Where do grasslands occur and why? What special adaptations do grassland plants have?
Grasslands are found in regions with very seasonal rainfall so there is a dry season. Fire then tends to keep the shrubs or woody perennials in check. Savannah grasslands like the African Serengeti or the Brazilian Cerrado, found in the tropics, tend to have thin porous soil with good drainage. If this region received its rainfall evenly over the year it could support a forest but the rain is very seasonal. The rain can be 20 to 50 inches annually but in the Serengeti it falls March to May, and a shorter season in October and November. The long dry spells allow fires that prevent shrubs and trees to colonize to any density. Savannahs vary from grasslands with rare or very scattered trees & shrubs to open woodlands with mixed grass cover between the trees depending on rainfall patterns. http://au.encarta.msn.com/encyclopedia_7…
