How soil microbes shape ecosystems and climate

Beneath the surface of every field, forest, and garden lies an unseen world that quietly supports life above. Soil microbes—tiny organisms like bacteria, fungi, and protozoa—play an essential role in the health of ecosystems, food production, and the regulation of our planet’s climate.

Unseen engineers of the soil

In just one teaspoon of soil, there can be over a billion microbial cells, spanning thousands of species. These microscopic communities are not only diverse but also incredibly functional. They break down organic matter, recycle nutrients like nitrogen and phosphorus, and protect plants from disease. Without them, soil fertility would decline, crops would suffer, and ecosystems would lose their resilience.

Microbes also improve soil structure. Bacteria release sticky substances that bind soil particles, while fungal networks create underground webs. Together, they enhance aeration, water retention, and root growth—directly influencing crop yield.

Balancing the carbon budget

Soil microbes are key players in the global carbon cycle. As they decompose plant material, they release carbon dioxide (CO₂) and other greenhouse gases. But their role doesn’t stop there. Some microbial byproducts bind with minerals to form stable carbon compounds, effectively locking carbon in the soil for years or even centuries.

More carbon is stored in soil than in the atmosphere. However, rising global temperatures may accelerate microbial respiration, increasing CO₂ emissions from soil. This feedback loop could intensify climate change. The future of our climate, in part, depends on how these microbes respond.

Please also read: Soil as a tool to mitigate climate change

Community matters

Not all microbial communities function the same. Research shows that microbes native to a specific environment often perform better at breaking down local plant material—a phenomenon called the “home-field advantage.” Community composition can influence how quickly nutrients cycle, how much carbon is stored, and how plants grow.

Still, in some soils, especially those low in organic material, factors like moisture or mineral availability may matter more than microbial diversity. Understanding when and where microbial identity makes a difference is crucial for land and climate management.

Adapting to a changing world

Microbial communities can evolve quickly. Changes in climate, land use, or pollution can shift their composition and function. Some microbes adapt by acquiring new genes or traits, while others migrate or disappear altogether. These shifts can reshape how soils store carbon or support plant life.

To better predict these changes, scientists are now integrating microbial processes into soil models. Advanced DNA-based monitoring is helping map microbial populations and their traits across landscapes. The UK, for example, has created the first nationwide microbial monitoring network, offering valuable insights into how soils—and the life within them—are changing.

More than just dirt

Soil microbes are not passive passengers of the environment. They are active agents of change, influencing everything from crop yields to climate regulation. By studying and supporting these invisible communities, we gain tools to combat climate change, restore degraded lands, and secure food and water for the future. Understanding the secret life of soil is no longer a scientific luxury—it’s a necessity.