The best thing for a plant to be might be to have bison living nearby. Scientists recently studied 30 years of data on how bison affect their environment in the Kansas prairie. They found that having bison on a prairie increased the diversity—or number of species—of plants growing there by 86 percent.

Bison help plant diversity in a lot of ways. They eat grasses that keep other species from growing and roll around on the ground, creating pits that catch rain. “Plant diversity means many different kinds of plants to feed many different creatures,” says researcher Scott Collins. “Diversity is always important!”