Soils are protected from erosion when

• The soil surface is covered by living plants or litter (dead plant material on the soil surface)
• Plant root are deep and hold soil
• Soil contains plenty of organic matter to glue particles together.

Soil surface in the dormant season on a highly productive tropical savanna. Deep-rooted perennials grow enormous amounts of forage, which when trampled by grazers provides excellent soil cover.

See our grassland productivity slide show for examples of soil cover in different climates.