The more plants covering the ground in damaged savanna pastures in Brazil, the less soil gets washed away — and plants explain a big chunk of why some areas lose more soil than others.

Most of the eroded land in a Brazilian savanna watershed is in damaged pasture areas, and the biggest chunk of that land loses soil at a rate of 20 to 40 tons per hectare every year.

Most of the pastureland in this part of Brazil's savanna is somewhat damaged — not the worst, but not healthy either — and this 'medium damage' covers more area than any other type.