Root Zone and Soil Storage
						q Climate interacts only with water that is on the surface or in the soil water zone. q The soil water zone extends downward to the depth penetrated by the root of the vegetation. q Soil storage capacity  (field capacity of the soil) is the amount of moisture the soil can hold. q If soil water content increases above the capacity, gravitational forces carry the water downward to the water table, where it becomes groundwater.