The scientific application being addressed at the Stunt Ranch, a 310-acre reserve in the Santa Monica Mountains, is a long-term investigation of the influence of the 2006-07 Southern California drought conditions on the water relations of important chaparral shrub and tree species that differ in their depth of rooting. Rainfall over this past hydrologic year in Southern California has been less than 25% of normal, making it the driest year on record. Measurements will be made using sap flow sensors to continuously monitor the flow of water through the xylem system of replicated stems of four species to compare their access to soil moisture with plant water stress. Core measurements of air temperature, relative humidity, solar irradiance, rainfall, and soil moisture will be monitored continuously at the same site. The project utilizes a flexible satellite Sensornet gateway adapting new Compact RIO technologies under development for NEON.