Biodiversity has been falling on grasslands around the world. A team of fifty scientists did a five year experiment to discover what could be done about it. Here is one they found (quoting from iScience Times):
The most improvement was observed in plots where large, wild and domestic animals were allowed to graze. These animals included cattle, pronghorn, and elk on North America's Great Plains; wildebeests and impala on Africa's Serengeti; and horses, sheep, and ibex in rural India. Places where only small animals like rabbits, voles, and gophers grazed did not show much improvement.
With these results, the researchers proved that grazing animals improved biodiversity by increasing the amount of light reaching the ground.
Read the whole report on iScience Times here: Grazing Animals May Reverse Man-Made Damage to Grasslands Around the World.