plants, shrubs, and trees we encounter everywhere.



COUNTLESS NUMBERS

When it comes to the soil, most of us know that, in addition to plant roots, there are all kinds of tiny creatures present, such as ants, termites, earthworms, and the like. These are the easily visible creatures. However, they represent a very small minority compared to the much smaller creatures—in hundreds of species and in countless numbers—that live there and “do their work.” They often cluster around the roots, but even without those roots, the soil teems with a countless “population.” Here I can only mention a few examples to give an impression. I will provide pictures of them later. A good microscope will show you springtails, beetle-like mites, ribbon-shaped earthworms, tardigrades, and if you let your microscope look even deeper, you’ll see an “infinite number” of sometimes hard-to-classify amoebas, protozoa, algae, bacteria, and viruses—all single-celled or multicellular, minuscule but truly alive.

A tablespoon of healthy, humus-rich soil contains a population many times the number of people on our planet—so many times eight billion! A gram of fertile soil can contain billions of microbes and viruses, millions of protozoa and algae, hundreds of microscopic ribbon-shaped worms, dozens of mites and springtails—and a thousand meters of fungal hyphae!

ONE LIVING BEING

Just as everywhere there is life, the soil has also defied human attempts to describe it precisely: living matter is ultimately so rich, so complex, and so innumerable that the soil can best be described as a single living being. A living being that is, in turn, part of the living whole of our Earth, GAIA. I discussed that enormous living whole in my previous contribution on this weblog CREATIVE GAIA.

ORIGINS

Looking back at Earth’s history, we can see that several billion years ago, rocks, mountains, and valleys were formed by earthquakes, volcanic eruptions, colliding “floating” continental plates, and other geological processes. These rocks underwent and continue to undergo constant weathering due to the influence of water, wind, varying temperatures (contraction and expansion), carbon dioxide, and other substances in the air, but also due to all kinds of “small” life that developed on them. Consider, for example, lichens (fig.), which feed on their substrate and thus produce new biological material from anorganical. The same applies to grasses and larger plants, which not only penetrate the inorganic material but also interact with it. It is precisely this interaction between organic and inorganic material that has created a layer of fertile soil. This has been a transformation process lasting millions of years, during which a fertile topsoil layer of 20 to 30 centimeters has formed, which is considered the active root zone. Of course, some roots go deeper, such as those of trees with taproots, but the majority of biological activity still takes place primarily in that topsoil layer.

It was especially in that top layer that a wide variety of “primitive plants” emerged, partly because the rocks had different chemical compositions; some plants were better suited to stronger sunlight, more moisture, stronger winds, and so on. In this way, many types of living soil emerged in which all components work together. It is remarkable how self-regulating systems arose everywhere and continue to arise, systems that also constantly adapt to changing conditions and thus continue to thrive.

TWO LAYERS

In fact, the plants that grow visibly above that soil, together with the soil itself, also form a cooperative “system.” Above and below, two “layers” that help each other in ingenious ways.

Soil is therefore not merely what “supports” or provides stability for everything above it, or what serves solely as a temporary storage shed for nutrients. The plants “above” also nourish the soil in their own way. Of particular importance here is photosynthesis in the green leaves, which absorb the energy of sunlight and the carbon dioxide gas present and, through an ingenious process, convert them into various sugars while releasing oxygen into the environment.
These sugars travel via the downward sap flow to the bacteria and the many other organisms in the soil, serving as nourishment for their growth and functioning.
Conversely, the organisms in the soil synthesize the specific nutrients required by these very plants and deliver them via the roots to the plant, which transports them to the right places through the upward flow of water. 
It is, therefore, a collaboration in which the lives of both the plants and the soil depend on one another. It is a highly active and targeted collaboration. 

IMPRESSIVE SYNERGY

The roots of the plants penetrate the earth, loosening it, creating new spaces for microbes and fungi, forming channels for air and water, and building extensive root systems right beneath our feet. In those spaces, earthworms, snails, arthropods, tardigrades, and their various counterparts consume large volumes of soil and excrete sustainable, nutrient-rich products. In addition, over time, microbes and fungi have developed the ability to break down difficult material. For example, certain microbes can break down the tough cellulose in plant cell walls into valuable organic material, and special fungi can handle the even more stubborn lignin, the substance that (in the bark) gives plants and trees much of their strength.

Other large and (very) small animals, working in specialized groups, break down decaying material, releasing certain chemicals for transport “upward” (e.g., for the color of apples). 

Fungi (fig.) produce kilometer-long threads (tubes) with which they also connect to other plants, provide nourishment, help with disease, and even send signals in case of imminent danger. It’s all almost unimaginable!

HUMUS

You find this wonderful collaboration primarily in what we call humus. It is the most important organic component of fertile soil. It is a dark, mysterious, somewhat oily, and very rich substance, the exact composition of which is still not fully understood. You’ll find stubborn bits of partially decomposed plant cells in it; it contains a wealth of proteins, fats, and sugars. Much of this is bound to mineral particles, which is how the loose, granular structure forms.

Humus is unique to every ecosystem—that is, to every more or less cohesive natural area: a forest, a meadow, a vegetated slope, a pond, a marsh, a stream bank, and so on.
It will come as no surprise that many biologists consider this fertile soil to be the most complex biological material on Earth.

DAMAGE

It is therefore clear just how much damage is caused by human activities / interventions like deforestation, intensive/deep plowing, extensive use of chemicals, and other forms of over-exploitation or abuse of nature and its forces. Unfortunately, we cannot go into that here.
However, to conclude, I can show you a few pictures of some of those active underground inhabitants, who are so important for plant growth, for the climate, and ultimately for our lives.

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BEETLE MITES

These are small (0.2–1.4 mm), armored soil mites that play a crucial role in the ecosystem. They feed primarily on fungi, mosses, and decaying organic matter, making them essential for soil fertility and the decomposition of leaves. They are harmless to plants and humans. 




COLLEMBOLAN or SPRINGTAILS

Springtails are characterized by mouthparts located in the head (a protruding tube) and usually a forked tail that allows them to jump away when in danger. Most species are less than 6 mm long, many only a few millimeters. They typically live in the upper layers of the soil (litter layer) and feed on decaying organic matter and fungi. 

They can occur there in enormous numbers.







TARDIGRADES

These are called water bears or sometimes moss bears in English. They are microscopic, invertebrate creatures (0.1 to 1.5 mm) with eight legs, known for their extreme resistance to dehydration, radiation, cold, and vacuum. They live in moist moss and lichen environments and are true gluttons, consuming large amounts of soil, and their excretions are particularly fertile.



NEMATODES or SOIL WORMS

You encounter these creatures “everywhere”: in freshwater surface waters, at great depths in seawater, in mountains and deserts, in moist soil (which is what we’re discussing here), in numbers and varieties that far exceed those of many other animals. They also occur at great depths within rock, such as 4 km deep in a gold mine in South Africa. The highest numbers however have been observed in tundras and in our northern forests.

CYANOBACTERIA or BLUE-GREEN ALGAE

These are bacteria that derive their energy from photosynthesis. Their blue-green color gave them their name, but they are true bacteria. They are found in a wide variety of environments. They are among the oldest and most widespread organisms on Earth and appeared as early as the Archean, which is the very first phase of the (newly formed) Earth, about 4 billion years ago. 
They were the first organisms to develop the ability to photosynthesis, canturing energy from sunlight and using it to convert water and carbon dioxide into organic compounds. This process releases oxygen as a byproduct. Through this process, cyanobacteria have played a crucial role over billions of years in enriching the Earth’s atmosphere with oxygen, which ultimately led to the evolution of oxygen-loving life forms, such as those we now know across the entire planet.

EARTHWORMS

These deserve to be the “bring-up-the-rear” group, as their importance can hardly be overstated. A great biologist like Charles Darwin (the man behind the theory of natural evolution) dedicated his last major book to them!

The natural behavior of these animals can significantly improve the quality of your plants. These creatures dig small tunnels underground, allowing water to spread more easily through the soil. This makes it easier for plants to absorb water and grow even better. The tunnels also ensure that more oxygen enters the soil, leading to stronger roots. Moreover, the soil stays fresh because earthworms eat everything. They are true scavengers that break down plant material, as well as leaves, plant debris, and other dead matter—and they then excrete all of this “processed” material, ensuring that, thanks to their hard work and large numbers, there are always fresh nutrients in the soil and the soil also retains its aeration.

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Yes, a teeming world, perhaps even more densely populated than the world we humans inhabit, and where their fertile and intelligent cooperation might even serve as an example to us humans!


Johan Muijtjens
late March 2026