The objective of this study was to investigate the water use of managed southern pine and natural hardwood forests as related to climate data and to use NASA's AIRSAR (Airborne Synthetic Aperture Radar) estimates of leaf area index for each forest type to estimate region-wide forest water use. Here we summarize the results from five years of study on the water use of a managed loblollo pine plantation, and a natural hardwood forest for one year each, in Duke Forest, North Carolina.