Elephants are not the most common species in African grasslands. And although they are large, their combine biomass is really not that big compared to some of the combined biomass of plants in those habitats. The grasslands contain scattered woody plants, but they are kept in check by the uprooting activities of the elephants. Take away the elephants, and the grasslands convert to forests or to shrublands. The newly growing forests support fewer species than the previous grasslands. What term best describes the role played by elephants in these communities