About Soil Biodiversity

What is soil biodiversity?

Soil is one of the most biologically diverse environments on Earth hosting an estimated 59% of life on Earth. Beneath our feet, an extraordinary diversity—from bacteria, fungi and microscopic organisms to mites, springtails, insects, earthworms and plant roots—lives and interacts within the soil.

Soil biodiversity is the diversity of life in soil, from genes and microorganisms to species, communities, and the interactions among them. This diversity varies across soils and ecosystems, shaped by factors such as climate, vegetation, soil properties, land use, and disturbance.

Soil organisms are not simply inhabitants of soil. Together, they drive many of the processes that make soils function: decomposing organic matter, cycling nutrients, building soil structure, regulating water, storing carbon, supporting plant growth, and helping protect plants from pests and disease.

Healthy soils depend on diverse and functioning biological communities. Understanding, monitoring, and protecting this diversity is therefore fundamental to sustainable agriculture, climate resilience, and healthy ecosystems.

Soil biodiversity is essential to how soils function. Soil organisms decompose organic matter, recycle nutrients, build and maintain soil structure, regulate water, store and release carbon, and interact with plants and other organisms. These processes support food production, clean water, climate regulation, and healthy ecosystems. Much of what soils do depends on the diversity and interactions of the organisms living within them.
Soil is home to an extraordinary variety of life. This includes bacteria, archaea, fungi, algae, protozoa, nematodes, mites, springtails, insects, earthworms, and many other organisms, as well as plant roots. Some are visible to the naked eye, while others are microscopic. Together, these organisms form complex communities in which species interact with one another and with their physical environment.
Soil organisms perform many of the processes that keep soils alive and functioning. They break down dead plants and animals, release and recycle nutrients, contribute to soil formation and structure, influence water movement, and interact with plant roots and other organisms. Some help plants obtain nutrients or resist disease, while others regulate populations of pests and pathogens. No single organism does all of this—soil functions emerge from diverse communities and their interactions.
Soil biodiversity occurs almost everywhere there is soil, from forests, grasslands, wetlands, deserts, and tundra to agricultural fields, gardens, and urban environments. The organisms present and their abundance can vary greatly between places and even within the same soil. Climate, vegetation, soil properties, moisture, depth, and land use all influence which organisms can live there and how they interact.

We know that soil contains an enormous diversity of life, but much of it remains poorly understood. Many soil organisms have never been formally described, and for many of those we know, we still do not understand their ecological roles. Even less is known about how soil communities change across regions and ecosystems. Improving our knowledge of this hidden biodiversity is essential for understanding and protecting soil ecosystems.
Soil biodiversity is affected by many of the same pressures that affect soils more broadly, including land-use change, intensive agriculture, pollution, soil sealing, erosion, habitat loss, and climate change. These pressures can alter soil conditions and disrupt biological communities. Because different organisms respond differently to environmental change, impacts may not always be visible above ground, but changes in soil biodiversity can affect how soils function.
Protecting soil biodiversity begins with protecting the soils and habitats in which it lives. Practices such as maintaining vegetation and organic matter, reducing unnecessary disturbance, protecting soil from erosion and contamination, and supporting diverse plant communities can help maintain soil life. At a broader scale, we need better knowledge, monitoring, indicators, and policies that recognize soil biodiversity as an essential part of healthy ecosystems.
Soil is a remarkably complex environment. Conditions can change over just a few centimetres, and different organisms live at different depths, in different soil pores, or around plant roots and organic matter. Many are microscopic and difficult to identify. As a result, there is no single method that can capture all soil biodiversity. Understanding changes in soil biodiversity requires approaches that account for this complexity and the diversity of organisms being studied.