Livestock like Tan sheep can spread plant seeds through their dung on the dry grasslands of the Loess Plateau. The researchers studied how the seed bank in sheep dung is affected by grazing season and stocking rate. They found that small, round seeds are best for dispersal through dung. Winter grazing led to more diverse plant species in the dung seed bank compared to summer grazing. The number of seeds germinated was not affected by stocking rate. This shows that grazing by Tan sheep helps plants spread and adapt to the tough environment of semiarid areas.