Climate is a key driver of the distribution of vegetation including, grasslands and woodlands . Along a gradient of precipitation, while maintaining temperature constant, the proportion of trees increases from grass lands, which have no trees, to savannas, which have a mixture of trees and grasses,to a closed-canopy forest. However, the effectof precipitation on the distribution of forest, savannas and tree-less is not always linear. Studies of continental patterns have shown discontinuities in the distribution of woody-plant abundance with precipitation . Grasslands showno tree cover, savannas 20% and closed-canopy forests 80%tree cover. However, the frequency of intermediate states isremarkably very small, highlighting the occurrence of precipitation tipping points where ecosystem can easily shift from one physiognomic state to the other