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Grassland plants must be able to cope with low moisture levels and extreme climates. A. Before being stopped by wet areas or rain, fires started by humans have resulted in grasslands, being burned over many square kilometers. B. Grassland plants are not only well adapted to survive grazing, but grazing actually helps maintain high plant diversity. C. Recurring grassland fire serves an essential part in maintaining grasslands, characteristic vegetation. D. Grassland ecosystems have been preserved with the help of Native Americans hunting herbivores such as buffalo and horses. E. Despite grasslands having hot dry summers, plant growth dramatically increases in response to some rainfall. F. Grassland summers are dry, so grassland plant productivity relies largely on the amount of snowfall that accumulates throughout winter.