section_path: Degradation/Causes/Land use intensification
section_name: Land use intensification
paragraph_text: Land use intensification
  
  Grasslands have an extensive history of human activity and disturbance. To feed a growing human population, most of the world's grasslands are converted from natural landscapes to fields of corn, wheat or other crops. Grasslands that have remained largely intact thus far, such as the East African savannas, are in danger of being lost to agriculture. Grasslands are very sensitive to disturbances, such as people hunting and killing key species, or plowing the land to make more space for farms.
  
  Grassland vegetation is often a plagioclimax; it remains dominant in a particular area usually due to grazing, cutting, or natural or man-made fires, all discouraging colonization by and survival of tree and shrub seedlings. Some of the world's largest expanses of grassland are found in the African savanna, and these are maintained by wild herbivores as well as by nomadic pastoralists and their cattle, sheep or goats. Grasslands have an impact on climate change by slower decomposition rates of litter compared to forest environments.
  
  Grasslands may occur naturally or as a result of human activity. Hunting cultures around the world often set regular fires to maintain and extend grasslands and prevent fire-intolerant trees and shrubs from taking hold. The tallgrass prairies in the U.S. Midwest may have been extended eastward into Illinois, Indiana, and Ohio by human agency. Much grassland in northwest Europe developed after the Neolithic Period when people gradually cleared the forest to create areas for raising their livestock.