“The ground is not eternal”: why biodiversity also needs to be protected underground


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This story by Tara Lohan originally appeared in The developer and is republished here as part of Cover the climate nowa global journalistic collaboration strengthening the coverage of the climate story.

Look down. You may not see the ground beneath your feet as teeming with life, but it is.

Better scientific tools help us understand that dirt isn’t just dirt. Soil life includes microbes like bacteria and fungi; invertebrates such as earthworms and nematodes; plant roots; and even mammals like gophers and badgers that spend some of their time underground.

It’s usually said that a quarter of all biodiversity on the planet lives in the soil, but that’s probably a gross understatement. Many resident species, especially microorganisms such as viruses, bacteria, fungi, and protists, are not yet known to science.

“The published literature is only beginning to unravel the complexity of soil biological systems,” found a 2020 study by researchers at the University of Reading. “We barely know what’s out there, let alone the extent of their functional roles, niche distribution, and how these organisms interact.”

But what scientists do know is that healthy, biodiverse soil communities support a wide variety of functions that sustain life on Earth. This includes nutrient cycling, food production, carbon storage and water filtration.

What happens underground sustains life above ground. And unsurprisingly, if this underground biodiversity is threatened, so are the important functions performed by the soil.

“As soil organisms begin to die out, ecosystems will soon begin to underperform, potentially hampering their vital functions for humanity,” researchers wrote in a 2020 Science study.


Pesticide, spray, wildlife refuge

Spraying pesticides at the Don Edwards National Wildlife Refuge in California. Photo Credit: Don McCullough/Flickr (CC BY-NC 2.0)

Unfortunately, there is evidence that soil biodiversity is declining today – how hard researchers work to determine how hard researchers work to determine this. By just one metric, studies have found that 60-70% of soils in the European Union are now unhealthy.

The threats there – and across the world – are many.

Researchers at the University of Reading narrowed them down to five main areas:

      • Human exploitation, including intensive agriculture, pesticides, fertilizers and genetically modified organisms.
      • Land use change such as deforestation, habitat fragmentation and soil sealing.
      • Soil degradation due to compaction, erosion and loss of nutrients.
      • Climate change, which influences temperature and humidity.
      • The growing threat of plastic pollution.

“Lands are changing [like intensive agriculture] are in tune with climate change,” says Diana H. Wall, professor of biology at Colorado State University and director of the School of Global Environmental Sustainability. “Because what we do is tear up the ground. And this is the habitat of all these species.

When we lose biodiversity in the soil, it leads to a decrease in the soil’s ability to resist disturbance, which could lead to a loss of important functions and even more biodiversity.

Knowledge gaps

Just as new molecular tools have helped researchers understand the microbiome in people’s guts, scientists can now learn much more about the tiny organisms living in soil, Wall says. But while research on soil biodiversity is growing, there are still significant knowledge gaps.

A 2020 study of the “blind spots” of global soil biodiversity and ecosystem function found that most research focused on a single sampling event and did not study the evolution of soil in the soil. same area over time, which the authors say is “essential for assessing trends.” in key taxa and functions, and their vulnerability to global change.

The research was also geographically unbalanced, they found. Temperate zones, which include mixed deciduous forests and the Mediterranean, have been studied more than many tropical zones, tundra or flooded grasslands.

This is not a new problem: another study found that we lacked historical information on soil biodiversity that would help understand baselines on previous land cover and local drivers of biodiversity. Without understanding past conditions, one does not know how things change or why.

Knowledge gaps are not limited to science either. In terms of policy, national and international bodies lack systematic means to monitor and protect soil biodiversity.

“Globally, soil biodiversity is still a blind spot: most Parties to the Biodiversity Convention do not explicitly protect soils and their biodiversity,” found a study published in April in Biological preservation.

CIAT researchers, data collection, erosion

CIAT researchers collect data on soil erosion as part of the Africa Rising Initiative. Photo credit: 2015CIAT/GeorginaSmith / Alliance of Bioversity International and CIAT / Flickr (CC BY-NC-SA 2.0)

To take part

Efforts to better study and protect soil biodiversity have begun to intensify.

One is the Soil Biodiversity Observation Network (Soil BON), co-directed by Wall, which is a coordinated global project to monitor soil biodiversity and ecosystem function to help inform policy.

Wall also directs the Global Soil Biodiversity Initiative, a volunteer scientific network of more than 4,000 researchers studying the vulnerability of below-ground biodiversity. The group recently sent a letter to the United Nations Convention on Biological Diversity asking for action to protect soil biodiversity.

“Knowledge of the importance of the great diversity of flora and fauna that inhabit the ground and support all life above ground should be recognized and included in global policies to protect, restore and promote biodiversity. biodiversity,” the group wrote.

Europe is not waiting for the UN to act.

The Farm to Fork Strategy, part of Europe’s Green New Deal, calls for better soil protection, including halving pesticide use by 2030. The European Union has also launched the plan zero pollution action plan for air, water and soil which aims to improve quality. And the EU could take action further with a soil health law due in 2023.

And while soil health requires more effort from government, there are plenty of changes at the local level and by industries that could help.

In urban areas, the pavement that has sealed the ground can be removed and replaced with vegetation. The construction of green roofs and gardens rich in plant diversity can also contribute to soil biodiversity.

Farmers, Wall says, have also expressed growing interest in soil regeneration and carbon sequestration. “There are definitely things you can do to return organic matter to the soil,” she says. “What we want is a good cover for the ground so that it doesn’t get blown away or washed away. And we also want to make sure that we don’t just cut vegetation down to bare ground.

Scandinavian Green Roof Institute

Scandinavian Green Roof Institute. Photo credit: Sustainable Solutions International / Flickr (CC BY-NC 2.0)

Society also needs to be aware of the chemicals we use in our homes, farms and cities, she says: “Soil pollution is very bad for the organisms that live in the soil, and it’s bad for everyone those who may have a pupation. cycle in the ground.

Soil biodiversity can recover after industrial or agricultural sites are taken out of production, but this can happen slowly and require specialized restoration efforts. In these cases, “microbial grafting combined with the seeding of target plant species could help accelerate these processes,” suggests a 2019 study co-authored by Wall. “Even small changes, which often have a small monetary cost, can increase soil biodiversity and ecosystem services.”

And an even smaller change is also important – getting people to notice and appreciate the role healthy soil plays in our lives and why it’s so vital that we protect it.

“What we really need to realize is that the ground isn’t forever,” Wall says. “Soils are vulnerable, and we know it around the world. Pay attention to the life under your feet, it is fragile.


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