The problem with soils: a living, unknown and very unprotected world

Although we tend to pay more attention to furry mammals and leafy trees, beneath our feet lies a fascinating world that teems with life.

Insects, fungi, earthworms and microscopic alien-like creatures are some of the inhabitants of the earth that contribute to the recycling of nutrients, the regulation of the water cycle and the storage of carbon dioxide (CO2), allowing healthy soils and fertile plants that provide us with food and sustain the planet we know.

And it is that soils are the basis of all terrestrial ecosystems.

However, they face great threats globally, while their ecological attributes are often overlooked in political decisions and in the management of protected areas.

This is one of the conclusions of a study published in the journal

the result of the work of an international team of scientists who carried out the first global assessment of

for soil conservation.

"The main result we obtained was that the soils in areas of the world, in which their biodiversity is even more important than the biodiversity of plants or mammals, are not effectively under conservation measures," explains Carlos A. Guerra, a researcher at the Center. German Institute for Integrative Biodiversity Research (iDiv).

"This happens because nobody gives them the importance and part of the conservation measures that exist for the soil are for productive purposes, that is, to protect their fertility, without looking at the unique aspect of biodiversity they have," he says.

Soil biodiversity is key to conserving nature and its benefits, but it is not usually considered in public policies or in protected areas.Vicente Valdés Guzmán

The previous reflection constitutes a call for attention, since, as Fernando Alfaro, associate professor and director of the GEMA Center of the Universidad Mayor (Chile) explains, "soils are a critical component of ecosystems that contribute to the regulation of essential resources , such as nutrients, energy and water, among many others”.

To get an idea, the research included more than 10,000 observations of biodiversity, that is, of invertebrate animals (such as insects), fungi, bacteria, protists and archaea, and other indicators in 615 soil samples from all continents.

They then analyzed three ecological dimensions of the soil: species richness, the uniqueness of its biological communities, and the so-called ecosystem services, that is, the benefits they provide, such as water regulation and carbon storage.

In this way, they identified the priority points for soil conservation, which would be found mainly in the tropics, in North America, in northern Europe and in Asia.

To begin with, the soils of temperate ecosystems, such as some areas of Europe, show greater local biodiversity, that is, a high variety of species.

Instead, Alfaro details that “high singularity values ​​can be observed in some typical Latin American environments such as tropical forests (for example, southern Amazonia) and arid ecosystems (such as the Atacama desert).

In these environments you can find soil biological communities made up of groups of singular species and, generally, restricted to these particular areas”.

Guerra explains, for his part: “In the tropics, communities are very unique, and there is not much diversity locally.

Imagine that you go to a place and find 10 species, and then you move a kilometer and you have another 10 different species.

The communities are very different.

And in other areas, such as the Pacific coast of South America or even Europe itself, what they have is a very large specific local diversity”.

In other words: it is not enough to look at the number of species, but also at how unique and different are the communities they make up in the soil.

The benefits of nature reach their peak in colder latitudes, such as "near the Arctic, in the tundra, where there are areas that are very rich in carbon," points out the iDiv researcher, who points out that the tropics, deserts and high altitude areas such as the Alps or the Himalayas "have a mix of diversity, uniqueness and ecosystem services that are worth protecting on a global scale."

Despite this, the ecological values ​​of soils are often omitted in decision-making, which entails a series of risks.

The ground as a living space

"There is nothing that grows in the soil that does not depend on its diversity," underlines Guerra, alluding to the pressing need to safeguard the integrity of the soil.

However, information on soils has long focused on their physical or chemical properties, rather than on their biological and ecological aspects.

In addition, public policies and the management of protected areas do not usually consider soils from the perspective of their biodiversity.

In fact, when the researchers compared priority soil conservation hotspots with current protected areas, they found that around half of the identified

are not under any official conservation measures.

This is because official protection figures have been designed to protect plants, birds or mammals, but, although it is obvious, all these species require an ecosystem supported by soils to survive.

“When we look for actions related to the soil in the plans of the protected areas, they do not exist.

There is no single measure that is effective for the protection of soil biodiversity”, laments Guerra.

Based on this background, Alfaro states that "this type of study precisely tries to enrich our knowledge about the biological (such as diversity) and functional characteristics of soils, in order to provide inputs that allow decision makers to generate consistent conservation policies." to the needs of the 21st century, such as those presented by global change scenarios”.

And it is that soils play a key role in the conservation of nature in general and in mitigating the effects of the climate crisis, just to name a few of its multiple contributions.

But they are, in turn, vulnerable to the same climate change and to the intensification of their use (such as deforestation, contamination, erosion, among others).

Arid ecosystems - such as the Atacama desert - are home to the most unique soil communities.Fernando Alfaro

For example, soil biodiversity decreases when large-scale agricultural monocultures are established and external inputs such as synthetic fertilizers and pesticides are used that kill bacteria, fungi, protists and many other inhabitants that strengthen the vitality of the earth.

This entails a series of consequences, such as the loss of food productivity.

For the same reason, there are companies that sell microbial inoculants, that is, a set of microorganisms to recover the diversity (and with it, the health) of the soil, in an attempt to cushion the effects of industrial agriculture.

But that is not all.

The loss of soil biodiversity can even lead to a greater presence of pathogenic microorganisms (which can affect, for example, plants), as has been reported in urban areas and also in agricultural landscapes.

As Guerra explains: “When you remove a forest to use that soil for agricultural purposes, you kill what you have and the proportion of pathogens increases.

And that means that later you have no production and the displacement of communities occurs.”

In other words, the vicious cycle is perpetuated.

For this reason, Guerra points to the need to "protect the soil as a living space", starting by considering it not only in agricultural activity, but also in forest management and conservation initiatives, among other human activities.

The team of researchers also calls for prioritizing the protection of its nature in international policies and negotiations of biodiversity objectives for 2030.

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