Theme of the year: Keep soil alive, protect soil biodiversity

Anyone who has done some gardening work or explored the soil below their feet knows that nature provides shelter to more species than can be seen at first glance. Although we are often unaware of them, soils are teeming with life. They are home to more than 1/4 of our planet’s biodiversity. Yet, we know only 1% of this universe. Some microorganisms, such as bacteria and fungi, are so tiny that they are not visible to the naked eye. Even many of the somewhat larger creatures, such as mites and springtails, are only detectable with a magnifying glass. Among the biggest soil species are woodlice, centipedes, and earthworms.  What they lack in size, however, they compensate for in number: a single teaspoon of healthy soil contains more living organisms than there are people on the planet.

We are dependent on the well-being of all soil creatures

Soil species, like worms, insects, spiders, bacteria are often portrayed as ugly and ‘beastly’ by the general public, habitually receiving little sympathy and appreciation, and those in spite of all the services they provide us for free. Indeed, soil organisms are responsible for many critical ecosystem processes on which humans depend: they support plant growth and purify water (food security and safety), store carbon (climate change), and are vast reservoirs for pharmaceuticals, while also boosting children’s immune system (human health). This hidden community of earthworms, ants, spiders, springtails, centipedes, and beetles fulfills vital roles and provides important services. For example, fungi and springtails digest wood and leaves, providing nutrients to the soil and plants. Earthworms loosen the soil and allow air to enter the ground, making it more productive. Centipedes and spiders control pests and thereby prevent pest species from taking over. Microbes are natural helpers to improve plant growth and food production.

Together, soil organisms form a large feeding community, in which each species has its own special place, accomplishing its specific tasks. For example, the activity of certain organisms promotes decomposition of plant material, which ensures that the farmlands on which we grow our food remain fertile. However, if one link in this chain is missing, the whole system risks losing its balance. This means that soil fertility is decreasing. 

Yet, our soil biodiversity is in great danger

Over the last 200 years, human activities have changed the world tremendously. Human-induced climate change is causing the planet to warm up, coupled with ever-longer periods of drought in some regions. Threats to soil, such as erosion, contamination, salinization, deforestation and sealing compromise soil biodiversity by destroying the habitat of the soil biota. Management practices that reduce the deposition or persistence of organic matter in soils, or bypass biologically mediated nutrient cycling also tend to reduce the size and complexity of soil communities. In addition, unsustainable soil management, such as monoculture, misuse of fertilizers and pesticides, stubble burning, wildfires, and inappropriate land-use change put soil biodiversity more and more under pressure. For example, the use of fields has changed dramatically in recent decades to meet the growing demand for food resultant from a constantly growing world population. In order to respond quickly to this rising demand, large quantities of agrochemicals are now being used in agricultural fields, although they can have major drawbacks both on the environment above and belowground and on the species that live in them.

Once again, protecting nature provides us with the most vital services

As the world seeks to build back better from the current COVID19 pandemic, it is critical to preserve and invest in soil biodiversity as a nature-based solution to many of our current global challenges. For instance, soil biodiversity and agricultural yields are strongly interconnected: soil fertility and its ability to fulfil its key ecological functions depend largely on the biodiversity it contains. Furthermore, soil biodiversity can also support nature-based climate change mitigation and adaptation strategies. Conserved or restored habitats would both reduce emissions and store carbon in soils at lower cost, longer lasting, and with multiple synergistic benefits for a variety of sectors.

Having a wide variety of species in soils is essential for human health and our economy: In term of contribution to ecosystem services, soil biodiversity has also a monetary value with current estimates ranging from 1.5 to 13 trillion US Dollars. An out-and-out treasure beneath our feet!

We can help protect soil biodiversity

In agriculture, sustainable soil management is an integral part of protecting soil biodiversity. Some of these practices are simple, for example, avoiding the removal of vegetation from the soil cover, using soil conservation techniques, managing irrigation through water balance and sensors, adopting a sustainable use of fertilizers, maintaining crop diversity and rotating crops, avoiding monocultures, or composting, where appropriate.

Private companies can also take part. The cosmetic industry would use renewable raw materials, sustainably sourced and/or prepared using green chemistry principles. It would operate projects that both respect biodiversity and reduce the impact that a product has on ecosystems after usage. Responsible agro-industrial companies could also make similar efforts. For example, accompanying farming partners in their transition towards more sustainable practices that preserve soil biodiversity, decrease chemical input, and protect soils.

To sum up, we can all play a role and protect soil biodiversity in our own small way. Starting from private gardens and public parks, revising our purchasing habits, disposing waste properly, and reusing or recycling materials before sending them to a landfill. We can also raise awareness and advocate for the inclusion of soil biodiversity in education, and, last but not least, join us for World Soil Day!

Download the infographic (available in English) in PDF and JPG

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