Beneath forests, farms and cities lies one of the most important natural systems on Earth: soil. Yet it has often received far less attention than air, water or forests in environmental debates.
Healthy soil supports food production, stores carbon, filters water and sustains vast communities of microorganisms essential to ecosystems.
Scientists warn, however, that soils in many regions are under pressure from erosion, pollution, overuse and unsustainable farming practices.
When soil degrades, the consequences can be severe: lower crop yields, reduced biodiversity and greater vulnerability to drought or flooding.
This has increased interest in regenerative agriculture, which promotes practices such as reduced tillage, crop rotation and cover planting to rebuild soil health.
Governments and international organisations are also paying more attention to soil as part of climate and food-security strategies.
Experts say protecting soil is not only an agricultural issue but a long-term environmental priority.
The future of nature may depend as much on what lies below the surface as on what grows above it.
