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 show no tree cover, savannas 20% and closed-canopy forests 80%tree cover. However, the frequency of intermediate states is remarkably very small, highlighting the occurrence of precipitation tipping points where ecosystem can easily shift from one physiognomic state to the other