This is part one of the “Below Our Feet” series. This series of articles aims to shine a light on the mysterious underground world of plant life beneath our feet. Held together by roots, soil organisms, bacteria, and fungi run this underground world of decomposing plant material. Plants whose aboveground parts we might recognize easily look completely different below the ground. This darker, less familiar side of plants and the fascinating workings of their underground world are what we will explore in this series of articles about the Rhizosphere.

Roots on the edge: Holding the soil and holding on. Photo taken by Jarle Refsnes

The Rhizopshere: Where roots rule

As sedentary organisms, plants rely on their roots to anchor them in place and access water, food, and nutrients. The Rhizosphere is the nutrient-rich region of soil immediately surrounding plant roots. This region is highly dynamic and supports a dense and diverse biological community. Roots are not to be underestimated. Their growing tips can exert enormous pressure to push their way through the soil. If you have witnessed roots lift up pavement or pierce a basement floor, you know how strong roots really are.

Yet roots are capable of so much more! Their special abilities range from water filtration and retention, to soil health and fertility, to climate, disease, flood, drought, and erosion control. Known among experts in the field as the “new frontier,” the Rhizosphere becomes the stage for the secret superpowers of plants. As we expand our knowledge and understanding of the ecological interactions in the Rhizosphere, we can support this region to improve plant productivity, ecosystem resilience, and environmental quality. 

Roots in the spotlight

When I was young, I loved playing in the “dirt”, building fantasy worlds for imaginary communities. Maybe that’s where my fascination for the world right underneath our feet comes from, a place so close yet underexplored. In this other world, a diverse community is in the constant process of composing (and decomposing) complex structures that support our collective survival.

The roots delineate the possibilities of soil architecture, while the building blocks come from soil microbes who draw carbon from decomposing plant material to create channels through which water, oxygen, and nutrients flow. Finally, soil engineers like earthworms and mites take these building blocks to construct even larger passages, forming a sophisticated underground labyrinth that buzzes with life under the right conditions. In a handful of soil, there can be billions of Rhizosphere inhabitants who can only be seen through a microscope.

Uprooted: Roots on the surface. Photo taken by Tom Saunders

An underground world under attack

Directly below our feet, the Rhizosphere and everyone who dwells there is directly affected by our actions. Soil compaction, logging, tillage, fertilizers, pesticides and other human disturbances wreak havoc on soil communities, dismantling their intricate architecture and destroying the passages crucial for water, oxygen, and nutrient transport. 

In many ways, our lives above ground are closely tied to life below ground. Most of our food, fibre, and medicine is derived from plants. If their underground transportation system collapses at a global scale, our supply chain will experience serious shortages too. Soil degradation is a threat of global significance, its impact often going unnoticed until it’s too late, leading to droughts, floods, erosion, and loss of soil fertility.

A climate solution waiting underground

Aside from the common benefits, such as food, fibre, and medicine, plants provide us with so much more. A healthy, functional Rhizosphere acts as a natural carbon sink. Aboveground, plants breathe in carbon dioxide, one of the major greenhouse gasses driving us into climate breakdown. Through photosynthesis, plants convert carbon dioxide and store it in the form of organic carbon. New research suggests that the more intact roots are present in the soil, the greater carbon storage rates and overall carbon sequestration. This reveals the Rhizosphere’s significance for curbing climate change.

Similarly, when plants die, their bodies fall to the ground. Soil organisms, bacteria, and fungi come to feast, pulling the carbon and other nutrients stored in the plants’ leaves and stems back underground with them. In this way, the Rhizosphere acts as a natural twofold carbon sink, representing one of the most accessible carbon capture technologies of all. By planting perennials, avoiding soil compaction, and leaving plants to decompose on the land, we can help roots do their job and store away the carbon dioxide we emit.

The plant root-soil interface: Weathered root bulb sticking out of the ground. Photo taken by Michael Mueller

Radiant roots

The Rhizosphere, as it turns out, is anything but a boring mass of roots and dead plants. Subsurface soil is filled with living organisms, self-organizing themselves into a mesmerizing underground world that works to our advantage. Ecological restoration has an important influence on soil ecosystems. Through protecting the Rhizosphere from harm and strengthening native plant communities, ecosystem restoration practices help plants balance the Earth’s carbon, water, oxygen, and nutrient cycles. By keeping roots in the soil, raising the diversity of plant species, and adding nutrients in the form of woodchips or decomposing trees, we can encourage soil organisms, bacteria, and fungi to settle in the ground, bringing it back alive. In this way, ecological restoration as practiced and promoted by the Mayne Island Conservancy Society supports healthy above and below ground ecosystems. Feel free to contact us to learn more about how you can support the Rhizosphere or to book a free landholder consultation.

For further reading

Who lives in a handful of soil

Understanding Rhizosphere processes to help save the environment

The Rhizosphere and why it matters for our global food system

1 Comment

Gin Nielsen · June 4, 2022 at 9:20 am

Thank you for sharing some fascinating information about the underground world.
A whole universe awaits our respectful research.

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