Root dynamics of Bouteloua gracilis during short-term recovery from drought.

Following a small rainfall event, surviving roots were able to absorb water at c40% of the rate of new roots, sufficient to restore non-stressed leaf water potentials within one day of watering. New root growth occurred c40h after watering. New roots never accounted for >15% of total root length but they made possible the continued response to increased water availability. The response of leaf water potential was influenced by previous water stress as well as by the amount of water added, but the response of root growth was independent of water stress when 15 mm of water was added and dependent upon water stress in the case of the addition of only 5 mm. -from Authors